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Geographic distribution and sampling locations of adult trees and progeny of Dimorphandra wilsonii. Yellow , Cerrado; white , seasonal forests; star , Belo Horizonte, the capital city of the State of Minas Gerais; contours of neighbouring cities are given in gray for reference purposes. Please refer to Table 1 for codes
Source publication
Naturally rare species have a higher probability of stochastic extinction due to genetic, demographic, or environmental hazards; human disturbance may intensify these threats. Rare species may therefore be in need of short-term intervention to survive. The ecosystem with the second highest biodiversity in Brazil, the Cerrado, is suffering from frag...
Contexts in source publication
Context 1
... Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) provided us with data on the location of the trees (Fig. 1, Table 1). A total of 20 adult trees, 20-40 fruit from 13 trees, and 10 regenerants of D. wilsonii were sampled (Table 1). Amongst the regenerants, one had a natural origin; the other nine had been planted by the Belo Horizonte Zoo-Botanic Foundation as part of a conservation program ( Fernandes et al. 2007). For mating system studies, fruit ...
Context 2
... congruent with the geographic location. The Northern group (depicted in green in Fig. 2) contained the seven progeny from PARa, along with PARb and CAE. The Southern group (depicted in red in Fig. 2) consisted of LAS and MAT, and included PEQ and PIN; the latter two progeny came from mother trees located at sites with an intermediate location (Fig. 1). There was some admixture between the two groups. In the Northern group, some seedlings contained a genetic component from the Southern group, especially those from PARa2, PARa4 and PARb. The genetic profile of the mother tree of PARb was mostly of Southern origin, which explained the admixture in some of the PARb seedlings. However, ...
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... and D. gardneriana Tul., are commonly found in the Cerrado and are commercially valuable due to their active chemical compounds (Silva 1986). The geographically narrow endemic species, D. wilsonii Rizzini is considered to be seriously threatened with extinction; the species is found at a few neighboring sites of a Cerrado/ Atlantic Forest ecotone in the central parts of Minas Gerais state (Fernandes and Rego 2014;Vinson et al. 2015). A previous study suggested that D. wilsonii may be an interspecific hybrid between D. mollis from the Cerrado and D. exaltata Schott from the Atlantic Forest (Muniz et al. 2020). ...
The tree genus Dimorphandra (Fabaceae), which contains 26 species divided into three subgenera, was studied using DNA sequence data from six chloroplast genome regions (cpDNA) and the nuclear internal transcribed spacer (ITS). The analyses, which included Bayesian phylogenies and haplotype networks, ancestral area reconstructions, and ecological niche modeling, allowed for exploring the evolutionary history of Dimorphandra. Within the subgenus Phaneropsia, the cpDNA sequence data were more closely-related to species from the genus Mora, while the ITS sequence data displayed a closer phylogenetic relationship with the subgenus Pocillum. This incongruence may be due to incomplete lineage sorting associated with ancient polymorphisms. The Amazonian Dimophandra lineages were highly polymorphic and divergent, while those from the Cerrado and the Atlantic Forest had low levels of polymorphisms. The Amazon likely gave rise to the Dimophandra lineage that produced the Cerrado species, while a Cerrado lineage likely gave rise to the Atlantic Forest species. Habitat shifts were identified as a key factor in shaping the late evolutionary history of Dimorphandra.
... After the extensive search performed in the frame of the conservation program for D. wilsonii, about 420 individuals are currently known Downloaded from https://academic.oup.com/aob/advance-article-abstract/doi/10.1093/aob/mcaa066/5818978 by guest on 13 April 2020 A c c e p t e d M a n u s c r i p t and there are most likely very few unknown individuals in nature (Fernando Moreira Fernandes, personal communication). Until now, only two genetic studies have been performed to investigate the genetic diversity of D. wilsonii (Souza and Lovato 2010;Vinson et al. 2015), based on the sampling of only 20-22 adult trees known until then. The study of Vinson et al. (2015) analysed D. wilsonii progenies and found that they carried alleles unobserved in known adults, leading to a suspicion of hybridization with the co-occurring D. mollis Benth. ...
... Until now, only two genetic studies have been performed to investigate the genetic diversity of D. wilsonii (Souza and Lovato 2010;Vinson et al. 2015), based on the sampling of only 20-22 adult trees known until then. The study of Vinson et al. (2015) analysed D. wilsonii progenies and found that they carried alleles unobserved in known adults, leading to a suspicion of hybridization with the co-occurring D. mollis Benth. Furthermore, Rego (2014) showed that D. wilsonii produced fruits with viable seeds differences in the quality of fruits and seeds of from both manually selfed and crosspollinated flowers. ...
... During fieldwork, we observed some putative D. wilsonii individuals with intermediate phenotypic characteristics between D. wilsonii and D. mollis or between D. wilsonii and D. exaltata suggesting that hybridization may be occurring between D. wilsonii and the other two species. Additionally, an unexpected pattern of heterozygosity excess at the individual level was previously observed in small samples of D. wilsonii genotyped with two different sets of SSR loci (Souza 2012;Vinson et al. 2015). This pattern could represent a consequence of ongoing hybridization, as suggested in recent studies that observed high individual heterozygosity and negative inbreeding coefficients (representing a heterozygosity excess) in populations dominated by hybrids of recent origin, i.e., F1s and few F2s or recombinant hybrids (Zalapa et al. 2010;Marques et al. 2016;Zeng et al. 2016). ...
Abstract
Backgrounds and Aims
Dimorphandra wilsonii Rizzini, a critically endangered and protected tree, has a restricted distribution in the ecotone between the Cerrado and the Atlantic Forest in southeastern Brazil. In this area, it co-occurs with D. mollis Benth., a common tree from the Cerrado, and D. exaltata Schott., a rare tree from the Atlantic Forest. Previous studies of D. wilsonii indicated heterozygosity excess at the individual level. Field observation of some intermediate phenotypes between D. wilsonii and both congeners suggests hybridization of D. wilsonii with D. mollis and/or D. exaltata. Here, we tested the hypothesis that D. wilsonii may be originated from hybridization between D. exaltata and D. mollis. We also performed cytogenetic analysis to examine if the heterozygote excess could be explained by polyploidy in D. wilsonii.
Methods
We evaluated the genetic diversity and population structure of D. wilsonii using eleven nuclear SSRs genotyped in 152 individuals sampled across the taxon’s range. We performed comparative genetic analyses using overlapping SSR markers between D. wilsonii and previously published SSR data in D. mollis and D. exaltata to perform a series of allelic comparisons, multivariate and Bayesian analysis.
Key results
Our results suggest that D. wilsonii individuals most likely correspond to F1 hybrids between D. exaltata and D. mollis. Cytogenetic analysis indicated that D. wilsonii is diploid with the same chromosome number as D. mollis (2n = 2x = 28).
Conclusions
Our study raises questions about the taxonomic status and the evolutionary future of D. wilsonii. We suggest that the conservation and management strategy for D. wilsonii should be revised and that it should take into account both parental Dimorphandra species in the ecotone, with special emphasis on the threatened D. exaltata. Finally, this study highlights the value of genetic information for the design of conservation strategies.
... After the extensive search performed in the frame of the conservation program for D. wilsonii, about 420 individuals are currently known Downloaded from https://academic.oup.com/aob/advance-article-abstract/doi/10.1093/aob/mcaa066/5818978 by guest on 13 April 2020 A c c e p t e d M a n u s c r i p t and there are most likely very few unknown individuals in nature (Fernando Moreira Fernandes, personal communication). Until now, only two genetic studies have been performed to investigate the genetic diversity of D. wilsonii (Souza and Lovato 2010;Vinson et al. 2015), based on the sampling of only 20-22 adult trees known until then. The study of Vinson et al. (2015) analysed D. wilsonii progenies and found that they carried alleles unobserved in known adults, leading to a suspicion of hybridization with the co-occurring D. mollis Benth. ...
... Until now, only two genetic studies have been performed to investigate the genetic diversity of D. wilsonii (Souza and Lovato 2010;Vinson et al. 2015), based on the sampling of only 20-22 adult trees known until then. The study of Vinson et al. (2015) analysed D. wilsonii progenies and found that they carried alleles unobserved in known adults, leading to a suspicion of hybridization with the co-occurring D. mollis Benth. Furthermore, Rego (2014) showed that D. wilsonii produced fruits with viable seeds differences in the quality of fruits and seeds of from both manually selfed and crosspollinated flowers. ...
... During fieldwork, we observed some putative D. wilsonii individuals with intermediate phenotypic characteristics between D. wilsonii and D. mollis or between D. wilsonii and D. exaltata suggesting that hybridization may be occurring between D. wilsonii and the other two species. Additionally, an unexpected pattern of heterozygosity excess at the individual level was previously observed in small samples of D. wilsonii genotyped with two different sets of SSR loci (Souza 2012;Vinson et al. 2015). This pattern could represent a consequence of ongoing hybridization, as suggested in recent studies that observed high individual heterozygosity and negative inbreeding coefficients (representing a heterozygosity excess) in populations dominated by hybrids of recent origin, i.e., F1s and few F2s or recombinant hybrids (Zalapa et al. 2010;Marques et al. 2016;Zeng et al. 2016). ...
Backgrounds and aims:
Dimorphandra wilsonii Rizzini, a critically endangered and protected tree, has a restricted distribution in the ecotone between the Cerrado and the Atlantic Forest in southeastern Brazil. In this area, it co-occurs with D. mollis Benth., a common tree from the Cerrado, and D. exaltata Schott., a rare tree from the Atlantic Forest. Previous studies of D. wilsonii indicated heterozygosity excess at the individual level. Field observation of some intermediate phenotypes between D. wilsonii and both congeners suggests hybridization of D. wilsonii with D. mollis and/or D. exaltata. Here, we tested the hypothesis that D. wilsonii may be originated from hybridization between D. exaltata and D. mollis. We also performed cytogenetic analysis to examine if the heterozygote excess could be explained by polyploidy in D. wilsonii.
Methods:
We evaluated the genetic diversity and population structure of D. wilsonii using eleven nuclear SSRs genotyped in 152 individuals sampled across the taxon's range. We performed comparative genetic analyses using overlapping SSR markers between D. wilsonii and previously published SSR data in D. mollis and D. exaltata to perform a series of allelic comparisons, multivariate and Bayesian analysis.
Key results:
Our results suggest that D. wilsonii individuals most likely correspond to F1 hybrids between D. exaltata and D. mollis. Cytogenetic analysis indicated that D. wilsonii is diploid with the same chromosome number as D. mollis (2n = 2x = 28).
Conclusions:
Our study raises questions about the taxonomic status and the evolutionary future of D. wilsonii. We suggest that the conservation and management strategy for D. wilsonii should be revised and that it should take into account both parental Dimorphandra species in the ecotone, with special emphasis on the threatened D. exaltata. Finally, this study highlights the value of genetic information for the design of conservation strategies.
... Our populations showed significant inbreeding coefficients, indicating a departure from random mating within populations. Although the mating system of D. exaltata is not known, it is probably similar to that of the congeneric D. wilsonii, which has self-compatibility 26 but mainly performs outcrossing 48 . The inbreeding found in D. exaltata may be due to selfing or mating between related individuals (biparental inbreeding). ...
Although there is a consensus among conservation biologists about the importance of genetic information, the assessment of extinction risk and conservation decision-making generally do not explicitly consider this type of data. Genetic data can be even more important in species where little other information is available. In this study, we investigated a poorly known legume tree, Dimorphandra exaltata, from the Brazilian Atlantic Forest, a hotspot for conservation. We coupled species distribution models and geospatial assessment based on herbarium records with population genetic analyses to evaluate its genetic status and extinction risk, and to suggest conservation measures. Dimorphandra exaltata shows low genetic diversity, inbreeding, and genetic evidence of decrease in population size, indicating that the species is genetically depleted. Geospatial assessment classified the species as Endangered. Species distribution models projected a decrease in range size in the near future (2050). The genetic status of the species suggests low adaptive potential, which compromises its chances of survival in the face of ongoing climatic change. Altogether, our coupled analyses show that the species is even more threatened than indicated by geospatial analyses alone. Thus, conservation measures that take into account genetic data and the impacts of climate change in the species should be implemented.
... Family 6 comes from a mother tree that had three mature trees at close proximity (less than 50 m), but those trees did not provide pollen as they did not set flowers during the study season. Families 1 and 6 fit well within the suggestion that outcrossing rates and distances among reproductive individuals are negatively associated, with the tendency of geographically isolated trees to become reproductive isolated trees (Rymer et al. 2013;Vinson et al. 2015). ...
Cedrela fissilis is an endangered timber species associated with seasonal forests throughout South America. We investigated a population of C. fissilis (PAN) located toward central Brazil to uncover insights on how an ecotone may have shaped the evolutionary history of this species at the local scale. PAN consisted of 18 mother trees and their 283 offspring (18 families), which were genotyped with ten microsatellite loci. We supplemented our dataset with equivalent microsatellite data from 175 specimens representing the east and west lineages of C. fissilis. An array of complementary methods assessed PAN for genetic diversity, population structure, and mating system. In PAN, the gene pool of the east lineage combined with a third (previously unidentified) lineage to form an admixture population. PAN is under inbreeding (Ho = 0.80 and 0.74, uHe = 0.85 and 0.82, Ap = 1.1 and 7.1, F = 0.06 and 0.10, for mother trees and offspring, respectively). Mother trees were predominantly outcrossing (tm = 0.95), with some selfing (1 − tm = 0.05), and crossing between related individuals (tm–ts = 0.07); they received pollen from few donors (Nep = 9). Restricted gene flow within PAN gave rise to a strong population structure, which split the 18 families into six groups. Some mother trees were reproductively isolated. Conservation perspectives are discussed.
... The ability of at least some SSRs to be transferred across species has facilitated their use in Neotropical tree studies (e.g. Lander et al. 2007;Sebbenn et al. 2011;Caetano et al. 2012;Scotti-Saintagne et al. 2013a, b;Vinson et al. 2015;Mangaravite et al. 2016;Tambarussi et al. 2017). ...
... Finally, seven SSR markers indicated that populations of a critically endangered tree of the Brazilian Savanna, Dimorphandra wilsonii Rizzini (Caesalpinioideae), display low levels of genetic diversity. The authors suggested that monitoring dispersion in order to maintain the genetic diversity and structure is strategy that may ensure the continued survival of this species (Vinson et al. 2015). ...
Genetic analysis provides a robust method for understanding the ways in which human interventions in ecosystems may affect genetic diversity and species survival, providing an empirical basis for evidence-based conservation and management planning. This review aims to (1) describe the most informative and widely-used molecular markers for genotype analysis, and describe the methods for using that genotype data to understand (2) genetic diversity and structure; and (3) mating system, pollen and seed dispersal. For each area of investigation we discuss the types of analyses that can be performed, the software available for the analyses, what the analyses indicate, and provide examples from the literature of studies using these approaches. The review focuses on Neotropical tree species because Neotropical forests are highly diverse, are under particular threat from anthropogenic land-use change, and trees are useful model organisms to investigate patterns over evolutionary time and across geographical space.
... In the field, however, there are many instances in which leaves are not immediately reachs about 30-m tall (Vinson et al. 2015); and C. fissilis reachs up to 45 meters high (Carvalho 1994;. Secondly, plants that occur in the seasoanl dry forest release usually all their leaves in the driest period of the year (Veloso et al. 1991;Oliveira-Filho and Fontes 2000). ...
Bacteria that originate in infections and ailments are known as pathogenic bacteria. When they infiltrate the body, initiate replication, drive out good bacteria, or grow inside the tissues that should be sterile, they generate ailments and infections. Researchers found antibiotic compounds to be the most promising chemotherapeutic agents to cure infective disorders. In the fight against virulent bacteria, new antibiotics are regarded as “drugs of last resort.” However, it is a universal truth that new antibiotics eventually develop resistance. Over the past few decades, dangerous antibiotic-resistant microorganisms have been seen more frequently. However, antibiotic resistance is accelerated through inappropriate use and abuse of currently available antibacterial drugs in the community, vet care, and farming. Tuberculosis, gonorrhoea, pneumonia, wound infections, septicaemia, and a few of diseases like childhood ear infections have become threatening to treat with antibiotics. New medications routinely enter the market alongside existing drugs to address the resistance emerging antagonistic to antibacterial compounds. Additionally, numerous biological and pharmacological processes occurring can be studied and controlled at the nano-scale level, and credit goes to nanotechnology. Recently, antibiotics that have been modified to function as metallic nanoparticles have become a viable platform for overcoming bacterial resistance. Several applications, including targeted drug delivery, bio-sensing, and bio-imaging, are made possible by developing hybrid systems composed of nanoparticles and biological molecules. The present chapter discuss a revised classification and the role of antibacterial medicines based on a review of the literature. The principal groups are classified based on a review of the activity spectrum, top individuals in each class, type of bacteria, source, action, the chemical structure of drugs, and its function used to categorize antibacterial drug-resistant agents and recent advancements of new drug discovery.
Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] is a major timber tree species in China. In the present study, sequence-related amplified polymorphism (SRAP) markers were used to evaluate the polymorphisms, diversity, and relationships in a collection of Chinese fir elite genotypes (n = 103) from the Lechang provenance, an endangered provenance. Thirty-five SRAP primer combinations produced 620 bands among the tested 103 Lechang provenance genotypes and 17 non-Lechang provenance genotypes; 577 (93.1 %) of these were polymorphic, yielding an average of 16.5 polymorphic bands per primer combination. Of the SRAP primer combinations (n = 35), 14 ones identified ≥70.0 % of the 120 genotypes. The Me12–Em19 combination had the strongest discriminatory ability with 93.3 % of the genotypes identified. An UPGMA dendrogram further showed that most of the Lechang provenance genotypes (87.4 %) grouped together (Cluster A). The Lechang genotypes had a considerable amount of genetic variation with genetic similarity from 0.40 to 0.81. The current work may facilitate the management of the endangered Lechang Chinese fir provenance. © 2016 Northeast Forestry University and Springer-Verlag Berlin Heidelberg
