Gerald J. Gastony's research while affiliated with Indiana University Bloomington and other places
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Publications (51)
Abstract— Strong selective pressures imposed by drought-prone habitats have contributed to extensive morphological convergence among the 400 + species of cheilanthoid ferns (Pteridaceae). As a result, generic circumscriptions based exclusively on macromorphology often prove to be non-monophyletic. Ongoing molecular phylogenetic analyses are providi...
Species of the dicksonioid genus Cibotium occur in the Hawaiian Islands, Central America – Mexico, and Southeast Asia – Western Malaysia. All investigated specimens produce 64-spored sporangia and the sodium hydroxide assay demonstrates a more or less granular perine deposition over the exine in mature or slightly immature spores. This perine form...
Gametophyte morphologies and gametangial sequences in agar cultures of Bommeria species indicated developmental control by an antheridiogen system. The first gametophytes to develop were meristematic and archegonial with ameristic, exclusively antheridial plants appearing later in the same cultures. Bommeria gametophytes were found to form precocio...
Nucleotide sequences of the chloroplast-encoded rbcL gene were determined for Loxoscaphe thecifera and Actiniopteris radiata and used in maximum parsimony cladistic analyses to determine their phylogenetic positions in the context of a broad range of advanced fern taxa. Loxoscaphe nested firmly within the Aspleniaceae, and Actiniopteris was placed...
Four members of the alpha-tubulin gene family were examined in Ceratopteris richardii. Genetic linkage mapping based on a population of nearly 500 Doubled Haploid Lines was able to position three or four members of this gene family on linkage groups 17, 24, and 28, respectively (two of the four observed polymorphic restriction fragments containing...
Cheilanthoid ferns (Pteridaceae) are a diverse and ecologically important clade, unusual among ferns for their ability to colonize and diversify within xeric habitats. These extreme habitats are thought to drive the extensive evolutionary convergence, and thus morphological homoplasy, that has long thwarted a natural classification of cheilanthoid...
Introduction Analyses of gene expression and function, genetic networks, population polymorphisms, and genome organization at the whole genome level have enabled research on previously intractable questions (reviewed in Wolfe and Li, 2003). Among plant lineages, genomic approaches have been most widely applied in the angiosperms, where significant...
Biological factors involved in reproductive barriers between two divergent races of Ceratopteris richardii were investigated. We used a combination of spore germination rates, QTL analysis of spore germination rates, and transmission ratio distortion (TRD) of 729 RFLPs, AFLPs, and isozyme markers distributed across the genome on the basis of hybrid...
Homosporous ferns have extremely high chromosome numbers relative to flowering plants, but the species with the lowest chromosome numbers show gene expression patterns typical of diploid organisms, suggesting that they may be diploidized ancient polyploids. To investigate the role of polyploidy in fern genome evolution, and to provide permanent gen...
Genetic linkage mapping based on RFLPs is a valuable genomics tool for studying organisms with no genome sequence information.
However, the generally used Southern hybridization method based on the radioisotope32P is not ideal for genotyping large mapping populations. We have overcome limitations of the alternative chemiluminescent
detection system...
Species of the genus Sullivantia contain quercetin 3-β-D-galactoside, pedalitin and its 6-β-D-glucoside as well as the new glycosides quercetin 3-galactosyl-glucuronoside and pedalitin 6-galactosylglucoside. A pedalitin 6-galactosyl compound was also found. An additional compound was identified as quercetin 3-x″-(galactosyl)-x″-(glucuronosyl)-glucu...
Anogramma is a genus of eight putative species with small annual sporophytes and potentially perennating gametophytes. Phylogenetic relationships within the genus as well as its relationships with other putatively taenitidoid genera and with traditionally cheilanthoid Cosentinia vellea have been poorly resolved and are investigated here. Maximum pa...
Nucleotide sequences of the chloroplast-encoded rbcL gene were determined for all five species of the onocleoid ferns (Dryopteridaceae tribe Onocleeae), including both varieties of Onoclea sensibilis, and for outgroup member Blechnum glandulosum. Together with GenBank sequences of three additional onocleoid accessions and four additional taxa repre...
We analyzed nucleotide variation in rbcL (the gene encoding the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase) from 99 genera of leptosporangiate ferns representing 31 of the 33 extant families. Phylogenetic relationships were inferred using three methods: neighbor joining, maximum parsimony, and maximum likelihood. All three met...
The cheilanthoid ferns have long resisted efforts to circumscribe well-defined, phylogenetically natural generic and infrageneric groups, presumably because of homoplastic morphologies associated with their xeric habitats. This cladistic analysis of phylogenetically informative chloroplast DNA restriction site data from 14 enzymes and seven taxa in...
The cheilanthoid ferns have long resisted efforts to circumscribe well-defined, phylogenetically natural generic and infrageneric groups, presumably because of homoplastic morphologies associated with their xeric habitats. This cladistic analysis of phylogenetically informative chloroplast DNA restriction site data from 14 enzymes and seven taxa in...
Molecular data from the chloroplast genome are being used to reconstruct the phylogeny and revise the problematic taxonomy of the xerically adapted cheilanthoid ferns. Chloroplast DNA based phylogenies trace maternal, paternal, or biparental lineages, depending on the mode of inheritance of the chloroplast genome, and instances of all three modes o...
Molecular data from the chloroplast genome are being used to reconstruct the phylogeny and revise the problematic taxonomy of the xerically adapted cheilanthoid ferns. Chloroplast DNA based phylogenies trace maternal, paternal, or biparental lineages, depending on the mode of inheritance of the chloroplast genome, and instances of all three modes o...
Because of their high chromosome numbers, homosporous vascular plants were considered paleopolyploids until recent enzyme electrophoretic studies rejected this hypothesis by showing that they express only diploid numbers of isozymes. In polyploid sporophytes of the homosporous fern pelleae rufa, however, progressive diminution of phosphoglucoisomer...
Pellaea rufa is a sexually reproducing tetraploid species with a chromosome number of n = 58 II at meiosis. Unlike previously reported tetraploid ferns, sporophytes of P. rufa exhibit substantial intrapopulational electrophoretic variation for respective enzyme phenotypes, and many of their heterozygous phenotypes are segregating rather than fixed....
Restriction site mutations in the chloroplast DNAs from members of the fern genus, Phanerophlebia, and some representatives of Cyrtomium and Polystichum were used to elucidate phylogenetic relationships within and between these groups. Evidence is presented against the hypothesis that Phanerophlebia was derived from Cyrtomium; rather the two genera...
Restriction site variation in chloroplast DNA was examined in the neotropical fern genus Phanerophlebia and in selected species of the related Asiatic genus Cyrtomium and the cosmopolitan progenitor of these two, Polystichum. A total of 103 restriction site mutations was identified; these were used to construct phylogenetic networks and trees based...
Genetic relationships among the seven species of Agastache sect. Agastache common in North America and the one found in eastern Asia were assessed using starch-gel electrophoresis of twelve enzymatic proteins. Nei's (1976) genetic distance and identity values, calculated among the 32 populations used in this study, partitioned the Agastache section...
Agastache sect. Agastache consists of seven species in North America and one disjunct in eastern Asia. Starch-gel electrophoresis of enzymatic proteins was employed to assess genetic relationships among these species and to estimate the amount of genetic divergence between the North American and Asian populations. Species of the western United Stat...
Allopolyploid speciation is well documented in the ferns, but data from enzyme electrophoresis have only recently shown that certain sexual and agamosporous taxa are autopolyploids. Autopolyploidy may arise through fertilization involving gametophytes from unreduced spores, a mechanism previously proposed to account for the origin of allopolyploid...
Genetic variability was examined in nine sexual and three apogamous natural populations ofthe homosporous fern Pellaea andromedifolia by electrophoretic analysis of enzymes specified by eight loci. Genetic interpretations of heterozygous banding patterns were determined by segregational analysis of gametophytes. High levels of segregating heterozyg...
Genetic variability was examined in nine sexual and three apogamous natural populations of the homosporous fern Pellaea andromedifolia by electrophoretic analysis of enzymes specified by eight loci. Genetic interpretations of heterozygous banding patterns were determined by segregational analysis of gametophytes. High levels of segregating heterozy...
Intact chloroplasts isolated from mature leaf tissue of the homosporous fern Athyrium filixfemina were osmotically ruptured and subjected to starch gel electrophoresis in side by side comparisons with whole leaf extracts. The single enzyme activities of reportedly cytosolic [NADP]IDH and [NADP]ME were not expressed in the chloroplast fraction, and...
Homosporous fern sporophytes from natural populations exhibited heterozygous electrophoretic patterns for several enzyme systems. Genetic tests utilizing individual gametophytes demonstrate that the observed heterozygosity is coded by alleles at single loci. This simple procedure makes it possible to distinguish segregating from fixed or phenotypic...
The most mature spores available in herbarium specimens of the dicksoniaceous genera Cystodium, Thyrsopteris, and Culcita were studied by scanning electron microscopy and light microscopy, and representative specimens were analyzed to determine the number of spores produced per sporangium. Thyrsopteris and Culcita feature 64-spored sporangia, but C...
Although numerous flowering plant species have been subjected to electrophoretic enzyme analysis, very few such studies have involved pteridophytes. This is largely because standard methodology typically results in little or no electrophoretically detectable enzymatic activity in pteridophytes. The presence of large amounts of phenolic compounds in...
Light and scanning electron microscopy of spores was used to examine exospore and perispore characters in Bommeria and related fern genera. All Bommeria species were found to possess a smooth exospore surface which offered no taxonomically significant variation. Perispore features, however, separate Bommeria species into two groups, one having a cr...
Scanning electron microscopy supported by light microscopic L-O analysis is used in a palynological study of the genus Trichipteris of the tree fern family Cyatheaceae. The spores of all but two of the 55 species are investigated and the results are related to previous findings for Trichipteris species in the literature. A perine layer consisting o...
Scanning electron microscopy and transmitted light microscopy are used in a palynological study of Lophosoria, Metaxya, Sphaeropteris, Alsophila, and Nephelea of the tree fern family Cyatheaceae. The monotypic American genera Lophosoria and Metaxya each have a unique spore morphology which reinforces the taxonomic distinctness of these genera as in...
Species of the fern genus Bommeria occur from the southwestern United States, throughout much of Mexico and into Guatemala, Honduras, Nicaragua and Costa Rica. Acetocarmine squashes of spore mother cells, root tips, and gametophyte meristems have yielded chromosome counts for the five putative species: n = 30, 2n = 60 in B. hispida (Mett.) Underw.,...
The literature on cyatheaceous spore morphology relative to the presence of a perine layer is reviewed, and evidence based on a sodium-hydroxide assay is presented indicating that the outer scultpine layer in certain cyatheaceous spores is perine. Perine so defined characterizes Metaxya, paleotropical and certain neotropical species of Sphaeropteri...
Citations
... The vast majority of DNA-based studies of fern phylogeny and evolution to date have used primarily or exclusively plastid loci (e.g., Pryer et al., 2001Pryer et al., , 2004Schuettpelz and Pryer, 2007;Testo and Sundue, 2016; see Table 1 in Rothfels et al., 2015 for a summary of the main studies in deep fern phylogenetics), which act as a single linkage group (Lynch, 2007) and are maternally inherited in ferns (Gastony and Yatskievych, 1992;Vogel et al., 1998;Guillon and Raquin, 2000;Kuo et al., 2018b). Nuclear analyses of fern phylogenetics, in contrast, have lagged behind and have focused on just a few loci. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/277931373940739-1443275411242_Q64/George-Yatskievych.jpg)
... During the 1980s, studies that used variation for restriction sites in chloroplast DNA provided considerable resolution of relationships among closely related species, usually within genera (Gastony et al. 1992, Conant et al. 1994. However, broader-scale relationships were not resolved until a further technical advance in molecular biology. ...
Reference: Unfurling Fern Biology in the Genomics Age
... Note:-Gymnosphaera khasyana was sampled in molecular analyses and was confirmed to be a member of Gymnosphaera (Dong & Zuo 2018). Gastony (1974), however, reported 16 spores per sporangium in G. khasyana. Gastony's report was based on the collection Dickason 9247 (US) (erroneously printed as 9347), which is actually a collection of Alsophila costularis characterized by hairs present on abaxial surface of costa and costule. ...
Reference: Synopsis of Cyatheaceae from Myanmar
... Therefore, 32 spores per sporangium were considered to be presumptive evidence of apomictic ferns [29,30,32]. However, some species have been confirmed to be sexually reproductive ferns, even though they have 32 spores, such as Lindsaeaceae species [33] and Cystodium sorbifolium [34], or 16 spores, such as Alsophila species [35]. Lin, Kato, and Iwatsuki [34] deduced that the formation of eight spore mother cells was due to the reduction in premeiotic mitosis divisions from four to three and referred to these species types as "32-spored sexual type" or "lindsaeoid type". ...
... In homosporous ferns, this analysis is relatively straightforward because gametophytes are multicellular, mitotic derivatives of single, meiotically produced spores. These gametophytes can be analyzed individually by electrophoresis similar to the case for pollen of angiosperms (10), and studies have been carried out in several fern species (11,12). Using these and other (13) established procedures, we examined a representative set of homosporous ferns (Table 1). ...
... Around the same time, work also began on homosporous fern genetics (Lang, 1923;Andersson-Kottö, 1927, 1929, 1938. These initial studies provided the first chromosome counts and crossing experiments in ferns; importantly, they presented the theory that ferns with high chromosome numbers had diploid, not polyploid, inheritance (Andersson-Kottö, 1929, 1938Haufler, 2002). ...
Reference: Book Chapter
... Support for the 'ancient polyploid' hypothesis had largely eroded by the late 1990s. Evidence that challenged this theory included isozyme and genetic studies that showed homosporous ferns with the base chromosome numbers for their genera (even if those numbers were high) to have diploid expression profiles (Gastony & Darrow, 1983;Gastony & Gottlieb, 1985;Haufler, 1985Haufler, , 1987Haufler & Soltis, 1986;Soltis, 1986;Soltis & Soltis, 1986Werth, Guttman, & Eshbaugh, 1985) and disomic inheritance patterns (Gastony & Gottlieb, 1982, 1985Haufler & Soltis, 1984;Wolf, Haufler, & Sheffield, 1987). In addition, while studies of fern breeding systems found several homosporous species to be capable of gametophytic selfing (eg, Holbrook-Walker & Lloyd, 1973;Klekowski, 1969;Lloyd, 1973;Werth et al., 1985), most species were found either to have mixed mating systems or to be predominantly outcrossing (Holsinger, 1987;reviewed in Sessa et al., in review). ...
... Furthermore, Deltoidospora adriennis has been considered to correspond to the present-day fresh and brackish water fern Acrostichum aureum (mangrove fern), which is typical of the inner mangrove zone, especially in more open and disturbed areas (van der Hammen 1963; Ellison 1989; Westgate and Gee 1990; Rull 1998). However, some tree ferns from tropical rain forests, like the Cyatheaceae, are also recognized to have spores with the same morphology (Murillo and Bless 1974;Gastony and Tryon 1976). According to Rull (1997), sediments from fern swamps are dominated by Polypodium spores, that are morphologically similar to Verrucatosporites and Laevigatosporites. ...
... Muchos trabajos palinológicos han sido de gran utilidad para la delimitación de familias, géneros y especies (Kremp & Kawasaki 1972, Tryon & Lugardon 1991 por ejemplo: Cystopteris (Hagenah 1961), Thelypteridaceae (Wood 1973), Cheilanthes (Knobloch 1969, Notholaena (Devi et al. 1971), Anemia (Hill 1977(Hill , 1979 y Serpocaulon (Ramírez-Valencia et al. 2013). Distintos autores han elaborado descripciones detalladas de las esporas de distintos grupos de helechos y licofitas, lo que ha servido en la reconstrucción filogenética de los mismos, como es el caso de Cheilanthes , Cyatheaceae (Gastony 1979), Polypodium (Lloyd 1981), Marsileaceae (Schneider & Pryer 2002), Selaginellaceae (Korall & Taylor 2006), Elaphoglossum , Lomariopsis , Leucothrichum (Labiak et al. 2010), Lindsaeaeceae (Lehtonen et al. 2010), Serpocaulon (Ramírez-Valencia & Sanín 2017) y Pteris (Chao & Huang 2018), entre otros. ...
... Deviations from standard sporogenesis that result in unreduced (n = 2n) spores are well documented in ferns, forming obligately in some species and facultatively in others (Steil, 1919;Döpp, 1932;Manton, 1950;Braithwaite, 1964;Evans, 1964;Morzenti, 1967;Haufler et al., 1985;Walker, 1985;Gastony, 1986;Gastony and Windham, 1989). In some cases, unreduced spores (n = 2n) can be found intermixed with canonically derived haploid (n) spores from separate sporangia on the same plant ( Fig. 1), or even within the same sporangium (Mehra and Bir, 1960;Knobloch, 1966Knobloch, , 1969Tryon, 1968;Debenedictis, 1969;Brouharmont, 1972a, b;Lloyd, 1973;Lin et al., 1992;Rabe and Haufler, 1992;Sigel et al., 2011;Ekrt and Koutecky, 2016;Wickell et al., 2017). ...
