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Benjamin Dauphin - One of the best experts on this subject based on the ideXlab platform.

  • A Worldwide Molecular Phylogeny Provides New Insight on Cryptic Diversity Within the Moonworts (Botrychium s. s., Ophioglossaceae)
    Systematic Botany, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Alessio Maccagni, Jason R. Grant
    Abstract:

    The moonwort genus, Botrychium s. s., includes diploid and polyploid taxa that occur primarily in the northern hemisphere. Their evolutionary history, morphologically cryptic taxa and deep divergence of the family in the phylogeny of ferns has long fascinated pteridologists. Previous molecular studies did not include a complete taxonomic sampling of the taxa in the genus, nor multiple specimens from throughout the known geographical range of each taxon. Therefore, to investigate evolutionary relationships of the major clades of Botrychium s. s., we increased both taxonomic representativeness (multiple accessions per taxa), as well as phylogenetic resolution by including additional new chloroplast markers. To confirm identification and provide evidence from both maternal and paternal parentage of allopolyploids, we also included specimens that have been characterized by allozyme profiles determined by electrophoretic analysis of 20 nuclear enzyme loci for each taxon. We analyzed four chloroplast regions (matK intron, trnHGUG —psbA, andtrnLUAA —trnFGAA intergenic spacers, and rpL16 intron region) of 365 specimens fromAsia, Europe, North America, Oceania, and South America, sampling the geographical range of 34 of 35 accepted Botrychium s. s. taxa and thirteen putatively new taxa. We conducted a phylogenetic analysis of maternal lineages based on 2,385 aligned nucleotides using maximum likelihood and Bayesian inference to explore genetic diversity and phylogenetic relationships among taxa. We found strong support for themonophyly of three major clades: Lanceolatum, Lunaria, and Simplex-Campestre, and resolved 15 subclades. Our results suggest multiple origins for at least four polyploid taxa (B. boreale, B. michiganense, B. yaaxudakeit, and B. watertonense). The Simplex-Campestre clade had the largest number of species, despite having a similar total number of haplotypes as the Lunaria clade (62 and 59, respectively), which has the broadest worldwide distribution. In total, our new molecular phylogeny comprises 47 taxa, of which thirteen are discussed for possible taxonomic recognition.

  • Rapid allopolyploid radiation of moonwort ferns (Botrychium; Ophioglossaceae) revealed by PacBio sequencing of homologous and homeologous nuclear regions.
    Molecular phylogenetics and evolution, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Jason R. Grant, Carl J. Rothfels
    Abstract:

    Polyploidy is a major speciation process in vascular plants, and is postulated to be particularly important in shaping the diversity of extant ferns. However, limitations in the availability of bi-parental markers for ferns have greatly limited phylogenetic investigation of polyploidy in this group. With a large number of allopolyploid species, the genus Botrychium is a classic example in ferns where recurrent polyploidy is postulated to have driven frequent speciation events. Here, we use PacBio sequencing and the PURC bioinformatics pipeline to capture all homeologous or allelic copies of four long (∼1 kb) low-copy nuclear regions from a sample of 45 specimens (25 diploids and 20 polyploids) representing 37 Botrychium taxa, and three outgroups. This sample includes most currently recognized Botrychium species in Europe and North America, and the majority of our specimens were genotyped with co-dominant nuclear allozymes to ensure species identification. We analyzed the sequence data using maximum likelihood (ML) and Bayesian inference (BI) concatenated-data ("gene tree") approaches to explore the relationships among Botrychium species. Finally, we estimated divergence times among Botrychium lineages and inferred the multi-labeled polyploid species tree showing the origins of the polyploid taxa, and their relationships to each other and to their diploid progenitors. We found strong support for the monophyly of the major lineages within Botrychium and identified most of the parental donors of the polyploids; these results largely corroborate earlier morphological and allozyme-based investigations. Each polyploid had at least two distinct homeologs, indicating that all sampled polyploids are likely allopolyploids (rather than autopolyploids). Our divergence-time analyses revealed that these allopolyploid lineages originated recently-within the last two million years-and thus that the genus has undergone a recent radiation, correlated with multiple independent allopolyploidizations across the phylogeny. Also, we found strong parental biases in the formation of allopolyploids, with individual diploid species participating multiple times as either the maternal or paternal donor (but not both). Finally, we discuss the role of polyploidy in the evolutionary history of Botrychium and the interspecific reproductive barriers possibly involved in these parental biases.

  • Ploidy level and genome size variation in the homosporous ferns Botrychium s.l. (Ophioglossaceae)
    Plant Systematics and Evolution, 2016
    Co-Authors: Benjamin Dauphin, Jason Grant, Patrik Mráz
    Abstract:

    Recent cytological and molecular studies have investigated genome size variation and evolution in the homosporous ferns, but representatives of the Ophioglossaceae were largely overlooked, despite their evolutionary singularity. Flow cytometry analysis was performed on 41 individuals of eight species of the genera Botrychium ( B .), Botrypus , and Sceptridium to estimate their ploidy level variation. In a subset of individuals, we also estimated the absolute genome size and corresponding C values. Additionally, a classical chromosome count was made on the recently described species B. alaskense . Ploidy level and new genome size records were determined for Botrychium alaskense , B. boreale , B. lanceolatum , B. “ neolunaria” ined., B. pinnatum , Botrypus virginianus and Sceptridium multifidum. In addition, we confirmed the genome size of B. matricariifolium , B. minganense and B. lunaria. Two of the three major sub-clades of Botrychium differ slightly in their averaged homoploid genome size (subclade Lanceolatum, 24.72 ± 0.40 pg; subclade Lunaria, 27.51 ± 0.47 pg). Flow cytometry and chromosome counting confirmed that B. alaskense is a tetraploid. A new hexaploid cytotype, putatively formed through an autopolyploidization from the sympatric tetraploid cytotype, was detected in a single individual of B. boreale . This is only the second report of hexaploidy in the genus Botrychium and our data highlight the potential to find other ploidy levels within other Botrychium species. Interestingly, no difference within the monoploid genome sizes was detected between ploidy levels, thus supporting the hypothesis of genome size stability after polyploidization and rejecting the scenario of genome downsizing.

  • Molecular phylogenetics supports widespread cryptic species in moonworts (Botrychium s.s., Ophioglossaceae)
    American journal of botany, 2014
    Co-Authors: Benjamin Dauphin, Julien Vieu, Jason R. Grant
    Abstract:

    PREMISE OF THE STUDY Previous phylogenetic studies of moonworts (Botrychium sensu stricto (s.s.)) included few taxa from outside of North America. This low geographical representation limited interpretations of relationships of this group rich in cryptic species. With 18 out of 30 species in the genus being polyploid, understanding their evolutionary history remains a major challenge. METHODS A new molecular phylogeny was reconstructed using Maximum Likelihood (ML) and Bayesian Inference (BI) analyses based on multiple accessions of the most wide-ranging Arctic taxa of Botrychium in North America and Europe using three noncoding plastid DNA regions (psbA-trnH(GUG), trnL(UAA)-trnF(GAA) intergenic spacer, and rpL16 intron). KEY RESULTS The new phylogeny confirms the identity of several recently described species and proposed new taxa. Nine subclades are newly identified within the two major clades in Botrychium s.s.: Lanceolatum and Lunaria. Chloroplast DNA was variable enough to separate morphologically cryptic species in the Lunaria clade. On the contrary, much less variation is seen within the morphologically variable Lanceolatum clade despite sampling over the same broad geographic range. The chloroplast region psbA-trnH(GUG) is identified as an efficient DNA barcode for the identification of cryptic taxa in Botrychium s.s. CONCLUSIONS The combined increase in species representation, samples from throughout the geographic range of each species, and sequencing of multiple plastid DNA regions supports morphologically cryptic species in Botrychium s.s.

Jason R. Grant - One of the best experts on this subject based on the ideXlab platform.

  • A Worldwide Molecular Phylogeny Provides New Insight on Cryptic Diversity Within the Moonworts (Botrychium s. s., Ophioglossaceae)
    Systematic Botany, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Alessio Maccagni, Jason R. Grant
    Abstract:

    The moonwort genus, Botrychium s. s., includes diploid and polyploid taxa that occur primarily in the northern hemisphere. Their evolutionary history, morphologically cryptic taxa and deep divergence of the family in the phylogeny of ferns has long fascinated pteridologists. Previous molecular studies did not include a complete taxonomic sampling of the taxa in the genus, nor multiple specimens from throughout the known geographical range of each taxon. Therefore, to investigate evolutionary relationships of the major clades of Botrychium s. s., we increased both taxonomic representativeness (multiple accessions per taxa), as well as phylogenetic resolution by including additional new chloroplast markers. To confirm identification and provide evidence from both maternal and paternal parentage of allopolyploids, we also included specimens that have been characterized by allozyme profiles determined by electrophoretic analysis of 20 nuclear enzyme loci for each taxon. We analyzed four chloroplast regions (matK intron, trnHGUG —psbA, andtrnLUAA —trnFGAA intergenic spacers, and rpL16 intron region) of 365 specimens fromAsia, Europe, North America, Oceania, and South America, sampling the geographical range of 34 of 35 accepted Botrychium s. s. taxa and thirteen putatively new taxa. We conducted a phylogenetic analysis of maternal lineages based on 2,385 aligned nucleotides using maximum likelihood and Bayesian inference to explore genetic diversity and phylogenetic relationships among taxa. We found strong support for themonophyly of three major clades: Lanceolatum, Lunaria, and Simplex-Campestre, and resolved 15 subclades. Our results suggest multiple origins for at least four polyploid taxa (B. boreale, B. michiganense, B. yaaxudakeit, and B. watertonense). The Simplex-Campestre clade had the largest number of species, despite having a similar total number of haplotypes as the Lunaria clade (62 and 59, respectively), which has the broadest worldwide distribution. In total, our new molecular phylogeny comprises 47 taxa, of which thirteen are discussed for possible taxonomic recognition.

  • Rapid allopolyploid radiation of moonwort ferns (Botrychium; Ophioglossaceae) revealed by PacBio sequencing of homologous and homeologous nuclear regions.
    Molecular phylogenetics and evolution, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Jason R. Grant, Carl J. Rothfels
    Abstract:

    Polyploidy is a major speciation process in vascular plants, and is postulated to be particularly important in shaping the diversity of extant ferns. However, limitations in the availability of bi-parental markers for ferns have greatly limited phylogenetic investigation of polyploidy in this group. With a large number of allopolyploid species, the genus Botrychium is a classic example in ferns where recurrent polyploidy is postulated to have driven frequent speciation events. Here, we use PacBio sequencing and the PURC bioinformatics pipeline to capture all homeologous or allelic copies of four long (∼1 kb) low-copy nuclear regions from a sample of 45 specimens (25 diploids and 20 polyploids) representing 37 Botrychium taxa, and three outgroups. This sample includes most currently recognized Botrychium species in Europe and North America, and the majority of our specimens were genotyped with co-dominant nuclear allozymes to ensure species identification. We analyzed the sequence data using maximum likelihood (ML) and Bayesian inference (BI) concatenated-data ("gene tree") approaches to explore the relationships among Botrychium species. Finally, we estimated divergence times among Botrychium lineages and inferred the multi-labeled polyploid species tree showing the origins of the polyploid taxa, and their relationships to each other and to their diploid progenitors. We found strong support for the monophyly of the major lineages within Botrychium and identified most of the parental donors of the polyploids; these results largely corroborate earlier morphological and allozyme-based investigations. Each polyploid had at least two distinct homeologs, indicating that all sampled polyploids are likely allopolyploids (rather than autopolyploids). Our divergence-time analyses revealed that these allopolyploid lineages originated recently-within the last two million years-and thus that the genus has undergone a recent radiation, correlated with multiple independent allopolyploidizations across the phylogeny. Also, we found strong parental biases in the formation of allopolyploids, with individual diploid species participating multiple times as either the maternal or paternal donor (but not both). Finally, we discuss the role of polyploidy in the evolutionary history of Botrychium and the interspecific reproductive barriers possibly involved in these parental biases.

  • Molecular phylogenetics supports widespread cryptic species in moonworts (Botrychium s.s., Ophioglossaceae)
    American journal of botany, 2014
    Co-Authors: Benjamin Dauphin, Julien Vieu, Jason R. Grant
    Abstract:

    PREMISE OF THE STUDY Previous phylogenetic studies of moonworts (Botrychium sensu stricto (s.s.)) included few taxa from outside of North America. This low geographical representation limited interpretations of relationships of this group rich in cryptic species. With 18 out of 30 species in the genus being polyploid, understanding their evolutionary history remains a major challenge. METHODS A new molecular phylogeny was reconstructed using Maximum Likelihood (ML) and Bayesian Inference (BI) analyses based on multiple accessions of the most wide-ranging Arctic taxa of Botrychium in North America and Europe using three noncoding plastid DNA regions (psbA-trnH(GUG), trnL(UAA)-trnF(GAA) intergenic spacer, and rpL16 intron). KEY RESULTS The new phylogeny confirms the identity of several recently described species and proposed new taxa. Nine subclades are newly identified within the two major clades in Botrychium s.s.: Lanceolatum and Lunaria. Chloroplast DNA was variable enough to separate morphologically cryptic species in the Lunaria clade. On the contrary, much less variation is seen within the morphologically variable Lanceolatum clade despite sampling over the same broad geographic range. The chloroplast region psbA-trnH(GUG) is identified as an efficient DNA barcode for the identification of cryptic taxa in Botrychium s.s. CONCLUSIONS The combined increase in species representation, samples from throughout the geographic range of each species, and sequencing of multiple plastid DNA regions supports morphologically cryptic species in Botrychium s.s.

  • Botrychium alaskense, a New Moonwort from the Interior of Alaska
    American Fern Journal, 2002
    Co-Authors: Warren H. Wagner, Jason R. Grant
    Abstract:

    Abstract Botrychium alaskense W. H. Wagner & J. R. Grant is described as a new species from the interior of Alaska. It is an allotetraploid of B. lunaria (L.) Sw. × B. lanceolatum (S.G. Gmel.) Angstr., the same species parentage that gave rise to the morphologically and isozymically distinct B. pinnatum H. St. John.

Donald R. Farrar - One of the best experts on this subject based on the ideXlab platform.

  • A Worldwide Molecular Phylogeny Provides New Insight on Cryptic Diversity Within the Moonworts (Botrychium s. s., Ophioglossaceae)
    Systematic Botany, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Alessio Maccagni, Jason R. Grant
    Abstract:

    The moonwort genus, Botrychium s. s., includes diploid and polyploid taxa that occur primarily in the northern hemisphere. Their evolutionary history, morphologically cryptic taxa and deep divergence of the family in the phylogeny of ferns has long fascinated pteridologists. Previous molecular studies did not include a complete taxonomic sampling of the taxa in the genus, nor multiple specimens from throughout the known geographical range of each taxon. Therefore, to investigate evolutionary relationships of the major clades of Botrychium s. s., we increased both taxonomic representativeness (multiple accessions per taxa), as well as phylogenetic resolution by including additional new chloroplast markers. To confirm identification and provide evidence from both maternal and paternal parentage of allopolyploids, we also included specimens that have been characterized by allozyme profiles determined by electrophoretic analysis of 20 nuclear enzyme loci for each taxon. We analyzed four chloroplast regions (matK intron, trnHGUG —psbA, andtrnLUAA —trnFGAA intergenic spacers, and rpL16 intron region) of 365 specimens fromAsia, Europe, North America, Oceania, and South America, sampling the geographical range of 34 of 35 accepted Botrychium s. s. taxa and thirteen putatively new taxa. We conducted a phylogenetic analysis of maternal lineages based on 2,385 aligned nucleotides using maximum likelihood and Bayesian inference to explore genetic diversity and phylogenetic relationships among taxa. We found strong support for themonophyly of three major clades: Lanceolatum, Lunaria, and Simplex-Campestre, and resolved 15 subclades. Our results suggest multiple origins for at least four polyploid taxa (B. boreale, B. michiganense, B. yaaxudakeit, and B. watertonense). The Simplex-Campestre clade had the largest number of species, despite having a similar total number of haplotypes as the Lunaria clade (62 and 59, respectively), which has the broadest worldwide distribution. In total, our new molecular phylogeny comprises 47 taxa, of which thirteen are discussed for possible taxonomic recognition.

  • Rapid allopolyploid radiation of moonwort ferns (Botrychium; Ophioglossaceae) revealed by PacBio sequencing of homologous and homeologous nuclear regions.
    Molecular phylogenetics and evolution, 2017
    Co-Authors: Benjamin Dauphin, Donald R. Farrar, Jason R. Grant, Carl J. Rothfels
    Abstract:

    Polyploidy is a major speciation process in vascular plants, and is postulated to be particularly important in shaping the diversity of extant ferns. However, limitations in the availability of bi-parental markers for ferns have greatly limited phylogenetic investigation of polyploidy in this group. With a large number of allopolyploid species, the genus Botrychium is a classic example in ferns where recurrent polyploidy is postulated to have driven frequent speciation events. Here, we use PacBio sequencing and the PURC bioinformatics pipeline to capture all homeologous or allelic copies of four long (∼1 kb) low-copy nuclear regions from a sample of 45 specimens (25 diploids and 20 polyploids) representing 37 Botrychium taxa, and three outgroups. This sample includes most currently recognized Botrychium species in Europe and North America, and the majority of our specimens were genotyped with co-dominant nuclear allozymes to ensure species identification. We analyzed the sequence data using maximum likelihood (ML) and Bayesian inference (BI) concatenated-data ("gene tree") approaches to explore the relationships among Botrychium species. Finally, we estimated divergence times among Botrychium lineages and inferred the multi-labeled polyploid species tree showing the origins of the polyploid taxa, and their relationships to each other and to their diploid progenitors. We found strong support for the monophyly of the major lineages within Botrychium and identified most of the parental donors of the polyploids; these results largely corroborate earlier morphological and allozyme-based investigations. Each polyploid had at least two distinct homeologs, indicating that all sampled polyploids are likely allopolyploids (rather than autopolyploids). Our divergence-time analyses revealed that these allopolyploid lineages originated recently-within the last two million years-and thus that the genus has undergone a recent radiation, correlated with multiple independent allopolyploidizations across the phylogeny. Also, we found strong parental biases in the formation of allopolyploids, with individual diploid species participating multiple times as either the maternal or paternal donor (but not both). Finally, we discuss the role of polyploidy in the evolutionary history of Botrychium and the interspecific reproductive barriers possibly involved in these parental biases.

  • Observations on bipolar disjunctions of moonwort ferns (Botrychium, Ophioglossaceae).
    American journal of botany, 2017
    Co-Authors: Donald R. Farrar, Mary C. Stensvold
    Abstract:

    Peter Raven, in 1963, included two fern taxa of the genus Botrychium in his list of plant species exhibiting American amphitropical bipolar disjunctions. He attributed the southern hemisphere occurrences to post-Pleistocene long-distance dispersal from counterparts in the northern hemisphere, probably assisted by annual bird migrations between the disjunct areas. Using genetic evidence gathered through worldwide analyses of phylogenetic relationship in Botrychium, we now review and reconsider Raven's conclusions. Genetic similarities indicate that South American Botrychium dusenii is an allotetraploid taxon closely related to B. spathulatum, a North American endemic, and that B. lunaria in New Zealand possesses a genotype identical to that of a taxon in North America derived through introgressive hybridization between B. lunaria and an endemic North American species, B. neolunaria. Both North American counterparts exhibit Raven's characteristics of bipolar disjuncts in their occurrence in mountain and coastal meadows, copious production of small propagules (spores in Botrychium), occurrence in habitats frequented by transpolar bird migrants, and ability to found new colonies through inbreeding. We discuss these characteristics in Botrychium and relative to other ferns and suggest further studies on Botrychium and related taxa to address questions of time, number, and mode of bipolar dispersals.

  • Relationships in the Botrychium campestre (Ophioglossaceae) complex
    Brittonia, 2017
    Co-Authors: Donald R. Farrar, Arthur V. Gilman
    Abstract:

    Botrychium campestre and B. lineare have, since their original descriptions, been considered closely related due to their morphological similarity. Although B. lineare was initially thought to be very rare, subsequent discoveries of many additional populations, especially in the Rocky Mountains and Sierra ranges, have afforded the opportunity to analyze hundreds of specimens on the basis of allozyme genetics. Surprisingly, B. lineare demonstrates a high degree of heterozygosity, implying an outcrossing breeding system, unlike the mostly homozygous, selfing B. campestre . However, overall levels of Nei’s Genetic Identity between the two taxa are higher than usual between species. With this knowledge, we infer that taxon lineare is probably ancestral within complex, and that taxon campestre arose from within it as an adaptation to more xeric habitats. Given that B. campestre has nomenclatural priority, we propose to recognize lineare as a variety within a more broadly construed campestre , i.e., Botrychium campestre var. lineare, and suggest that hybrid or introgressed plants, such as rarely occur (e.g., at Glacier National Park and in the Black Hills of South Dakota) be referred to only at the specific rank, i.e., without reference to variety

  • Botrychium ascendens W. H. Wagner (Ophioglossaceae) in Newfoundland and Notes on its Origin
    American Fern Journal, 2009
    Co-Authors: Peter F. Zika, Donald R. Farrar
    Abstract:

    Abstract Botrychium ascendens is reported from Fogo Island in Newfoundland as an addition to the flora of the province. Fogo Island plants are identical to plants in western North America, including those from the type locality, in comparisons of leaf morphology, spore size, and allozyme expression. Comparisons are made with related and confusing taxa, B. campestre, B. crenulatum, B. lineare, and the American genotype of B. lunaria. Newfoundland plants display a high level of fixed heterozygosity and large spore size, indicating they are allotetraploid, and supporting suggestions that B. ascendens is derived from ancient hybridization between B. crenulatum and the B. lineare/campestre complex. The current distribution of Botrychium ascendens and its putative parents suggest it probably originated in western North America and migrated across northern Canada to Newfoundland.

Warren D. Hauk - One of the best experts on this subject based on the ideXlab platform.

  • A Phylogenetic Investigation of Botrychium s. s. (Ophioglossaceae): Evidence from Three Plastid DNA Sequence Datasets
    Systematic Botany, 2012
    Co-Authors: Warren D. Hauk, Larkin Kennedy, Heather M. Hawke
    Abstract:

    Abstract Phylogenetic relationships among 23 species of Botrychium s. s. were investigated using sequence data from three plastid DNA regions: rbcL, trnLUAA -trnFGAA intergenic spacer, and rpL16 intron. Individual and combined maximum parsimony and a combined maximum likelihood analysis showed strong support for the monophyly of Botrychium s. s., and all analyses identified three main, well-supported clades. However, within those three clades all analyses did not produce identical tree topologies. The Lanceolatum clade contained the diploid B. lanceolatum and seven polyploids, the Lunaria clade contained the diploids B. lunaria and B. crenulatum, and the Simplex-Campestre clade contained 13 species distributed across five subclades. Relationships among the five subclades were not resolved in either of the combined analyses. The Simplex subclade contained four diploids (B. simplex, B. montanum, B. mormo, and B. pumicola), the Pallidum subclade contained the diploid B. pallidum and the tetraploid B. gallico...

  • Phylogenetic studies of Ophioglossaceae: evidence from rbcL and trnL-F plastid DNA sequences and morphology
    Molecular phylogenetics and evolution, 2003
    Co-Authors: Warren D. Hauk, Clifford R. Parks, Mark W. Chase
    Abstract:

    Ophioglossaceae are a putatively ancient lineage of ferns in which the aerial portion of the plant is composed of a single leaf. The simplicity of foliar morphology has limited the number of characters available for constructing classifications and contributed to taxonomic difficulties at nearly every level of classification within the family. Analysis of plastid DNA rbcL sequences from 36 species representing the diversity of Ophioglossaceae supported the monophyly of the family. Intrafamilial relationships were examined using rbcL and trnL-F plastid DNA sequences and morphological data. Individual and combined analyses of the three data sets revealed two main clades within the family, here termed ophioglossoid and botrychioid. In the botrychioid clade, Helminthostachys was sister to a broadly defined Botrychium, within which Botrychium in the narrow sense of some authors and Sceptridium were sister. Botrypus was paraphyletic, with Botrypus virginianus sister to Botrychium plus Sceptridium, and with Botrypus strictus sister to all other botrychioid species except Helminthostachys. In the ophioglossoid clade, Ophioglossum in the narrow sense was sister to Cheiroglossa plus Ophioderma, but relationships within Ophioglossum were not well supported.

  • Isozyme variability among cryptic species of Botrychium subgenus Botrychium (Ophioglossaceae)
    American journal of botany, 1999
    Co-Authors: Warren D. Hauk, Christopher H. Haufler
    Abstract:

    The systematics of Botrychium subgenus Botrychium has been controversial, primarily because reduction in frond size and complexity has limited the number of characters available for discrimination of species. The recognition of many polyploid species has magnified the difficulty of classification because allopolyploids are often morphologically intermediate between their progenitor diploids. In order to evaluate species limits and sectional boundaries, we surveyed and compared 16 of the 24 currently recognized species for isozymic variation. Little or no intrapopulational variation was detected, but the variation present was consistent with the hypothesis that Botrychium species are primarily inbreeding. Interspecific comparisons distinguished six diploid species and provided evidence of molecular differentiation between the cryptic sister species B. lunaria and B. crenulatum. Evidence of possible progenitor/descendant relationships was found for certain diploid/ polyploid relationships. Using enzyme bands shared between species, realignment of the sectional assignment of several species is proposed. Anomalous banding patterns in certain individuals suggested that gene silencing or homoeologous chromosome pairing might be operating in B. minganense, B. hesperium,and B. matricariifolium. Isozyme data also showed that some populations of species presumed to be uniformly diploid possessed isozyme patterns typical of polyploids. All available molecular data indicate that members of Botrychium subgenus Botrychium are actively evolving at diploid and polyploid levels.

  • A Molecular Assessment of Relationships Among Cryptic Species of Botrychium Subgenus Botrychium (Ophioglossaceae)
    American Fern Journal, 1995
    Co-Authors: Warren D. Hauk
    Abstract:

    Phylogenetic relationships among 20 currently recognized species of Botrychium sub- genus Botrychium were investigated using nucleotide sequences from the plastid gene rbcL. Anal- ysis of eight diploid species produced a single most parsimonious tree with three distinct clades. The lanceolatum clade (one species) was sister to all other species. The lunaria clade (two species) was sister to the simplex-campestre clade (five species) which contained two weakly supported subclades. Single populations of B. lunaria and B. simplex were more closely related to other species in the same geographic region than to populations of their own species from distant geo- graphic regions. In a second analysis that included both diploid and polyploid species, eight of twelve polyploid taxa had rbcL sequences identical to those of known diploids, which suggested relatively recent origins for these eight polyploid species. Four polyploids, B. ascendens, B. par- adoxum, B. Xwatertonense, and B. minganense, did not associate with a diploid species, and therefore represented polyploid derivatives of diploid taxa that were not sampled and possibly are extinct. Associations of diploid and polyploid species as determined by rbcL analysis are consistent with morphological hypotheses of polyploid origins with the exception of B. ascendens, which did not possess the rbcL sequence of either of its putative diploid progenitors. Species of Botrychium subgenus Botrychium, commonly called moonworts,

Choudhury Jayanta - One of the best experts on this subject based on the ideXlab platform.

  • Morfološke razlike plodnih izrastkov na sporo-trofofilu vrste Helminthostachys zeylanica (L.) Hook
    ZRC SAZU Založba ZRC, 2015
    Co-Authors: Chakraborty, Tapas K., Chaudhuri, Sandip Dev, Choudhury Jayanta
    Abstract:

    The evolutionary history of Ophioglossaceae is enigmatic mainly because fossils of the family trace back only from the earliest Tertiary. Phylogenetic analyses indicate that Helminthostachys is sister to the broadly defined Botrychium. Generally the sporophore of Botrychium is a pinnately compound, whereas it is simple in Helminthostachys. Here examples of different Helminthoistachys are represented which show double or triple spikes with some variations. Plants showing variations in their spike morphology are also grown normally. Variations of Helminthostachys spike morphology indicate a tendency to form a compound sporophore structure and in that way have a strong relationship with Botrychium.Evolucijski razvoj družine kačjejezikovk (Ophioglossaceae) je precej skrivnosten, saj prve fosilne ostanke predstavnikov družine najdemo šele iz zgodnjega terciarja. Filogenetske raziskave kažejo, da je monotipični rod Helminthostachys sestrski sicer širše definiranemu rodu mladomesečin (Botrychium). Na splošno je fertilni ali plodni del sporotrofofila pri rodu Botrychium pernato deljen, medtem ko je pri rodu Helminthostachys valjast in enostaven. V študiji so predstavljeni različni osebki vrste Helminthostachys zeylanica z enim ali več plodnimi izrastki. Osebki, ki kažejo na variacijo v obliki trosnih izrastkov rastejo v naravnem okolju. Različna morfologija plodnega-trosnega dela sporotrofofila pri rodu Helminthostachys nakazuje tendenco k tvorbi pernato deljenih trosnih izrastkov, kar je znak sorodnosti omenjenega rodu z rodom Botrychium