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Biscogniauxia: A genus of latent invaders
Abstract
The genus Biscogniauxia, a member of the family Xylariaceae, has a worldwide distribution with over 50 taxa recognised. Biscogniauxia mediterranea is well known as the causative agent of charcoal canker in cork oak and is a serious problem in Portugal. Other species also cause canker under specific conditions. There is good evidence that these species occur in healthy living trees as endophytes and then become invasive under water stress conditions. The ability of B. nummularia, B. nothofagi and B. uniapiculata to cause cankers in Fagus, Nothofagus and Eucalyptus respectively is reported here.
... Some species of Biscogniauxia are well-known pathogens of Beech trees: Biscogniauxia mediterranea (De Not.) Kuntze and B. nummularia (Bull.) Kuntze in Europe (Nugent et al., 2005;Patejuk et al., 2021) (Nugent et al., 2005). Although most xylariaceous fungi usually present a saprophyte lifestyle, Ju et al. (1998) stated that Biscogniauxia species are probably pathogens and facultative saprophytes, since it is also found on dead material. ...
... Some species of Biscogniauxia are well-known pathogens of Beech trees: Biscogniauxia mediterranea (De Not.) Kuntze and B. nummularia (Bull.) Kuntze in Europe (Nugent et al., 2005;Patejuk et al., 2021) (Nugent et al., 2005). Although most xylariaceous fungi usually present a saprophyte lifestyle, Ju et al. (1998) stated that Biscogniauxia species are probably pathogens and facultative saprophytes, since it is also found on dead material. ...
... This is not the first report of B. uniapiculata on Psidium guajava or a host of the Family Myrtaceae, this species is well-known in East Asia and Hawaii (Rogers & Ju, 2012). It was reported by Nugent et al. (2005) as the causative agent of Canker on Eucalyptus, although we are not certain if it is pathogenic to P. guajava and further studies should be done to prove its pathogenicity to this host. Stromata: perithecioid, subglobose to spherical, gregarious, 0.5-1.3 ...
The xylariaceous fungi are among the most diverse group of fungi found on the Tropics, some genera reaching over 100 known species and colonizing different hosts and substrates. Although most of them are saprobes, some species present pathogenic behaviour, causing from root rot to canker. The present study brings the first report of Biscogniauxia citriformis var. macrospora, B. uniapiculata(Graphostromataceae) and Stilbohypoxylon samuelsii (Xylariaceae) from Brazil and Kretzschmaria micropus (Xylariaceae) from Bahia, contributing to the knowledge of the xylariaceous fungi and Brazilian Funga. Contribuição ao conhecimento dos gêneros de ascomicetos Biscogniauxia (Graphostromataceae), Kretzschmaria e Stilbohypoxylon (Xylariaceae) na Bahia, Brasil. Os fungos xylariáceos estão entre os grupos mais diversos encontrados nos Trópicos, alguns gêneros com mais de 100 espécies conhecidas, colonizando diferentes hospedeiros e substratos. Apesar de a maioria ser sapróbia, algumas espécies são conhecidas por demonstrar comportamento patogênico, causando desde podridão radicular a cancro. O presente estudo apresenta o primeiro relato de Biscogniauxia citriformis var. macrospora, B. uniapiculata (Graphostromataceae) e Stilbohypoxylon samuelsii (Xylariaceae) para o Brasil e Kretzschmaria micropus (Xylariaceae) para a Bahia, contribuindo com o conhecimento dos fungos xilariáceos e a Funga Brasileira.
... On the basis of these records and frequent detection in woody plants, we propose that the identified isolate of genus Chaetomium could be a true endophyte. Nugent et al. (2005) found B. nummularia to be widely occurring as an endophyte in beech trees in southern England and parts of Wales, with the development of stromata only on freshly detached branches or on dying branches still attached to the tree. Rogers (2000) referred to such xylariaceous fungi as 'sneaky' , preferring to think of them as latent invaders developing as the host becomes weakened. ...
... Biscogniauxia nummularia is also associated with severe beech-decline events recorded in southern Italy (Granata and Whal-ley, 1994;Granata and Sidoti, 2004). Based on field surveys and experimental results, Biscogniauxia nummularia is evidently linked to canker disease in waterstressed host trees (Hendry et al., 1998(Hendry et al., , 2002Nugent et al., 2005). On the basis of the presented citations, we propose that the identified isolate of Biscogniauxia can be listed as a true endophyte in olives as well as a stress, i.e., opportunistic, pathogen. ...
... In general, all isolated fungi from the olive tissue culture have endophytic potential as well as saprotrophic, but only Biscogniauxia nummularia possessed some pathogenic ability (Nugent et al., 2005). Biscogniauxia nummularia has never previously been isolated from Olea europaea. ...
The primary aim of this study was to establish a micropropagation procedure for the Slovenian frost-tolerant olive cultivar 'Istrska belica'. Establishing an in vitro culture was very difficult due to constant contaminations, tissue browning and stunted shoot growth. A sterile shoot culture was finally achieved by washing with running tap water, immersing in a mixture of ascorbic and citric acid and sterilizing with 70% ethanol and dichloroisocyanuric acid. Shoot growth was optimal on DKW medium supplemented with 4 mg/L of 2iP. Even in optimized conditions, sporadic fungal outbursts occurred. Fungi were isolated and their taxonomic origin was determined by morphological observation and molecular identification. Based on BLAST queries in the NCBI database, five genera of fungi were identified: Cladosporium, Chaetomium, Preussia, Biscogniauxia and Sistotrema, the last three genera being isolated from olives for the first time. A detailed literature search was performed to provide data on previous reports of these genera in relation to their putative endophytic presence and their possible pathogenic status. This is the first study reporting the presence of endophytic fungi in olive tissue culture. The information provided in this work can be very useful for the optimization of micropropagation protocols of recalcitrant olive cultivars and can potentially improve field performance of nursery plants.
... B. mediterranea is a xylariaceous ascomycete that is typically associated with stressed trees that have been subjected to drought, fires, and mechanical injuries; Nugent et al., (2005) reported that water stress was the primary factor in trees' susceptibility to B. mediterranea attacks. The fungus can exist in the host tissues as an endophyte (Mazzaglia et al., 2001); however, under stress, it quickly invades bark and woody tissues, manifesting as fungal stroma on branches and trunks (Collado et al., 2001). ...
... Other species in this genus can cause canker under certain circumstances. According to strong data, these species serve as endophytes in healthy trees at first and become invasive during periods of water scarcity (Nugent et al., 2005;Yangui et al., 2019). ...
... Biscogniauxia was typified by B. nummularia, which was discovered in living plant tissues and rapidly induces strip-cankers and wood decay (Granata et al. 2004, Nugent et al. 2005, Luchi et al. 2015. A key for the species of Biscogniauxia was provided by Ju et al. (1998). ...
... As significant plant pathogens, several Biscogniauxia species can cause severe diseases, such as charcoal canker induced by B. nothofagi, B. rosacearum, and B. uniapiculata (Nugent et al. 2005, Bahmani et al. 2021, as well as white or soft rot of plants associated with B. uniapiculatum (Lee 2000). As plant endophytes, bioactive compounds from endophytic Biscogniauxia species have demonstrated anticancer, antifungal, antimycobacterial, or antioxidant activity (Cheng et al. 2012, Sritharan et al. 2019, Sahoo et al. 2021. ...
Species of Biscogniauxia (Graphostromataceae) are known as pathogens and endophytes, distributed worldwide. In this study, we isolated two new endophytic strains of Biscogniauxia from Dicranopteris dichotoma. A new species, B. dicranopteridis, and a new host record of B. petrensis were identified based on morphology and phylogenetic analysis of four genes loci (LSU, ITS, RPB2 and β-TUB). Detailed descriptions and illustrations of the two new isolates, along with a phylogenetic tree depicting the position of the new species, are provided.
... According to Petrini [32], this would qualify them as endophytes during this latent period. Some studies have demonstrated that these species can rapidly transform from a benign endophyte to a primary pathogen [33,34]. Under stress conditions, they can swiftly infiltrate woody tissues, sometimes becoming noticeable as fungal stroma on branches and trunks [35]. ...
... B. mediterranea is typically found in association with trees affected by drought, fires and mechanical injuries [38]. Nugent et al. [34] mention water stress as a key factor predisposing trees to susceptibility to attacks by this fungus. Biscogniauxia species are recognised for inducing cankers on the bark of trees. ...
A field investigation of olive trees in Istria, Croatia, revealed branch dieback and cracked bark. Samples of diseased branches were collected from eight different locations and analysed. Additionally, meteorological data from two locations were analysed to determine if there was a connection between climatic changes and the appearance of pathogens in the region. Pathogenicity tests were conducted on olive seedlings. This study provides a description of Biscogniauxia and Sordaria species’ morphology and elucidates their phylogeny based on the internal transcribed spacer (ITS), beta-tubulin (TUB2) and translation elongation factor 1-alpha (TEF1- α) regions. This research represents the first documented occurrence of Biscogniauxia mediterranea causing charcoal disease in olive trees in Croatia. Additionally, it is the first report of Biscogniauxia nummularia (Bull.) Kuntze and Sordaria fimicola causing diseases in olive trees anywhere in the world. Furthermore, this study marks one of the initial forays into molecular investigations of these species isolated from olive trees. Considering the potential threat posed by the inherent aggressiveness of Biscogniauxia species, further research is deemed necessary to curb the development of charcoal disease.
... Biscogniauxia is a genus of fungi in the family Xylariaceae with more than 50 recognized taxa worldwide [6,7]. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites [4]. ...
... Structures of coumarin and isocoumarin(5)(6)(7)(8)(9). ...
The genus Biscogniauxia, a member of the family Xylariaceae, is distributed worldwide with more than 50 recognized taxa. Biscogniauxia species is known as a plant pathogen, typically acting as a parasite on tree bark, although certain members of this genus also function as endophytic microorganisms. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites. Currently, there are a total of 115 chemical compounds belonging to the class of secondary metabolites, and among these compounds, fatty acids have been identified. In addition, the strong pharmacological agents of this genus are (3aS,4aR,8aS,9aR)-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto [2,3-b]furan-2(3H)-one (HDFO) (antifungal), biscopyran (phytotoxic activity), reticulol (antioxidant), biscogniazaphilone A and B (antimycobacterial), and biscogniauxone (Enzyme GSK3 inhibitor). This comprehensive research contributes significantly to the potential discovery of novel drugs produced by Biscogniauxia and holds promise for future development. Importantly, it represents the first-ever review of natural products originating from the Biscogniauxia genus.
... Biscogniauxia nummularia is one of the most common endophytes and latent pathogens of woody tissues of European beech (Chapela and Boddy, 1988;Chapela, 1989). The results of our pathogenicity tests revealed the ability of Bi. nummularia to cause necrosis on European beech in planta, which fits the results of Nugent et al. (2005) and observations in nature . The inoculated saplings supplied with sufficient water exhibited necrosis, even though water deficit can be a main factor to predispose the plant to disease (Boyer, 1995). ...
... The inoculated saplings supplied with sufficient water exhibited necrosis, even though water deficit can be a main factor to predispose the plant to disease (Boyer, 1995). Derived from healthy functional beech xylem tissue, Bi. nummularia can take advantage of altered host physiology and cause strip-cankers, bark blisters, bark ruptures, and wood-decay on European beech in nature (Hendry et al., 1998;Nugent et al., 2005). The growth and virulence of xylariaceous wood-decay fungi is favored by warm temperatures (Hendry et al., 2002) and prolonged summer drought (Luchi et al., 2015). ...
Filamentous fungi associated with woody tissues of European Beech (Fagus sylvatica) and isolated from diseased trees and healthy trees were examined in relation to their impact on tree health. To this end, classical culture-based isolation methods, in planta inoculations and fungal identification using ITS-barcode and morphological characters were used. Stem endophytes of healthy beech saplings collected in German forests were isolated to determine endophyte communities in woody stem tissues. Pathogenicity tests were performed on living potted beech saplings using twelve selected fungal pathogens and wood inhabiting fungi (Hypocreales, Botryosphaeriales, and Xylariales) originating mainly from European beech with symptoms of the complex disease Vitality loss, or from bark necroses, or known to be common endophytes of beech. The impact of these ascomycetous fungi with respect to tree health was discussed. The potential influences of endophytic fungi of beech and of test conditions are discussed in relation to the success of inoculation. All tested fungal strains except for Neonectria ditissima were able to establish themselves post inoculation in the beech stems and caused necroses when there was sufficient water, but at different severities. Under the experimental conditions, Botryosphaeria corticola was shown to be the most virulent tested latent pathogen against F. sylvatica. In the context of climate change and global warming, the tested Botryosphaeriaceae are able to play a primary role in the disease progress of Vitality loss of Beech. The key role of Neonectria coccinea in causing bark necroses and the loss of vitality in beech was confirmed because the tested strain induced large lesions on the beech saplings.
... Biscogniauxia mediterranea is an ascomycete fungus, belonging to Xylariaceae family (Vannini et al., 1999), responsible for the charcoal disease on a wide range of hosts especially the genus Quercus and usually associated with oak decline (Nugent et al., 2005). As opportunistic pathogen, it is unable to cause disease on healthy hosts because it is recognized as an endophyte living asymptomatically for a long time within host tissues (Mazzaglia et al., 2001). ...
... In cork oak, the occurrence of B. mediterranea was firstly reported in Portugal in 1930 (Santos, 2003). Later on, it was reported on many other woody hosts like Quercus ilex in Spain (Collado et al., 2001), Q. cerris and Q. pubescens in Croatia (Diminić et al., 2019) Erica multiflora in Tunisia (Yangui et al., 2019a), and some Eucalyptus species in Portugal (Nugent et al., 2005). ...
Cork oak decline and mortality are increasingly prevalent in the Mediterranean basin. This require particular attention due to the great economic value of this plant species. Biscogniauxia mediterranea is one of the most common pathogens highly associated to cork oak decline. However, documentation on its incidence is still scarce, especially in Tunisia. In this context, our research aimed at detecting its presence in Tunisian natural cork oak forests and assessing factors influencing its occurrence. Investigations were carried out in six forests in northwestern Tunisia. Dendrometric parameters of trees, ecological factors (rainfall, temperature, and altitude), and the presence of B. mediterranea as pathogen were determined. The endophytic presence of this fungus was also established. It was detected in all investigated forests, with significantly different frequencies, and was reported to be related to the dendrometric structure of the cork oak trees. On the other hand, the presence of B. mediterranea as pathogen was only detected in Ain Beya and Ain Sarouia forests. It was very limited with 4% of trees per site showing the disease signs. In conclusion, measures to prevent the dispersal of B. mediterranea throughout other cork oak forests shall be implemented in order to conserve such valuable forest resources.
... Kuntze is a member of the Xylariaceae, a family that includes saprobes, pathogens and endophytes (Petrini and Petrini 1985;Ju et al. 1998). This fungus occurs as an endophyte in several species belonging to different plant families, but seems to produce sexual reproductive structures exclusively on beech (Fagus sp.) (Petrini and Petrini 1985;Nugent et al. 2005). These fructifications are dark stromata that develop on dead and living beech branches and trunks (Fig. 1a) (Hendry et al. 1998;Ju et al. 1998). ...
... Although B. nummularia is mainly saprotrophic, it can behave as a pathogen under some circumstances, being able to form elongated cankers that can kill branches, trunks and trees. This disease, called strip cankering, is associated with declines observed in European beech (Fagus sylvatica) woods, following episodes of drought stress (Hendry et al. 1998;Granata and Sidoti 2004;Nugent et al. 2005). ...
Biscogniauxia nummularia is known for its association with beech (Fagus sylvatica), on which it occurs as a saprotroph and a pathogen causing strip cankers following water stress. This fungus has also been reported as a dominant endophytic species in plants of the sedge Carex brevicollis growing in the understory of beech forests and adjacent grasslands in Sierra de Urbasa (Navarre, Spain). In this area, stromata of B. nummularia were observed in dead and living wood of beech trees at several locations where plants of C. brevicollis also contained the fungus as an endophyte. Pure cultures obtained from stromata of B. nummularia on F. sylvatica trees were compared to endophytic isolates from symptomless C. brevicollis. Culture morphology and micromorphology as well as rDNA sequences of the internal transcribed spacer (ITS) regions were identical, suggesting that B. nummularia from beech can also live endophytically in C. brevicollis. It is unknown whether the endophytic strains of Carex might have a role as an inoculum source for the infection of beech trees, or whether they represent a dead end in the life cycle of the fungus.
... Several compounds derived from fungi that exhibited α-glucosidase inhibitory activity have been reported such as alkaloids, p-terphenyls, depsidones, isocoumarins, quinones, depsipeptides, butanolide polyketides, and meroterpenoids [6]. The Biscogniauxia genus belongs to the Graphostromataceae family, of which there are more than fifty accepted taxa worldwide [7]. There have been around twenty reports on their secondary metabolites and biological activities with various classes of bioactive compounds having been discovered. ...
The search for a potent α-glucosidase inhibitor from the fungus Biscogniauxia capnodes SWUF15-40 yielded eighteen compounds. A comprehensive analysis from NMR and MS data revealed three new α-pyrones, biscogniapyrones A–C (1–3), two new isocoumarins (5 and 6), and thirteen known compounds. The configurations were assigned from calculated 13C NMR chemical shifts and ECD spectra, together with 1H NMR analysis of Mosher esters. Several compounds exhibited effective inhibitory activity against α-glucosidase with IC50 values in the range of 0.041–0.257 mM, which are lower than the positive control, acarbose (IC50 0.713 mM). The proposed non-competitive mode of inhibition was deduced from Lineweaver–Burk plots together with Km and Vmax values. In silico dockings of the strongest inhibitor, compound 3 were studied. Three out of the five determined allosteric sites of the enzyme model were favorable, with closed free binding energies of roughly − 4.00 kcal/mol. The binding interactions observed between 3 and amino acids in the pocket sites were hydrogen bonding and hydrophobic interactions. These findings, therefore, provide opportunities for drug development processes to be carried out.
... 44,45 As an example, Biscogniauxia mediterranea Kuntze, usually seen as harmless endophytic fungi, may cause charcoal disease on drought-stressed oaks (Quercus spp.). 46,47 Overall, these changes compromise the ability of greenspace to provide cooling, air purification, and other ecosystem functions. ...
An increasing proportion of the world’s population lives in urban settings that have limited greenspace. Urbanization puts pressure on existing greenspace and reduces its access. Climate impacts, including increased temperature and extreme weather events, challenge the maintenance of urban vegetation, reducing its ecosystem services and benefits for human health. Although urban greenspace has been positively associated with numerous health indicators, the evidence for allergies and respiratory health is much less clear and mixed. To address these uncertainties, a workshop with 20 global participants was held in Munich, Germany, in May 2024, focusing on the impact of greenspace-related co-exposures on allergies and respiratory health. This narrative review captures key insights from the workshop, including the roles of urban greenspace in (1) climate change mitigation, (2) interactions with pollen, and (3) emissions of biogenic volatile organic compounds and their byproducts, such as ozone. Additionally, it presents research and stakeholder recommendations from the workshop. Future studies that integrate advanced greenspace exposure assessments and consider the interplay of greenspace with pollen and biogenic volatile organic compounds, along with their relevant byproducts are needed. Increased public awareness and policy actions will also be essential for developing urban greenspace that maximizes health benefits, minimizes risks, and ensures resilience amid a changing climate and rapid urbanization.
... Their secondary metabolites can also regulate the growth of the plants they colonize and activate their defense response [37]. The Biscogniauxia fungi is present in healthy trees as an endophyte but can become invasive under drought conditions [38]. In 2012, Ming-Jenet al. identified secondary metabolites in Biscognauxia with antimycobacterial capacity [39], while Silva-Hughes et al. evidenced the presence of a compound with moderate antifungal activity against the phytopathogenic fungus Phomopsis obscurans [40]. ...
The taxane molecules extracted from the bark of trees from the Taxus genus demonstrate anticancer activity and are the main components of the drug paclitaxel. Even though a great deal of research has been carried out to produce them synthetically, this manufacturing is still dependent on Taxus cell culture. Furthermore, these processes are not suitable for steady taxane production. Therefore, the search for alternative sources of taxane production has generated growing interest amongst the scientific community. The use of endophytic fungi for the obtention of taxane constitutes an attractive alternative. Here, we present an analysis of the taxane production of several microorganisms through LC–QTOF MS/MS. We isolated 21 endophytic fungus strains, identified through sequencing of their internal transcribed spacer region (ITS). The phylogenetic analysis showed the presence of 11 different Fungus genera, namely Aspergillus, Trichoderma, Neurospora, Penicillium, Curvularia, Arcopilus, Biscogniauxia, Hypoxylon, Sordaria, Xylariales, and Gelasinospora. These fungi have been previously described to synthetize distinct metabolites of medical interest, hence supporting the study of their potential taxane production. Here, we report the production of taxadiene by some of these fungi, namely Aspergillus sp. (1.35 μg/L), TgO (0.7 μg/L), Trichoderma harzianum (0.13 μg/L), and Hypoxylon sp. (0.3 μg/L). Furthermore, we also detected the production of baccatin III, a crucial precursor component of the drug paclitaxel. This is the first report of taxane production by fungi phylogenetically related to the Arcopilus and Endoxyla genera.
... Fagus sylvatica L. (Nugent et al., 2005) on which it can cause stripcankers and wood decay (Granata & Sidoti, 2004). Biscogniauxia nummularia has also been reported from conifers such as pine, fir and Douglas fir (Bartnik et al., 2021;Bußkamp et al., 2020;Patejuk et al., 2022;Petrini, 1985;Pusz et al., 2020). ...
Dieback of dwarf pine scrub ( Pinus mugo subsp. mugo ) shoots can limit the growth of this species in subalpine areas of the Carpathian Mountains. In July 2023, extensive shoot decline was observed in P. mugo patches in the West Tatra Mountains in southern Poland. Symptomatic shoots showed shoot tip dieback and red‐brown needle discoloration. Internal symptoms included dark discoloration of the pith parenchyma and necrotic lesions in shoot periderms. In this study, we described the symptoms of P. mugo shoot dieback and surveyed the culturable fungi from asymptomatic and symptomatic P. mugo shoots, as well as the bases of needles growing from shoots. In addition, we conducted phylogenetic analyses to distinguish between potential cryptic species of Sydowia polyspora . The dwarf pine scrub shoots and needles were sampled from four patches in the Polish Tatra Mountains. In total, 128 distinct taxa were identified. Ascomycota was dominant, representing 96.6% of the isolates. Among the taxa identified, Sydowia polyspora crypt. sp. I, Lachnellula calyciformis , Mollisia sp. 8, Tympanis sp., Epicoccum mezzettii , E. nigrum , Infundichalara sp., Lophium mytilinum , Cytospora sp., Soosiella sp., Cladosporium westerdijkiae and Hendersonia pinicola were most frequently isolated. In most cases, tissue type and sample site significantly affected the abundance and composition of colonizing fungi. Only S. polyspora was found consistently in all sample types, suggesting that this fungus may be responsible for the shoot dieback of P. mugo . Phylogenetic analyses demonstrated that S. polyspora should be treated as a species complex containing at least four cryptic species (referred to as groups I–IV), that are highly host‐specific to different conifer species. We also found several other well‐known pathogens, namely Allantophomopsis pseudotsugae , Botrytis cinerea , Cytospora sp., Fusarium sp., Sirococcus conigenus and Tympanis sp., which may cause considerable damage to Pinus spp. shoots. Among them, only Cytospora sp., and Tympanis sp. were found often. This is the first comprehensive survey of the fungi associated with extensive shoot dieback of P. mugo in the Carpathian Mountains, and this research led to the discovery of numerous new fungal species associated with P. mugo .
... Biscogniauxia is globally distributed, usually acting as an ubiquitous wood decomposer and a common endophyte [69]. There is substantial evidence that Biscogniauxia species exist as endophytes within healthy trees and later become pathogenic to plants when adverse stress occurs [70,73]. Although Biscogniauxia has been characterized as an endophytic fungus, evidence from several studies indicate that these endophytes, akin to pathogenic bacteria, possess intrinsic virulence factors and exhibit prolonged latent periods. ...
In June 2020, needle blight symptoms on Pinus thunbergii were discovered in Bazhong City, Sichuan Province, China. Fungal isolates were obtained from the pine needles of P. thunbergii. After examining morphological characteristics and conducting multi-locus (ITS, ACT, TUB2 and RPB2) phylogenetic analyses, the isolates SC1–SC5 were determined to be a new species, Biscogniauxia sinensis. Genealogical Concordance Phylogenetic Species Recognition with a pairwise homoplasy index test was used to further verify the results of the phylogenetic analyses. The morphology and phylogenetic relationships between this new species and other related Biscogniauxia species were discussed. To our knowledge, this is also the first report of Biscogniauxia sinensis associated with pine needle blight on P. thunbergii in China. The needle damage of P. thunbergii associated with Biscogniauxia sinensis will detrimentally affect the carbon absorption and photosynthetic efficiency of P. thunbergii, further reduce the absorption of nutrients by Japanese black pine and may lead to the imbalance of pine forest conditions, which will have a negative impact on the forest ecological system.
... Taxa identified with certainty to species level were subjected to a literature search for reported fungus-host associations with Acer or A. pseudoplatanus. Biscogniauxia mediterranea has been reported from Acer rubrum L., Acer sp. or Acer spp., however, A. pseudoplatanus has not been mentioned specifically (Ju et al. 1998;Nugent et al. 2005;Ragazzi et al. 2011). Coniochaeta velutina has been reported from different woody host plants worldwide (Damm et al. 2010;Johnová 2009;Shamoun and Sieber 2000), including A. saccharum in Canada (Basham et al. 1969). ...
The causative agent of sooty bark disease, Cryptostroma corticale , has, for some years, caused increased damage to maples ( Acer spp.) in Germany and throughout Europe. It has been stated that this pathogen can occur latently in Acer . In this study, the composition of endophytic fungi of woody stem tissues of sycamore ( Acer pseudoplatanus ) saplings were analysed in order to investigate whether C. corticale is present in young, visually healthy maple trees from natural regeneration. The most abundant taxa of the 30 isolated endophytes were Diaporthe cf. rudis and Petrakia irregularis . An association of five fungal species ( Biscogniauxia mediterranea , Coniochaeta velutina , Gibellulopsis catenata , Neocucurbitaria quercina , Tangerinosporium thalitricola ) with A. pseudoplatanus was reported for the first time. Cryptostroma corticale was not present in the juvenile sycamore stems. Furthermore, its pathogenicity was studied in comparison to other pathogens associated with A. pseudoplatanus , namely Diplodia mutila , Dothiorella sp., Nectria cinnabarina , Neonectria coccinea , Neonectria punicea and Stegonsporium pyriforme . The longest necroses were induced by C. corticale followed by N. coccinea . In a trial with a C. corticale spore suspension sprayed directly on stem bark, the fungus could be re-isolated from woody tissue, however necroses were evoked only when the bark was wounded prior to infection. The results from the experiments presented here function as additional evidence for the ability of C. corticale to establish endophytically within the host and, in particular, for the ability of the fungus to establish a successful infection/entrance through intact bark.
... Here we will discuss the main factors that are directly involved. We find B. mediterranea, is an opportunistic fungus of weakness on which it causes the disease of charcoal canker , known for its pathogenicity towards many forest species, in particular of the genus Quercus [77], of which it causes the decline in North Africa [78]. It is the agent of the sooty stroma of oak trunks and branches that has played an important role in the decline of oaks throughout the Mediterranean region [79]. ...
Description of the subject: In recent decades, cork oak forests have experienced serious health problems, including decline caused by pathogenic fungi, leading to the instability and degradation of this important forest resource. Due to the great ecological and economic importance of cork oak forests and given the lack of information on the etiology on this degradation. Objectives: The study are aimed to: i) study the health status of the stands in each region and ii) assess the infection of the cork oak by the endophyte Biscogniauxia mediterranea, an agent of charcoal canker associated with cork oak decline. Methods : Sampling was carried out in 2017 on two forests in western Algeria: Djebel Saadia (Relizane) and Hafir (Tlemcen), which was the subject of various surveys distributed according to station surveys relating to the station data, dendrometric, tree condition and management data were considered. Results :There obtained from the point of view of circumferences and heights, showed that the trees affected by B. mediterranea canker in the forest of Hafir contains a threshold of 80% form the 2nd class of circumference (Ø between 70 and 109 cm) and the other classes are less attacked and belong to the two classes 2 (H: 6-7 m) and 3 (H: 7-10 m) of heights, , whereas in the forest of Djebel Saadia, the infected subjects belong to class 1 whose circumference is of the order of Ø < 70 cm and class 1 whose height is of the order of H < 6 m. For each individual forest, a statistical analysis was performed to relate the detection of B. mediterranea to the quantitative data of dendrometric parameters, including height and circumference, plus calculation of infection rate, which shows no difference between the two study sites. Conclusion: This original study, reports the diagnosis health status and forest of the cork oak in two forests such as Djebel-Saadia and Hafir to characterize them, the evaluate and highlight the involvement of the pathogen B. mediterennea in the observed decline from the various parameters related to the state of the trunks by meticulous observations and notations reveal the presence of the fungus. Résumé Description du sujet : Au cours des dernières décennies, les forêts de chêne-liège ont connu de sérieux problèmes sanitaires dont le dépérissement causé par les champignons pathogènes conduisant à leur instabilité et leur dégradation de cette importante ressource forestière. En raison de la grande importance écologique et économique des subéraies et vu le manque des informations sur l'étiologie de cette dégradation; les subéraies de la partie d'Algérie occidentale n'échappent pas à ce constat. Objectifs : de l'étude vise à : i) étudier l'état sanitaire des peuplements de chaque région et ii) apprécier l'infection du chêne-liège par l'endophyte Biscogniauxia mediterranea agent du charbon de la mère associé aux dépérissements du chêne-liège. Méthodes : L'échantillonnage était réalisée en 2017 sur deux forêts: Djebel Saadia (Relizane) et Hafir (Tlemcen), qui a été l'objet de divers relevés repartis selon les relevés stationnels relatifs à la station, les relevés dendrométriques, l'état d'arbre et l'état d'exploitation. Résultats : Obtenus de point de vue circonférences et hauteurs, ont montré que les arbres atteints par le chancre à Biscogniauxia, dans la forêt de Hafir contient un seuil de 80% forment la 2 ème classe de circonférence (Ø entre 70 et 109 cm) et les autres classes sont moins attaqués et appartiennent au deux classes 2 (H : 6-7 m) et 3 (H : 7-10 m) de hauteurs, , alors que dans la foret de Djebel Saadia, les sujets infectés appartiennent à la classe 1 dont la circonférence est de l'ordre de Ø < 70 cm et la classe 1 dont la hauteur est de l'ordre de H< 6m. Chaque forêt individuelle, une analyse statistique a été effectués pour relier la détection de B. mediterranea aux données quantitatives des paramètres dendrométriques, dont la hauteur et la circonférence, plus le calcul du taux d'infection, qui ne montre aucune différence entre les deux sites d'étude. Conclusion : Cette originale étude, a permis de réaliser le diagnostic sanitaire du chêne-liège dans deux forêts telles que Djebel-Saadia et Hafir pour les caractériser, les évaluer et mettre en évidence l'implication du pathogène B. mediterennea dans le dépérissement observé en se basant sur les différents paramètres liés à l'état des troncs.
... The pleosporalean fungus Didymella macrostroma is presumed to have an endophytic life stage as well, since many other fungi in the Pleosporales have endophytic life stages . Biscogniauxia nummularia is a known and widespread multi-host endophyte isolated from several different tree species (Petrini-Klieber 1985;Chapela and Boddy 1988;Chapela 1989;Nugent et al. 2005;Bußkamp et al. 2020) belonging to the Xylariales as well, and very common on beech trees (Chapela and Boddy 1988;Chapela 1989). To the authors' knowledge, this fungus has not been reported from Acer before. ...
From 2018 to 2020, Germany experienced periods of exceptional weather conditions. Extremely high summer temperatures and precipitation deficits induced stress and mortality in forest trees. Acer pseudoplatanus (sycamore) was one of the affected tree species. Symptoms of sooty bark disease (SBD) and severe damage of entire stands, both caused by the fungal species Cryptostroma corticale , were reported more frequently. To explore the non-symptomatic distribution of C. corticale , wood cores from visibly healthy sycamore stems were sampled and all outgrowing fungi were identified and recorded. In total, 50 trees, aged 30–65 years, were sampled at five different forest stands, from which 91 endophytic filamentous morphotypes could be isolated. The fungal endophytic community in the woody tissue of the sycamore trees varied greatly at the different sites and between the trees. The number of isolated morphotypes at the different sites ranged from 13 to 44 and no morphotype was found at all sites. At 1.20-m stem height, 3.3 fungi could be isolated from woody tissue per tree on average. The most abundant species isolated from visibly healthy sycamore in regard to both occurrence at the studied sites and continuity was C. corticale. It was recorded at four of the studied forest stands, from 26% of all studied sycamore trees, and had a frequency of 7.85% relative to the 293 isolated filamentous strains that were isolated. The second most abundant species was Xylaria longipes followed by Lopadostoma turgidum . In this study clear evidence for the endophytic lifestyle of C. corticale is presented which thus appears to be spread further than expected based on visible SBD symptoms.
... Whalley and Laessoe, B. nummularia (Bull.) Kuntze and B. nothofagi Whalley, Laessoe, and Kile, have been reported to cause cankers in other tree species, such as Nothofagus, Fagus, and Eucalyptus (Nugent et al., 2005). ...
Charcoal canker of oak, which has recently increased in southern Iran, could pose a serious threat to the entire forest ecosystem in the near future. In addition, it seems that climate change and its consequences, such as drought in the southern regions of Iran, have exacerbated this phenomenon. Consequently, the objective of this study was to identify the fungal pathogens that could cause charcoal canker disease in the oak forests of South Zagros. It was also sought to find associations between changes in the occurrence/exacerbation of charcoal canker disease under non and intense drought stress in non-inoculated or inoculated Quercus brantii seedlings. In total, 120 isolates were obtained from eight oak forests located in the Zagros Mountains of Southern Iran, Kohgiluyeh & Boyer-Ahmad and Fars provinces, which were classified as Biscogniauxia mediterranea based on morphological assessment. Subsequently, molecular assay confirmed the result by phylogenetic inference of internal transcribed spacer–rDNA regions, α-actin, and β-tubulin genes. The results of the pathogenicity test showed that the response of isolates of B. mediterranea (Iran-G1 and Iran-M70) was varied in different environments for the measured necrotic lesion length. In comparison with the control moisture treatments (non-stress), the necrotic lesion length in inoculated treatments increased under intense drought stress. In general, inoculated oak seedlings’ exposure to water-deficient stress by the pathogen of B. mediterranea could affect the spread/severity of the charcoal canker disease.
... Biscogniauxia nummularia (Bull.) Kuntze (synonym: Hypoxylon nummularium Bull.) is an ascomycetous fungus belonging to the family Xylariaceaes, that induces strip-cankers on beech, commonly called charcoal canker or beech tarcrust (BTC) disease [1][2][3][4][5][6]. The symptoms of infection are visible on the host tree's bark as elongated, blackish bark lesions on the trunk and branches, and as wood decay in mature trees. ...
Biscogniauxia nummularia (Bull.) Kuntze is a fungus which induces strip-cankers on beech, commonly referred to as charcoal canker. The symptoms of infection are visible on the host tree’s bark as elongated, blackish bark lesions on the trunk and branches. Recent years have shown that, due to climate change causing local epidemics, the species is increasing its economic impact in Mediterranean regions. Until recently, B. nummularia was considered rare and uncommon in central Europe. However, in the last few years it has been noticed more often, mostly in coniferous trees, which are out of B. nummularia’s host range. A similar situation has been observed with the closely related species Biscogniauxia mediterranea (De Not.) Kuntze, which prior to 2017 had not been observed in central Europe at all. This study shows the genetic diversity of mid-European strains of Biscogniauxia spp. (based on the ITS, TEF1, TUB2 and ACT regions) and, as the first in Europe, presents a molecular investigation of this species isolated from coniferous trees. It is also the first attempt at estimating the potential impact of this pathogenic fungus on European forestry management in the close future.
... Stressed and dying Quercus trees have been found to be attacked by Biscogniauxia fungi (Bendixsen et al., 2015;Freeman et al., 2019;Nugent et al., 2005), while G. triacanthos is known to be impacted by several fungal diseases (Bedker & Wingfield, 1983;Crowe et al., 1982). ...
Structural diversity is an emerging dimension of biodiversity that accounts for size variations in organs among individuals in a community. Previous studies show significant effects of structural diversity on forest growth, but its effects on forest mortality are not known, particularly at a large scale.
To address this knowledge gap, we quantified structural diversity using stem structural diversity (SSD) based on both tree diameter and height. We obtained U.S. Forest Service Forest Inventory and Analysis (FIA) data from over 2400 plots across southcentral U.S. forests that have suffered a recent drought. Using data from multiple sampling times, we calculated SSD and compared the relative importance of SSD, species diversity, functional diversity and other stand attributes in determining tree mortalities caused by fire, insects and diseases. We also used FIRETEC, a physics‐based fire model, to test the effect of SSD on canopy consumption by fire.
Our results showed that (1) SSD was positively associated with tree mortalities caused by all three disturbances; (2) species richness was negatively associated with insect‐ and disease‐caused mortalities; (3) functional diversity was negatively associated with fire‐ and disease‐caused mortalities and (4) more phylogenetically related species had more similar mortality rates by insect and disease but not fire. Moreover, the FIRETEC model showed increasing canopy consumption by fire in stands with greater SSD.
Together, the different tree mortalities during drought associated with SSD more consistently than the other biodiversity metrics were evaluated.
Synthesis. Our results suggest that SSD could be considered in modelling forest dynamics and planning management to sustain forest health under disturbances.
... Whalley and Laessoe, B. nummularia (Bull.) Kuntze and B. nothofagi Whalley, Laessoe, and Kile, have been reported to cause cankers in other tree species, such as Nothofagus, Fagus, and Eucalyptus (Nugent et al., 2005). ...
... As pointed out by Whalley (1996) (Collado et al. 2001;Nugent 2005). It has therefore been studied more intensively than most other Xylariaceae by plant pathologists. ...
This is a habilitation thesis.
The contents have also been published in the following review:
Stadler M 2011 – Importance of secondary metabolites in the Xylariaceae as parameters for assessment of their taxonomy, phylogeny, and functional biodiversity. Current Research in Environmental & Applied Mycology 1(2), 75-133, Doi 10.5943/cream/1/2/1
... & S. Waller, nested within Biscogniauxia, are responsible for causing cankers on hardwood trees, but these are typically considered opportunistic pathogens of trees under stress (Koukol et al. 2015;U'Ren et al. 2016;Paez and Smith 2017). Although Cryptostroma and Biscogniauxia cause slightly different disease symptoms on distinct hosts (Gregory and Waller 1951;Ju et al. 1998;Ju and Rogers 2001;Nugent et al. 2005;Vasilyeva and Stephenson 2014;Raimondo et al. 2016;Paez and Smith 2017), they appear to use similar strategies for colonization, causing wilt, canker, and dieback through infection of the vascular bundles, leading to a disruption of the flow of water and nutrients (McBride and David 2009; Balbalian and Henn 2020). Although Cryptostroma corticale produces a thin layer of black stroma (pseudoparenchyma) on the surface of infected tissue (Gregory and Waller 1951), similar to what is observed on the roots of soybean colonized by X. necrophora, we do not at present have evidence that the disruption of translocation produces the symptoms observed with TRD. ...
Taproot decline (TRD) is a disease of soybean that has been reported recently from the southern United States (U.S.). Symptoms of TRD include foliar interveinal chlorosis followed by necrosis. Darkened, charcoal-colored areas of thin stromatic tissue are evident on the taproot and lateral roots along with areas of necrosis within the root and white mycelia within the pith. Upright stromata typical of Xylaria can be observed on crop debris and emerging from infested roots in fields where taproot decline is present, but these have not been determined to contain fertile perithecia. Symptomatic plant material was collected across the known range of the disease in the southern U.S., and the causal agent was isolated from roots. Four loci, ⍺-actin (ACT), β-tubulin (TUB2), the nuclear rDNA internal transcribed spacers (nrITS), and the RNA polymerase subunit II (RPB2), were sequenced from representative isolates. Both maximum likelihood and Bayesian phylogenetic analyses showed consistent clustering of representative TRD isolates in a highly supported clade within the Xylaria arbuscula species complex in the "HY" clade of the family Xylariaceae, distinct from any previously described taxa. In order to understand the origin of this pathogen, we sequenced herbarium specimens previously determined to be "Xylaria arbuscula" based on morphology and xylariaceous endophytes collected in the southern U.S. Some historical specimens from U.S. herbaria collected in the southern region as saprophytes as well as a single specimen from Martinique clustered within the "TRD" clade in phylogenetic analyses, suggesting a possible shift in lifestyle. The remaining specimens that clustered within the family Xylariaceae, but outside of the "TRD" clade, are reported. Both morphological evidence and molecular evidence indicate that the TRD pathogen is a novel species, which is described as Xylaria necrophora.
... (Troncoso-Rojas and Tiznado-Hern andez, 2014), Biscogniauxia spp. (Nugent et al., 2005), Botrytis spp. (Williamson et al., 2007) and Stemphylium spp. ...
The factors shaping endophytic fungal assemblages in reproductive organs have been less evaluated than in vegetative organs. Here, the temporal dynamics of fungal endophytes in inflorescences and fruits of olive tree cultivars with contrasting anthracnose susceptibilities was assessed, starting before flowers open until fruit ripening. Fungal diversity assessed by rRNA sequencing of cultivable isolates revealed a higher richness and abundance of endophytes in inflorescences than in fruits. Endophytes from Sor-dariomycetes were dominant in inflorescences, while in fruits they were from Dothideomycetes. The overall assemblages of inflorescences and fruits were shaped mainly by the plant organ, followed by the phenological stage and lastly, by the plant cultivar. The importance of cultivar as a shaping factor varied according to the plant organ, being only significant in inflorescence-associated endophytes. A set of fungal taxa were positively associated with a particular cultivar and phenological stage, likely contributing to the plant anthracnose resistance.
... They have been isolated from roots of Bulbophyllum exiguum orchids (Orchidaceae) in Australia and various tissues of oaks from Europe and the USA (Collado et al. 2001;Mazzaglia et al. 2001;Granata and Sidoti 2004;Luchi et al. 2005;Calvert 2017). They are known to be latent invaders of angiosperm forest trees causing disease under stress conditions (Raimondo et al. 2016), such as Biscogniauxia mediterranea which causes charcoal canker of cork oak and spreads in areas of forest affected by greater intensity of drought (Nugent et al. 2005;Henriques et al. 2016). Proliferation of B. mediterranea was found to be favored by a decrease in host water potential (Vannini et al. 2009). ...
Biscogniauxia belongs to the family Graphostromataceae, and species have been found mainly as pathogens in dicotyledonous plants worldwide. Two endophytic strains, Biscogniauxia dendrobii sp. nov. and B. petrensis were isolated from Dendrobium aphyllum and D. harveyanum sampled from southwestern China and northern Thailand respectively. The conidiophores and conidia were used for morphological characteristic estimation. The maximum likelihood and Bayesian analysis with ITS, TUB2, RPB2 and LSU sequence data were combined for phylogenctic identification. Biscogniauxia dendrobii sp. nov. is introduced based on the large discrepancy of both sequences (5.2%) and size of conidia. Another known species B. petrensis is also illustrated and described in this study to facilitate species identification on D. harveyanum. The ethyl acetate crude extract of the isolate B. petrensis showed moderate and strong cytotoxic activity against A549 and K562 using the CCK8 assay (IC50 of it 13.5 and 3.5 ug/ml respectively). This is the first report of endophytic Biscogniauxia in Dendrobium species and of their cytotoxicity to A549 and K562, all of which enhances the current knowledge on the genus Biscogniauxia.
... K. Koch trees in Iran (Mirabolfathy et al. 2011;Mirabolfathy 2013). The fungus has also been found causing charcoal disease on forest trees in other countries Nugent et al. 2005). According to Mohammadi et al. (2014), four species of Togniniaceae, namely Phaeoacremonium parasiticum (Ajello, Georg & C.J.K. Wang) W. Gams, Crous & M.J. Wingf., P. minimum Tul. and C. Tul., P. iranianum L. Mostert Hashemi and Mohammadi (2016), some members of Togniniaceae, Botryosphaeriaceae and Diatrypaceae were isolated from willow and poplar trees in Iran. ...
From 2012 to 2015, several field surveys were conducted throughout forest areas in the north of Iran in order to determine the occurrence of species of Botryosphaeriaceae on forest trees. Fungal isolations were made from symptomatic branches of 20 tree genera including Acer, Alnus, Carpinus, Crataegus, Cupressus, Cydonia, Diospyros, Fagus, Fraxinus, Gleditsia, Mespilus, Parrotia, Pinus, Populus, Prunus, Pterocarya, Punica, Quercus, Ulmus and Zelkova, as well as fruiting bodies formed on the surface of woody debris. Morphological identification along with molecular analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the nuclear ribosomal DNA (rDNA) and a partial sequence of translation elongation factor 1-α (tef-1α) gene showed that at least nine species of Botryosphaeriaceae occur on forest trees in the north of Iran. These include Dothiorella sarmentorum, Dothiorella plurivora, Neofusicoccum parvum, Botryosphaeria dothidea, Neoscytalidium novaehollandiae, Diplodia seriata, Diplodia sapinea, Lasiodiplodia mahajangana and Diplodia intermedia. Pathogenicity tests were conducted for selected isolates from each species on six tree species (Mespilus germanica, Punica granatum, Parrotia persica, Alnus glutinosa, Quercus castaneifolia and Pterocarya fraxinifolia) under field conditions. Results of the pathogenicity tests showed a variation in lesion lengths (virulence) and re-isolation frequencies of inoculated species on branches of trees, Neoscytalidium novaehollandiae, B. dothidea and D. intermedia being the most virulence species. Based on host plant species, the majority of Botryosphaeriaceae species are new records. This is the first comprehensive study on the species identification, distribution and pathogenicity of Botryosphaeriaceae on forest trees in Iran. This is also the first report of L. mahajangana in this country.
... These fungi release enzymes that hasten the degradation process of cellulose (Azevedo et al. 2000). Possibly, these endophytic fungi settle in fresh leaves waiting for their senescence (Davis et al. 2003;Nugent et al. 2005). This strategy would provide an advantage in competition with other saprophytes, since these fungi are present inside the plant before leaf abscission (Petrini et al. 1995;Davis et al. 2003). ...
The tropics are known for their high diversity of plants, animals, and biotic interactions, but the role of the speciose endophytic fungi in these interactions has been mostly neglected. We report a unique interaction among plant sex, bees, and endophytes on the dioecious shrub, Baccharis dracunculifolia (Asteraceae). We assessed whether there was an association between resin collection by bees and fungal endophytes considering the host plant sex. We hypothesized that resin collection by the Africanized honey bee, Apis mellifera L. (Apidae) could favor the entry of endophytes in B. dracunculifolia. Specifically, we tested the hypotheses that (1) bees damage the leaf buds of female and male plant at different proportions; (2) damage on leaf buds increases the richness of endophytic fungi; (3) endophyte richness differs between female and male plants; and (4) in vitro growth of endophytes depends on the sex of the plant individual from which the resin was extracted. Endophyte richness and proportion of leaf bud damage did not vary between the plant sexes. However, species similarity of endophytes between female and male plants was 0.33. Undamaged leaf buds did not show culturable endophytes, with all fungi exclusively found in damaged leaf buds. Endophyte composition changed with the plant sex. The endophytes exclusively found in female plants did not develop in the presence of male resin extract. These findings highlight that resin collection by A. mellifera for propolis production favors the entry of endophytic fungi in B. dracunculifolia. Additionally, endophyte composition and growth are influenced by plant sex.
... The real distribution of the species may be much wider, since it lives as an endophyte in otherwise symptom-free oaks (Luchi et al. 2005). In fact, the strategy of "latent invaders" could be more widespread within the genus (Nugent et al. 2005), because many xylariaceous fungi have been detected as endophytes (Petrini & Petrini 1985, Whalley 1996. Similarly to B. mediterranea, also other species of the genus Biscogniauxia have been associated with charcoal disease (Raimondo et al. 2016) or decline of their hosts, especially on the edge of the natural occurrence of these hosts (Granata & Sidoti 2004). ...
Zíbarová L., Kout J. (2017): Xylariaceous pyrenomycetes from Bohemia: species of Biscogniauxia and Hypoxylon new to the Czech Republic, and notes on other rare species. – Czech Mycol. 69(1): 77–108. Two species of pyrenomycetes, Biscogniauxia mediterranea and Hypoxylon fuscoides, are reported from the Czech Republic for the first time. Descriptions of both species, based on the authors' collections, are provided together with notes on their distribution and ecology in the Czech Republic and Europe. Additionally new records and short discussions regarding 20 other less common taxa of pyrenomycetes of the genera Biscogniauxia, Euepixylon, Hypoxylon and Nemania (traditionally placed in Xylariaceae) in Bohemia, Czech Republic, are supplied, and recommendations for a future version of the Czech Red list of macromycetes are given.
... In addition, it is well known that there is a direct correlation between the pathogenicity of the charcoal disease and oak leaf water potential. In fact, the shift from the latent to the pathogenic phase in B. mediterranea on Quercus species is driven by a decrease in the water potential of host tissues under drought stress (Linaldeddu et al., 2005(Linaldeddu et al., , 2011Nugent, Sihanonth, Thienhirun, & Whalley, 2005;Vannini et al., 2009). In this respect, B. mediterranea spread at a high rate when water potential is reduced (Capretti & Battisti, 2007;Linaldeddu et al., 2011;Vannini et al., 2009). ...
... N. cunninghamii stem rot and defect are more prevalent in sites of poor fertility that are sub-optimal and potentially stressful for N. cunninghamii (Read, 1995), resulting in higher rates of mortality from secondary pathogens. For example, Biscogniauxia nothofagi is ubiquitous in N. cunninghamii (Whalley et al., 1990) appearing to live saprophytically as endophytes in healthy wood that switches to a pathogenic mode when trees are water stressed (Nugent et al., 2005). This is consistent with observations that the soundest N. cunninghamii generally occurs on fertile sites (Hickey, 1993;Walker and Candy, 1983). ...
As Tasmania's wet forests transition from mixed forest (eucalypt overstory with a rainforest understory) to rainforest they can be expected to lose more than half their total (live + dead, standing + downed) bole wood volume and biomass. On average rainforest sites contained 205 Mg C ha À1 , or 708 m 3 ha À1 less wood (live + dead, standing + downed) than mixed forests. This occurs as smaller dimension rainforest trees replace the larger eucalypts. On the fertile study sites, the largest rainforest trees were 20 m shorter and 113 cm smaller in breast height diameter than the mature eucalypts in mixed forests. Tasmanian wet forests do not attain the highest site level C-stocks possible in late succession, as is expected for many other forests. Rather, the maxima is attained for a short period several centuries after disturbance and regeneration of a eucalypt cohort. Hence, the maintenance of the highest C-density stands in the landscape , and potentially that largest landscape level C-stocks among Tasmania's wet forests ironically requires the periodic killing of all, or part, of the large C-dense eucalypt overstory by intense wildfire to allow these large eucalypts to regenerate and persist on these sites. This creates challenges when mod-eling forest carbon in Tasmanian wet forests, as not only is the area of forest that has progressed sufficiently toward rainforest to be emitting C is unknown, but the rate of C emission and the amount that will be lost over time across the various site fertility types is also unknown. Certainly, setting aside Tasmanian wet eucalypt forest to store C will not deliver the usual long term C accumulation benefits common to forests elsewhere. Maximizing landscape level C-stocks is likely to require periodic disturbance to maintain the C-dense eucalypts in the landscape. Crown
... N. cunninghamii stem rot and defect are more prevalent in sites of poor fertility that are sub-optimal and potentially stressful for N. cunninghamii (Read, 1995), resulting in higher rates of mortality from secondary pathogens. For example, Biscogniauxia nothofagi is ubiquitous in N. cunninghamii (Whalley et al., 1990) appearing to live saprophytically as endophytes in healthy wood that switches to a pathogenic mode when trees are water stressed (Nugent et al., 2005). This is consistent with observations that the soundest N. cunninghamii generally occurs on fertile sites (Hickey, 1993;Walker and Candy, 1983). ...
As Tasmania’s wet forests transition from mixed forest (eucalypt overstory with a rainforest understory) to rainforest they can be expected to lose more than half their total (live + dead, standing + downed) bole wood volume and biomass. On average rainforest sites contained 205 Mg C ha⁻¹, or 708 m³ ha⁻¹ less wood (live + dead, standing + downed) than mixed forests. This occurs as smaller dimension rainforest trees replace the larger eucalypts. On the fertile study sites, the largest rainforest trees were 20 m shorter and 113 cm smaller in breast height diameter than the mature eucalypts in mixed forests. Tasmanian wet forests do not attain the highest site level C-stocks possible in late succession, as is expected for many other forests. Rather, the maxima is attained for a short period several centuries after disturbance and regeneration of a eucalypt cohort. Hence, the maintenance of the highest C-density stands in the landscape, and potentially that largest landscape level C-stocks among Tasmania’s wet forests ironically requires the periodic killing of all, or part, of the large C-dense eucalypt overstory by intense wildfire to allow these large eucalypts to regenerate and persist on these sites. This creates challenges when modeling forest carbon in Tasmanian wet forests, as not only is the area of forest that has progressed sufficiently toward rainforest to be emitting C is unknown, but the rate of C emission and the amount that will be lost over time across the various site fertility types is also unknown. Certainly, setting aside Tasmanian wet eucalypt forest to store C will not deliver the usual long term C accumulation benefits common to forests elsewhere. Maximizing landscape level C-stocks is likely to require periodic disturbance to maintain the C-dense eucalypts in the landscape.
... . (Nugent et al. 2005) اﺳـﻠﻮوﻧﯽ و (Helander et al. 2007 (Ju et al. 1998, Manion and Griffin 1986, San Martin and Rogers, 1993 (Spooner 1986) . ...
... In fact, even if neutral or symbiotic relationships represent the most common biotic interactions established between endophytic fungi and trees, several studies testified that particular environmental conditions might promote the pathogen behavior of the endophytic fungi (KOWALSKI, 1991;LUISI et al. 1995;VANNINI et al., 1996;VANNINI, 1998;ANSELMI et al., 2000;RAGAZZI, 2004). In particular, endophytic fungi are considered by several authors highly pathogenic towards trees afflicted by water stress, so that they may be used as bio-indicator of water stress in forest stands (NUGENT et al., 2005). Among fungi causing rots, the presence of Armillaria sp. ...
The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi). A total of 81 sampling areas were investigated, 54 in oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling area was expressed with a synthetic index namely phytosanitary class (PC). Oak stands showed severe symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline. On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore, twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks.
... In fact, even if neutral or symbiotic relationships represent the most common biotic interactions established between endophytic fungi and trees, several studies testified that particular environmental conditions might promote the pathogen behavior of the endophytic fungi (KOWALSKI, 1991;LUISI et al. 1995;VANNINI et al., 1996;VANNINI, 1998;ANSELMI et al., 2000;RAGAZZI, 2004). In particular, endophytic fungi are considered by several authors highly pathogenic towards trees afflicted by water stress, so that they may be used as bio-indicator of water stress in forest stands (NUGENT et al., 2005). Among fungi causing rots, the presence of Armillaria sp. ...
The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi). A total of 81 sampling areas were investigated, 54 in
oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling
area was expressed with a synthetic index namely phytosanitary class (PC). Oak stands showed severe
symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands
were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline.
On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea,
Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees
Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore,
twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks.
... However, it can act as an opportunistic pathogen when the host is weakened by abiotic or biotic factors such as prolonged drought periods Motta 1995, Vannini andScarascia Mugnozza 1991) or when attacked by other pathogens. Thus, these fungi are facultative saprophytes that spend most of their life cycle as parasites but can also persist for long periods on dead material (Nugent et al. 2005). B. mediterranea can rapidly colonize xylem and bark tissues to induce necrosis and canker formation, and to accelerate tree decline and eventually cause death (Desprez-Loustau et al. 2006;Linaldeddu et al. 2011). ...
The genus Biscogniauxia is paraphyletic to members of the family Xylariaceae and includes at least 52 species to date that are mainly pathogens of dicotyledonous angiosperm trees. Most of these are forest trees, such as those in the genera Acacia, Acer, Alnus, Eucalyptus, Fraxinus, Populus, and Quercus, and other species of minor importance. Biscogniauxia spp. have been reported as endophytes or secondary invaders that attack only stressed plants. During a survey in rosaceous orchards in southern Italy, several charcoal cankers were observed and stroma samples were collected. A collection of 31 Biscogniauxia isolates was analyzed. Their phylogenetic relationships were determined through study of the internal transcribed spacer, p-tubulin, and actin gene sequence's. Combining morphological, cultural, and molecular data, a new species of Biscogniauxia is described here as Biscogniauxia rosacearum. This new species was isolated for the first time from rosaceous hosts in Apulia. Pathogenicity tests showed that it causes symptoms on stems when artificially inoculated and produces stromata on the bark surface.
... An example is the Blatent phase^of these microorganisms defined by Verhoeff (1974) as a Bquiescent or dormant parasitic relationship, which, after a time, can change into an active one^. The presence of these latent invaders in healthy woody plants has been observed for different fungal species, such as those included in the Xylariaceae and Botryosphaeriaceae families (Hendry et al. 2002;Nugent et al. 2005;Slippers and Wingfield 2007). ...
Latent invaders represent the first step of disease before symptoms occur in the host. Based on recent findings, tumors are considered to be ecosystems in which cancer cells act as invasive species that interact with the native host cell species. Analogously, in plants latent fungal pathogens coevolve within symptomless host tissues. For these reasons, similar detection approaches can be used for an early diagnosis of the invasion process in both plants and humans to prevent or reduce the spread of the disease. Molecular tools based on the evaluation of nucleic acids have been developed for the specific, rapid, and early detection of human diseases. During the last decades, these techniques to assess and quantify the proliferation of latent invaders in host cells have been transferred from the medical field to different areas of scientific research, such as plant pathology. An improvement in molecular biology protocols (especially referring to qPCR assays) specifically designed and optimized for detection in host plants is therefore advisable. This work is a cross-disciplinary review discussing the use of a methodological approach that is employed within both medical and plant sciences. It provides an overview of the principal qPCR tools for the detection of latent invaders, focusing on comparisons between clinical cancer research and plant pathology, and recent advances in the early detection of latent invaders to improve prevention and control strategies.
... The charcoal canker disease is derived by the contamination of a fungus denominated Nummularia regia (syn. Biscogniauxia mediterranea) and affects cork oak trees (Nugent et al., 2005). This fungus destroys the cork tree tissues (phloem and xylem), so the tree becomes dark (carbon colour) and hollow. ...
Carnivores have a key role in ecosystems and their populations are declining at an increasing rate. Habitat loss and degradation through agricultural practices are among the most serious menaces affecting carnivore survival. Agricultural landscapes are dominant in Western Europe and in several places worldwide are changing quickly into more intensive practices. Therefore, it is important to understand how small carnivore occurrence and abundance is affected by these changes in order to find ways to manage agricultural and grazing systems in a sustainable way, allowing both biodiversity and production to co-exist. We present three case studies in Natura 2000 areas, mainly covered by private agricultural land (livestock, cereal crops, oak, pine and eucalyptus plantations) in southern Portugal. In areas of dominant traditional agro-silvo-pastoral systems (montado) small and middle-sized carnivores tend to occur in a mosaic of montado and shrubs. We found that the occurrence of one of the forest species was positively related with the density of trees and shrubs, soil organic matter content, and Shannon's index of vegetation vertical diversity. The presence of livestock and extension of game-estate areas also seem to influence carnivore occurrence. In areas of extensive cereal crops, the presence of shrubs and age of forest plantations play an important positive role for the carnivore community. Mainly our results suggest that maintaining a sustainable mosaic embracing montado, shrubland and open land areas, may allow higher species richness and abundance by enhancing connectivity between crucial areas. The implementation of this kind of agricultural practices considering the landowners needs is the key issue to achieve the main carnivore conservation goals in Southern Portugal.
... This fungus spends part of its life cycle as endophyte and may induce disease symptoms on its host under unfavorable environmental conditions. In prolonged summer drought, B. nummularia takes advantage of the altered host physiology, invades host tissue and causes elongated blackish bark lesions on trunk and branches, known as strip-cankers, and wood decay in mature trees (Hendry et al. 1998, Nugent et al. 2005). In the related species B. mediterranea (Vannini et al. 2009), outbreak of disease on oaks is likely to follow an increase in endophytic colonization. ...
Biscogniauxia nummularia is a xylariaceous fungus known as a common endophyte of European beech, living in plant tissues without development of symptoms, or even inducing strip-cankers and wood decay on trees stressed by drought. We studied the presence of the fungus in apparently healthy beech trees, growing in two different bioclimatic zones characterized by Continental and Mediterranean climates. Asymptomatic twigs were collected in each zone over the season and evaluated for the presence of B. nummularia infections using both cultural and qPCR methods. Results from qPCR indicated differences in the detection of B. nummularia among the seasons and between the study sites. In both sites the highest frequency of detection was in summer. B. nummularia was more frequently detected in the Mediterranean bioclimatic area, where drought is more common. These results suggest that B. nummularia may be a possible bioindicator of beech health stands.
Olive is a perennial tree able to grow and survive in Mediterranean conditions due to its climate adaptations. In this study, we observed a new disease characterised by leaf tip blight, shoot blight, and dieback in olive trees in the Southeast Anatolian region of Türkiye. Six fungal isolates were obtained from the symptomatic trees. Classical methods based on macroscopic and microscopic observations revealed that the isolates were similar to Sordaria macrospora . Total DNA was isolated and PCR‐amplified with primer pairs for the ITS , LSU , β‐tubulin, and Tef‐1α gene regions, and the resulting sequences were BLASTed in the NCBI database. The similarity was 99%–100% to isolates of S. macrospora . The similarity of the pathogen to other Sordaria spp. isolates was determined by constructing a phylogenetic tree using MEGA X software and the neighbour‐joining method. Out of six isolates, one representative isolate was selected for subsequent studies. In pathogenicity tests on 2‐year‐old olive seedlings, blight was observed starting from the tips of leaves and shoots to the base, and the pathogen was successfully reisolated, fulfilling Koch's postulates. This is the first report of S. macrospora acting as a pathogen in olive trees.
It is well-known that over-harvesting of timber threatens saproxylic fungal diversity. However, quantifying species loss is difficult due to the lack of spatial explicit baseline studies and related continuous temporal investigations. The first step to achieve basic information are systematic inventories in a given area. The Hyrcanian forest is among the most important forest biodiversity hotspots in Iran, which has been added to the UNESCO World Heritage List in 2019. Therefore, we collected 193 samples of wood-inhabiting fungi based on systematic surveys considering all seasons in Hyrcanian old-growth forests during five years (2016-2021). Species collected belonged to the fungal phylum Basidiomycota (169 species, 99 genera, 48 family and 1 incertae sedis family, 11 orders and 3 classes) and Ascomycota (24 species, 17 genera, 12 family, 6 orders and 4 classes). One collected species fall within the kingdom Protozoa, Lycogala epidendrum . 58 species and 16 genera were new for the Iranian funga; 11 and seven species were new for Gilan and Mazandaran province respectively; 20 species and one genus were new for Golestan province and one genus was a new record for the Hyrcanian forests funga. Our inventory highlights the need for documenting saproxylic fungi and to quantify the diversity in hotspot regions. This inventory might serve as a baseline for further studies to track diversity change due to forest management and climate change and to provide concepts to prevent fungal diversity from future loss.
The chemical diversity from Biscogniauxia capnodes SWUF15-40 fungus, cultivated in yeast-malt extract medium was studied. The choice of medium was inspired by the OSMACs strategy, which had previously been cultivated in PDB medium. This resulted in an array of bioactive compounds being discovered. The IR, NMR, MS, and XRD data, together with the calculated 13C NMR chemical shifts and ECD spectra data were thoroughly analysed, which led to the determination of two new isopimarane (1 and 2), and three guaiane (3-5) derivatives, together with four known compounds (6-9). Cyclic pentapeptide (9) showed inhibitory activity against cancer cells (HeLa, HT-29, PC-3, and A549) proliferation and nitric oxide (NO) production in LPS-stimulated RAW264.7 cells with IC50 values in the ranges of 11.38 - 17.87 µM, and 58.88 µg/mL, respectively. The results demonstrated that manipulating growth conditions can increase the possibility of discovering many more bioactive compounds in fungi.
Background
As forested natural habitats disappear in the world, traditional, shade-coffee plantations offer an opportunity to conserve biodiversity and ecosystem services. Traditional coffee plantations maintain a diversity of tree species that provide shade for coffee bushes and, at the same time, are important repositories for plants and animals that inhabited the original cloud forest. However, there is still little information about shade-coffee plantation’s fungal diversity despite their relevance for ecosystem functioning as decomposers, symbionts and pathogens. Specifically, it is unknown if and what mycorrhizae-forming fungi can be found on the branches and trunks of coffee bushes and trees, which hold a diversity of epiphytes. Here, we evaluate fungal communities on specific plant microsites on both coffee bushes and shade trees. We investigate the ecological roles played by this diversity, with a special focus on mycorrhizae-forming fungi that may enable the establishment and development of epiphytic plants.
Methods
We collected 48 bark samples from coffee bushes and shade trees (coffee; tree), from four plant microsites (upper and lower trunks, branches and twigs), in two shade-coffee plantations in the Soconusco region in southern Mexico, at different altitudes. We obtained ITS amplicon sequences that served to estimate alpha and beta diversity, to assign taxonomy and to infer the potential ecological role played by the detected taxa.
Results
The bark of shade trees and coffee bushes supported high fungal diversity (3,783 amplicon sequence variants). There were no strong associations between community species richness and collection site, plant type or microsite. However, we detected differences in beta diversity between collection sites. All trophic modes defined by FUNGuild database were represented in both plant types. However, when looking into guilds that involve mycorrhizae formation, the CLAM test suggests that coffee bushes are more likely to host taxa that may function as mycorrhizae.
Discussion
We detected high fungal diversity in shade-coffee plantations in Soconusco, Chiapas, possibly remnants of the original cloud forest ecosystem. Several mycorrhiza forming fungi guilds occur on the bark of coffee bushes and shade trees in this agroecosystem, with the potential of supporting epiphyte establishment and development. Thus, traditional coffee cultivation could be part of an integrated strategy for restoration and conservation of epiphytic populations. This is particularly relevant for conservation of threatened species of Orchidaceae that are highly dependent on mycorrhizae formation.
Cork oak is a tree species with ecological importance that contributes to economic and social development in the Mediterranean region. Cork oak decline is a major concern for forest sustainability and has negative impacts on cork oak growth and production. This event has been increasingly reported in the last decades and seems to be related with climate changes. Biscogniauxia mediterranea is an endophytic fungus of healthy cork oak trees that turns into a pathogen in trees weaken by environmental stress. Understanding the drivers of B. mediterranea populations diversity and differentiation is expected to allow a better control of cork oak decline and preserve forest sustainability. Endophyte isolates from different cork oak forests were identified as B. mediterranea and their genetic diversity was evaluated using phylogenetic and microsatellite-primed PCR analyses. Genetic diversity and variability of this fungus was correlated with environmental/phytosanitary conditions present in forests/trees from which isolates were collected. High genetic diversity and variability was found in B. mediterranea populations obtained from different forests, suggesting some degree of isolation by distance. Bioclimate was the most significant effect that explained the genetic variability of B. mediterranea , rather than precipitation or temperature intensities alone or disease symptoms. These findings bring new implications for the changing climate to cork oak forests sustainability, cork production and quality.
The oak charcoal disease is an agent oak decline in forests of Iran, but there is no accurate
information about risks and its threats. Therefore, in order to evaluate the relationship
between severity of disease and host characteristics (diameter at breast height, crown position
and trunk length), 385 oaks (Quercus castaneifolia) were considered by using point centered
quarter method in Qoruq Forest Park. These oak trees were grouped in five levels based on
the health status (healthy, low, moderate, severe and declines). For data analysis, Poisson
regression, one-way ANOVA and Kruskal-Wallis and Duncan's test were applied by using R
statistical software. The results showed that severity of disease had a significant relationship
with diameter at breast height and crown position but the effect of trunk length was not
significant. The Poisson regression analysis results showed that by increasing exp=(0.7)=
2.013 cm in diameter, it is expected the damage grade level rises one degree. Furthermore, the
highest percentage of disease incidence and severity had occurred in the trees with a diameter
greater than 35 cm and with middle crown position. In general, it can be concluded that the
individual characteristics of trees can be influential factors in the severity and epidemic of the
charcoal disease in oak trees. The development of epidemic models needs to better
understanding of how the properties of the host influence the severity and spread of charcoal
disease in long-term course of the disease.
Abstract
Background and objectives: Biscogniauxia mediterranea as an opportunistic
fungus and cause of Charcoal disease is a major problem in the oak forest stands
with Mediterranean and sub-Mediterranean climate. For the first time in Iran
charcoal disease was observed in 2011 in Hyrcanian and Zagros forests on the
species of Quercus castaneifolia, Zelkova carpinifolia, and Q. brantii, respectively.
However there is not accurate information about the risks and threats of this
disease in the country's forests.
Materials and methods: This research focuses on evidences and effective pattern
on presence, spread and comprehension of processes and interaction of charcoal
disease agent with forest trees and finally its control and management methods.
Results: Symptoms of B. mediterranea cankers include the reduced canopy crown
volume, dry branches and pieces of the bark around tree. Many factors, such as
defoliation, saturated soil moisture, soil compaction and removal, excavation
within the root crown, drought, ground water table drop, nutrients limitation,
competition or high density of trees and dust can cause ecosystem weakness and
spread of the disease. There is not an efficient method to control the disease except
to cut and remove the infected trees from forest. But the most effective
management strategy is to avoid stress on trees, so that trees can improve their
ability to defend themselves against the disease. Few in vitro studies have been
performed via antagonistic fungi for biological control of disease, but no effective
method in forest ecosystem has been reported.
Conclusion: Most likely the forests are affected by stress due to climatic change;
therefore, the effects of climate changes on healthy forests should be carefully
evaluated. The climate changes cause pathogens outbreak and migration and
introduction of new hosts and potential vectors. These factors increase outbreak
and spatial distribution of forest trees diseases. Therefore because of the severe
damage of this disease to forests in north and west of Iran, more comprehensive
studies should be done in these forests to provide useful approaches to control oak
charcoal disease.
Spatial pattern and disease severity of charcoal canker
in Hyrcanian forests, north of Iran
J. Karami1, M.R. Kavosi1, M. Babanezhad2
1Department of Forest Sciences, Gorgan University of Agricultural Sciences
and Natural Resourses, Golestan, Iran
2Department of Statistics, Faculty of Sciences, Golestan University, Golestan, Iran
ABSTRACT: This research investigated the population density of infected trees with charcoal canker disease and the
interaction across the severity of the disease on Quercus castaneifolia in Hyrcanian forests, north of Iran. We used twodimensional spatial analysis tools with data gathered in point-centred quarter format in 2013. We investigated the cooccurrence of the severity of the disease symptoms using the paired quadrat covariance analysis. The results showed that
nearly 54% of the oak trees were affected by the disease so that the dead trees and high disease severity were strongly clustered at broader scales (800 m), the trees with only limited exudates and signs of the activity of Biscogniauxia mediterranea
(De Not.) Kuntze occurred in the clusters away from the dead trees. The crown mortality and beetle-infested trees cooccurred with mortality and were strongly correlated. Also, the findings of this research showed that the density of trees
per hectare was one of the influential factors on the damage severity of the charcoal canker disease, so that reducing the
density could increase the damage severity of the disease.
Keywords: Biscogniauxia mediterranea; oak decline; point-centred quarter method; Quercus castaneifolia
Biscogniauxia mediterranea is a xylariaceous ascomycete responsible for ‘charcoal disease’, the most frequent disease of cork oak in the Mediterranean basin. However, little is known regarding this fungus in North Africa. This is the first report on the morphological and genetic diversity of B. mediterranea populations in Tunisia.
A total of forty-eight isolates from cork oak trees, corresponding to three different sites and three tree parts, were identified as B. mediterranea based on morphological and molecular diagnosis. Variability among the isolates was evaluated using morphological traits and microsatellite-primed PCR (MSP-PCR). B. mediterranea isolates showed high variability in culture, specifically in colony color. A high level of genetic diversity within populations and within tree parts was detected (H = 0.417, I = 0.605, and H = 0.415, I = 0.601 respectively). Significant genetic differentiation among populations (GST = 0.116 and ΦST = 0.137; p < 0.001) was determined. However, a low genetic differentiation among tree parts (GST = 0.066 and ΦST = 0.018; p = 0.07) was observed. Principal coordinate analysis showed that genetic divergence was partially related to the geographical origin. Cluster analysis based on morphological traits showed that the grouping of the isolates occurs independently of the geographic location and the tree part. The effective number of alleles (Ne), the Nei's gene diversity index (H), the Shannon's information index (I), the colony color and the presence of exudates were significantly correlated with the altitude and the rainfall. The number of alleles (Na), the percentage of polymorphic loci (PPL), the texture and the density of the mycelium were significantly correlated with the temperature. These results provide a deeper understanding of population genetics of B. mediterranea and its adaptation to environmental conditions which could help to develop control strategies against charcoal canker disease.
From 2012 to 2015, several field surveys were conducted throughout forest areas in the north of Iran in order to determine the occurrence of species of Botryosphaeriaceae on forest trees. Fungal isolations were made from symptomatic branches of 20 tree genera including Acer, and Zelkova, as well as fruiting bodies formed on the surface of woody debris. Morphological identification along with molecular analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the nuclear ribosomal DNA (rDNA) and a partial sequence of translation elongation factor 1-α (tef-1α) gene showed that at least nine species of Botryosphaeriaceae occur on forest trees in the north of Iran. These include Dothiorella sarmentorum, Dothiorella plurivora, Neofusicoccum parvum, Botryosphaeria dothidea, Neoscytalidium novaehollandiae, Diplodia seriata, Diplodia sapinea, Lasiodiplodia mahajangana and Diplodia intermedia. Pathogenicity tests were conducted for selected isolates from each species on six tree species (Mespilus germanica, Punica granatum, Parrotia persica, Alnus glutinosa, Quercus castaneifolia and Pterocarya fraxinifolia) under field conditions. Results of the pathogenicity tests showed a variation in lesion lengths (virulence) and re-isolation frequencies of inoculated species on branches of trees, Neoscytalidium novaehollandiae, B. dothidea and D. intermedia being the most virulence species. Based on host plant species, the majority of Botryosphaeriaceae species are new 5/11/2019 Diversity and pathogenicity of Botryosphaeriaceae species on forest trees in the north of Iran | SpringerLink https://
Oak decline is an expression describing death and drying up of oak trees. The present research evaluated the relationship between various geographical directions and altitude and some factors predisposing Persian oak (Quercus brantii Lindl.) decline, such as charcoal disease and oak wood boring insects in a 100 hectares area of the Shurabad forests in Lorestan Province of Iran. A 200 by 200 m sampling network was first designed on a regular-random (systematic) basis, and the trees were sampled from 1500-m² circular plots. Information including hillside direction, altitude, infection site (on tree crown or on trunk), type of infection (charcoal disease or wood borers), crown vigor, and heights of the infection sites on the trees was recorded in each sample plot. Results indicated the significant relationships of infection type and severity with altitude, geographical direction, slope, and location of the sample plot at the significance level of 5%. Wood borers were the most common cause of infection. There was very little attack by charcoal disease in the study area. Most diseased trees were in the valley, in a northerly direction, at the 1101–1150 m elevation class and the 41–50% slope class. There were very few healthy trees in the study area, and most of them were on the ridges, in a southwesterly direction, at the 1151–1200 m altitude class and the 11–20% slope class.
Widespread but locally severe disease of Nothofagus cunninghamii occurs in Tasmanian rainforests.
Signs and symptoms of disease in individual trees include attack by the mountain pinhole borer Platypus
subgranosus, chlorosis-necrosis and abscission of foliage and sudden wilting of shoots and foliage of
affected trees, discoloration of sapwood from the roots to the upper stem and the formation of dark
grey-black fungal felts on the bark or cross-cut surfaces of infected stems. Naturally infected trees may
take from less than 1 year to more than 2.5 years to die from the time of initial infection.
The hyphomycete Chalara australis J. Walker & G. A. Kile, sp. nov. is isolated consistently from the
discoloured wood in dying trees. The species is described and its taxonomic affinities with C. quercina,
C. ungeri, C. neocaledoniae, C. nothofagi and the Chalara anamorphs of Ceratocystis virescens discussed.
No teleomorph has been found.
Artificial inoculation of C. australis into healthy seedlings, saplings and large trees of
N. cunninghamii reproduced the disease and confirmed that the species is an aggressive primary pathogen.
None of the other fungi isolated directly from P. subgranosus, its tunnels or adjacent discoloured
wood or the upper stems and branches of dying N. cunninghamii were pathogenic in seedlings. It is
uncertain whether C. australis is vectored by P. subgranosus or if fungal infection precedes
P. subgranosus infestation.
The general significance of Chalara spp. in relation to the Fagaceae is discussed.
Ascomycete fungi from the Xylariaceae and Diatrypaceae responded in three distinct ways when grown in dual culture with callus material of beech (Fagus sylvatica L.). Growth of the putative weak pathogens Biscogniauxia nummularia (Bull.) O. Kuntze and Eutypa spinosa (Pers.) Tul. & C. Tul. was stimulated whilst the saprotrophs Ustulina deusta (Hoffm.) Lind. and Xylaria polymorpha (Pers.) Grev. were unaffected by the presence of callus. Sapwood-colonizing fungi displayed a range of responses, with Diatrype stigma (Hoffm.) Fr. being unaffected, Diatrype disciformis (Hoffm.) Fr. stimulated, and Hypoxylon fragiforme (Pers.: Fr.) Kickx and ‘Hypoxylon purpureum’ inhibited by the presence of callus. Changes in morphology were evident in many of the fungi during interactions, with yeast-like forms being produced by those members of the Xylariaceae which have been recognized as endophytes. Reciprocally, high concentrations of cell free extracts of some of the Xylariaceous fungi resulted in necrosis or inhibition of callus growth, while at sub-lethal concentrations marked stimulation of growth was evident. The importance of these results with respect to pathogenicity testing and elucidation of the biology of tree–fungus interactions is discussed.
One species of Basidiomycete and two species of Pyrenomycetes are reported from the British Isles for the first time, on the basis of collections from the Esher Commons SSSI complex, Surrey. A new genus, Pseudovalsaria, is proposed to accommodate Phaeosperma foedans Karsten, and P. niesslii Winter and Valsaria lignicola Teng & Ou are reduced to synonymy under this species. A collection on Pinus from Esher Common represents a new host genus for P. foedans.
A new species of Biscogniauxia with a single appendage on the ascospore is described. Species with similar ascospores which were formerly placed in Hypoxylon sect. Applanata are combined in Biscogniauxia.
Mycophagy of Biscogniauxia stromata by rats and beetles on
New Zealand's offshore islands is illustrated and discussed.
Hypoxylon mediterraneum (De Not.) Mill. proved to be a weakness parasite on Quercus cerris. Evidences are given about the association between pathogenicity of the fungus and water stress of the host.
The pathology and distribution of European beech trees bearing elongated bark lesions (strip-cankers) were investigated. Two types of canker were recognized: those on small trees (<40 cm diameter at breast height (dbh): 1·4 m above ground level) which bore fruit bodies of the xylariaceous ascomycete Biscogniauxia nummularia (Bull.) O. Kuntze, and those on larger specimens (>40 cm dbh) which were consistently associated with the diatrypaceous ascomycete Eutypa spinosa (Pers.) Tul. & C. Tul. All cankers were strictly annual, having formed during single growing seasons following periods of low water availability. The regional and local distribution of trees bearing lesions also appeared to be correlated with environmental conditions, being most severe where low rainfall or high temperatures had occurred. Population studies of the associated fungi, generally considered as saprotrophs, indicated the presence of unique genotypes within individual cankered trees and provided no evidence for the existence of pathotypes within either species. Within the decay columns which underlay canker surfaces, both B. nummularia and E. spinosa formed longitudinally extensive genets, implying non-mycelial spread in colonization. Suppression of both inter- and intraspecific incompatibility between fungi occurred in regions of canker decay columns with elevated water contents. The possible significance of coexistence between the ascomycetes B. nummularia and ‘Hypoxylon purpureum’ (sensu Sharland & Rayner, 1989b) and of the formation of heterokaryons by E. spinosa is discussed.
This paper outlines current positions on systematic arrangements of the Xylariaceae, discusses the value of the different characters used in attaining these arrangements, and reviews the activities of members of the family in nature. The taxonomic significance and potential ecological role of the many secondary metabolites produced by xylariaceous taxa is evaluated. The importance of the Xylariaceae in wood decomposition and as agents of disease is discussed. Aspects of their distribution in relation to host, habitat and climate are presented.
Summary • Effects of temperature and gaseous regimes on development of fungal communities, from latent infections in twigs, branches and stems of European beech (Fagus sylvatica), were investigated through controlled drying. • Hypoxylon fragiforme was identified as a latent invader within the xylem of all orders of host stem and branch material. Explanations for the incongruence of this finding with results from previous experiments are considered. • Incubation under an atmosphere of 100% CO2 prevented the growth of the endophytic fungi present, despite drying of the wood. Fungal growth at low temperatures and at low oxygen tensions was less than could be explained through direct effects, and there was evidence for an indirect effect involving active host defence. Elevated temperatures favoured establishment of the early-colonizing ascomycete Biscogniauxia nummularia and the late-colonizing basidiomycete Coniophora puteana, while low oxygen tensions favoured colonization by Trichoderma sp. • The ecological significance of these observations is discussed.
O carvão do enttrecasco Hypoxylon mediterraneum (Ces. et De Not.) Publicaco˘ es direccão Geral dos Serviços florestais e
- M A Barbosa
- F De
Barbosa, M.A. de F. (1958). O carvão do enttrecasco Hypoxylon mediterraneum (Ces. et De Not.) Publicaco˘ es direccão Geral dos Serviços florestais e Agricolas 25: 95-132.
Decline of beech associated with Biscogniauxia mediterranea in Italy
- G Granata
- A J S Whalley
Granata, G. & Whalley, A.J.S. (1994). Decline of beech associated with Biscogniauxia mediterranea in Italy. Petria 4: 111-116.
The genus Biscogniauxia
- Y.-M, Rogers Ju
- J D San
- F Granmo
Ju, Y.-M, Rogers, J.D., San Martin Gonzales, F. & Granmo, A. (1998). The genus Biscogniauxia. Mycotaxon 66: 1-98.
Principais do sobreiro
- A M Macara
Macara, A.M. (1974). Principais do sobreiro. Boletim do Instituto dos Produtos Florestats, Cortica 430: 149-156.
Estimativa em 1975. Dos prejuizos
- A M Macara
Macara, A.M. (1975). Estimativa em 1975. Dos prejuizos