scholarly journals Mining transcriptomic data to study the origins and evolution of a plant allopolyploid complex

2014 ◽  
Author(s):  
Aureliano Bombarely ◽  
Jeremy E Coate ◽  
Jeff J Doyle
Keyword(s):  
Population Genomics ◽  
Transcriptome Assembly ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
Complex Problem ◽  
Common Mechanism ◽  
Chromosome Loss ◽  
Polyploid Species ◽  
Multiple Origins ◽  
Cultivated Soybean

Allopolyploidy combines two progenitor genomes in the same nucleus, and is a common mechanism for producing new species, especially in plants. Deciphering the origins of polyploid species is a complex problem, due to, among other things, extinct progenitors, multiple origins, gene flow between different polyploid populations, and loss of parental contributions through gene or chromosome loss. In this work, we studied three allopolyploid species in the genus Glycine, which includes the cultivated soybean (G. max). Previous work based on two nuclear sequences showed that these allopolyploids combine the genomes of extant diploid species in the G. tomentella complex. We use several phylogenetic and population genomics approaches to clarify the origin of these species using single nucleotide polymorphism data and a guided transcriptome assembly. The results support the hypothesis that each of the three polyploid species are fixed hybrids combining the homoeologous genomes of its two putative parents. Based on mapping to the soybean reference genome, there appear to be no large regions for which one homoeologous contribution is missing. Phylogenetic analyses of 27 selected transcripts using a coalescent approach also indicates multiple origins for G. tomentella polyploid species, and suggest that origins occurred within the last several hundred thousands years.

scholarly journals Mining transcriptomic data to study the origins and evolution of a plant allopolyploid complex

2014 ◽  
Author(s):  
Aureliano Bombarely ◽  
Jeremy E Coate ◽  
Jeff J Doyle
Keyword(s):  
Population Genomics ◽  
Transcriptome Assembly ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
Complex Problem ◽  
Common Mechanism ◽  
Chromosome Loss ◽  
Polyploid Species ◽  
Multiple Origins ◽  
Cultivated Soybean

Allopolyploidy combines two progenitor genomes in the same nucleus, and is a common mechanism for producing new species, especially in plants. Deciphering the origins of polyploid species is a complex problem, due to, among other things, extinct progenitors, multiple origins, gene flow between different polyploid populations, and loss of parental contributions through gene or chromosome loss. In this work, we studied three allopolyploid species in the genus Glycine, which includes the cultivated soybean (G. max). Previous work based on two nuclear sequences showed that these allopolyploids combine the genomes of extant diploid species in the G. tomentella complex. We use several phylogenetic and population genomics approaches to clarify the origin of these species using single nucleotide polymorphism data and a guided transcriptome assembly. The results support the hypothesis that each of the three polyploid species are fixed hybrids combining the homoeologous genomes of its two putative parents. Based on mapping to the soybean reference genome, there appear to be no large regions for which one homoeologous contribution is missing. Phylogenetic analyses of 27 selected transcripts using a coalescent approach also indicates multiple origins for G. tomentella polyploid species, and suggest that origins occurred within the last several hundred thousands years.

scholarly journals Chloroplast phylogenomics in Camelina (Brassicaceae) reveals multiple origins of polyploid species and the maternal lineage of C. sativa

2022 ◽  
Vol 9 ◽  
Author(s):  
Jordan R Brock ◽  
Terezie Mandáková ◽  
Michael McKain ◽  
Martin A Lysak ◽  
Kenneth M Olsen
Keyword(s):  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Diploid Species ◽  
Time Estimation ◽  
Polyploid Species ◽  
Chromosome Counts ◽  
Diploid Parent ◽  
Divergence Time Estimation ◽  
Multiple Origins ◽  
Chloroplast Genomes

Abstract The genus Camelina (Brassicaceae) comprises 7–8 diploid, tetraploid, and hexaploid species. Of particular agricultural interest is the biofuel crop, C. sativa (gold-of-pleasure or false flax), an allohexaploid domesticated from the widespread weed, C. microcarpa. Recent cytogenetics and genomics work has uncovered the identity of the parental diploid species involved in ancient polyploidization events in Camelina. However, little is known about the maternal subgenome ancestry of contemporary polyploid species. To determine the diploid maternal contributors of polyploid Camelina lineages, we sequenced and assembled 84 Camelina chloroplast genomes for phylogenetic analysis. Divergence time estimation was used to infer the timing of polyploidization events. Chromosome counts were also determined for 82 individuals to assess ploidy and cytotypic variation. Chloroplast genomes showed minimal divergence across the genus, with no observed gene-loss or structural variation. Phylogenetic analyses revealed C. hispida as a maternal diploid parent to the allotetraploid Camelina rumelica, and C. neglecta as the closest extant diploid contributor to the allohexaploids C. microcarpa and C. sativa. The tetraploid C. rumelica appears to have evolved through multiple independent hybridization events. Divergence times for polyploid lineages closely related to C. sativa were all inferred to be very recent, at only ~65 thousand years ago. Chromosome counts confirm that there are two distinct cytotypes within C. microcarpa (2n = 38 and 2n = 40). Based on these findings and other recent research, we propose a model of Camelina subgenome relationships representing our current understanding of the hybridization and polyploidization history of this recently-diverged genus.

Polyphyletic origins of Brassica napus: new evidence based on organelle and nuclear RFLP analyses

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 992-1001 ◽  
Author(s):  
Keming Song ◽  
Thomas C. Osborn
Keyword(s):  
Brassica Napus ◽  
Phylogenetic Analyses ◽  
Molecular Taxonomy ◽  
Diploid Species ◽  
Evidence Based ◽  
Diploid Progenitor ◽  
Multiple Origins ◽  
Specialized Form ◽  
Almost All ◽  
New Evidence

Accessions representing a range of diversity in Brassica napus and their potential diploid progenitor species were analyzed using nuclear, chloroplast (ct), and mitochondrial (mt) RFLPs. Based on RFLPs of ctDNA and mtDNA, cytoplasmic genomes of the diploid species examined could be classified into four major types, represented by almost all B. rapa, Broccoletto (a specialized form of B. rapa), B. oleracea, and B. montana. Results from phylogenetic analyses of these data suggest that B. montana might be closely related to the prototype that gave rise to both cytoplasms of B. rapa and B. oleracea. The four major types of cytoplasms found in the diploid species were also observed in B. napus accessions. A majority of the cultivated B. napus examined contained a cytoplasm different from those of either B. rapa and B. oleracea. These B. napus accessions (designated M/N cytoplasm type) had the same chloroplast genome as that of B. montana and a unique mitochondrial genome that was somewhat intermediate between those of B. montana and B. rapa. These results strongly support the concept of multiple origins of B. napus and provide the first evidence that most cultivated forms of B. napus were derived from a cross in which a closely related ancestral species of B. rapa and B. oleracea was the maternal donor. Phylogenetic relationships based on nuclear RFLPs clearly separated B. napus accessions having different cytoplasm types, providing further evidence for multiple origins of B. napus. Brassica napus accessions having M/N type cytoplasm were clustered together as three subgroups: one contained oilseed cultivars from Canada, a second contained oilseed cultivars from Europe, and a third contained accessions of rutabaga.Key words: Brassica napus, molecular taxonomy, RFLP, chloroplast, mitochondrion.

scholarly journals Chloroplast Phylogenomic Analyses Resolve Multiple Origins of the Kengyilia Species (Poaceae: Triticeae) via Independent Polyploidization Events

2021 ◽  
Vol 12 ◽  
Author(s):  
Shiyong Chen ◽  
Hao Yan ◽  
Lina Sha ◽  
Ning Chen ◽  
Haiqin Zhang ◽  
...  
Keyword(s):  
Diploid Species ◽  
Sequence Divergence ◽  
Phylogenomic Analysis ◽  
Polyploid Species ◽  
Genome Doubling ◽  
Multiple Origins ◽  
Rich Diversity ◽  
Wide Adaptation ◽  
The Rich ◽  
Phylogenomic Analyses

Kengyilia is a group of allohexaploid species that arose from two hybridization events followed by genome doubling of three ancestral diploid species with different genomes St, Y, and P in the Triticeae. Estimating the phylogenetic relationship in resolution of the maternal lineages has been difficult, owing to the extremely low rate of sequence divergence. Here, phylogenetic reconstructions based on the plastome sequences were used to explore the role of maternal progenitors in the establishment of Kengyilia polyploid species. The plastome sequences of 11 Kengyilia species were analyzed together with 12 tetraploid species (PP, StP, and StY) and 33 diploid taxa representing 20 basic genomes in the Triticeae. Phylogenomic analysis and genetic divergence patterns suggested that (1) Kengyilia is closely related to Roegneria, Pseudoroegneria, Agropyron, Lophopyrum, Thinopyrum, and Dasypyrum; (2) both the StY genome Roegneria tetraploids and the PP genome Agropyron tetraploids served as the maternal donors during the speciation of Kengyilia species; (3) the different Kengyilia species derived their StY genome from different Roegneria species. Multiple origins of species via independent polyploidization events have occurred in the genus Kengyilia, resulting in a maternal haplotype polymorphism. This helps explain the rich diversity and wide adaptation of polyploid species in the genus Kengyilia.

Restriction fragment length polymorphism based phylogenetic analysis of Avena L.

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1279-1284 ◽  
Author(s):  
Rita Alicchio ◽  
Lina Aranci ◽  
Lucia Conte
Keyword(s):  
Fragment Length Polymorphism ◽  
Phylogenetic Analyses ◽  
Diploid Species ◽  
The Other ◽  
Molecular Approach ◽  
Polyploid Species ◽  
Species Relationships ◽  
Biochemical Traits ◽  
A Genome ◽  
Restriction Fragment Length

We report a molecular approach to the study of the phylogenetic relationships of Avena diploid and polyploid species based on RFLP detected with three cDNA probes of nuclear genes belonging to multigenic families (low pI α-amylase, avenin, and globulin). All the probes were highly informative in the detection of polymorphism between oat species. Associations between species were determined from cluster (UPGMA) analysis based on distance values calculated from RFLP data separately for each of the two levels of ploidy. Results were in general agreement with morphology based phylogenetic analyses, confirming the large differentiation among A and C genomes in the evolution of diploid species and the genetic homogeneity among A. brevis, A. strigosa, and A. nuda and the recently discovered A. atlantica. A certain divergence was observed between two endemic species (A. canariensis and A. damascena) and the other diploid species with the A genome. The analysis of tetraploid species relationships confirms the differentiation of the barbata complex (A. wiestii, A. barbata, A. abyssinica, and A. vaviloviana) from the maroccana–murphyi–agadiriana group, which, despite some similarities in morphological and biochemical traits, seems to have accumulated deep genetic differences along its evolutionary pathway.Key words: Avena genomes, genetic distance, ploidy, RFLP, multigenic families.

scholarly journals Chloroplast Phylogenomic Analyses Resolve Multiple Origins of the Kengyilia Species via Independent Polyploidization Events

2020 ◽  
Author(s):  
shiyong chen ◽  
Hao Yan ◽  
Li-Na Sha ◽  
Ning Chen ◽  
Xing Fan ◽  
...  
Keyword(s):  
Diploid Species ◽  
Sequence Divergence ◽  
Phylogenomic Analysis ◽  
Polyploid Species ◽  
Genome Doubling ◽  
Multiple Origins ◽  
Rich Diversity ◽  
Wide Adaptation ◽  
The Rich ◽  
Phylogenomic Analyses

Abstract Background Kengyilia is a group of allohexaploid species that arose from two hybridization events followed by genome doubling of three ancestral diploid species with different genomes St, Y and P in the wheat tribe. Estimating phylogenetic relationship in resolution of the maternal lineages has been difficult, owing to the extremely low rate of sequence divergence. Here, phylogenetic reconstructions based on the plastome sequences were used to explore the role of maternal progenitors in establishment of Kengyilia polyploid species.ResultsThe plastome sequences of 11 Kengyilia species were analyzed together with 11 tetraploid species (PP, StP, and StY) and 33 diploid taxa representing 20 basic genomes in the Triticeae. Phylogenomic analysis and genetic divergence patterns suggested that (1) Kengyilia is closely related to Roegneria, Pseudoroegneria, Agropyron, Lophopyrum, Thinopyrum, and Dasypyrum; (2) both the StY genome Roegneria tetraploids and the PP genome Agropyron tetraploids severed as the maternal donor during the speciation of Kengyilia species; (3) the different Kengyilia species derived their StY genome from different Roegneria species.ConclusionMultiple origins of species via independent polyploidization events have occurred in the genus Kengyilia, resulting in a maternal haplotype polymorphism. This helps explain the rich diversity and wide adaptation of polyploid species in the genus Kengyilia.

scholarly journals Chloroplast phylogenomic analyses resolve multiple origins of the Kengyilia species via independent polyploidization events

2020 ◽  
Author(s):  
Shi-Yong Chen ◽  
Hao Yan ◽  
Li-Na Sha ◽  
Ning Chen ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Diploid Species ◽  
Sequence Divergence ◽  
Phylogenomic Analysis ◽  
Polyploid Species ◽  
Genome Doubling ◽  
Multiple Origins ◽  
Rich Diversity ◽  
Wide Adaptation ◽  
The Rich ◽  
Phylogenomic Analyses

Abstract Background Kengyilia is a group of allohexaploid species that arose from two hybridization events followed by genome doubling of three ancestral diploid species with different genomes St, Y and P in the wheat tribe. Estimating phylogenetic relationship in resolution of the maternal lineages has been difficult, owing to the extremely low rate of sequence divergence. Here, phylogenetic reconstructions based on the plastome sequences were used to explore the role of maternal progenitors in establishment of Kengyilia polyploid species.ResultsThe plastome sequences of 11 Kengyilia species were analyzed together with 11 tetraploid species (PP, StP, and StY) and 33 diploid taxa representing 20 basic genomes in the Triticeae. Phylogenomic analysis and genetic divergence patterns suggested that (1) Kengyilia is closely related to Roegneria, Pseudoroegneria, Agropyron, Lophopyrum, Thinopyrum, and Dasypyrum; (2) both the StY genome Roegneria tetraploids and the PP genome Agropyron tetraploids severed as the maternal donor during the speciation of Kengyilia species; (3) the different Kengyilia species derived their StY genome from different Roegneria species.ConclusionMultiple origins of species via independent polyploidization events have occurred in the genus Kengyilia, resulting in a maternal haplotype polymorphism. This helps explain the rich diversity and wide adaptation of polyploid species in the genus Kengyilia.

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

scholarly journals Little hope for the polyploid endemic Pyrenean Larkspur (Delphinium montanum): evidences from population genomics and Ecological Niche Modelling

2021 ◽  
Author(s):  
Pascaline Salvado ◽  
Pere Aymerich Boixader ◽  
Josep Parera ◽  
Albert Vila Bonfill ◽  
Maria Martin ◽  
...  
Keyword(s):  
Population Structure ◽  
Ecological Niche ◽  
Population Genomics ◽  
Diploid Species ◽  
Ecological Niche Modelling ◽  
High Mountain ◽  
Suitable Habitat ◽  
Sky Islands ◽  
Niche Modelling ◽  
Ecological Requirements

Species endemic to restricted geographical ranges represent a particular conservation issue, be it for their heritage interest. In a context of global change, this is particularly the case for plants which belong to high-mountain ecosystems and, because of their ecological requirements, are doomed to survive or disappear on their "sky islands". The Pyrenean Larkspur (Delphinium montanum, Ranunculaceae) is endemic to the Eastern part of the Pyrenees (France and Spain). It is now only observable at a dozen of localities and some populations show signs of decline, such as a recurrent lack of flowering. Implementing population genomic approach (e.g. RAD-seq like) is particularly useful to understand genomic patterns of diversity and differentiation in order to provide recommendations in term of conservation. However, it remains challenging for species such as D. montanum that are autotetraploid with a large genome size (1C-value > 10 pg) as most methods currently available were developed for diploid species. A Bayesian framework able to call genotypes with uncertainty allowed us to assess genetic diversity and population structure in this system. Our results show evidence for inbreeding (mean GIS = 0.361) within all the populations and substantial population structure (mean GST = 0.403) at the metapopulation level. In addition to a lack of connectivity between populations, spatial projections of Ecological Niche Modelling analyses under different climatic scenarios predict a dramatic decrease of suitable habitat for D. montanum in the future. Based on these results, we discuss the relevance and feasibility of different conservation measures.

Evidence for genetic suppression of heterogenetic chromosome pairing in polyploidy species of Solanum, sect. Petota

1983 ◽  
Vol 25 (5) ◽  
pp. 530-539 ◽  
Author(s):  
Jan Dvořák
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Diploid Hybrid ◽  
Polyploid Species ◽  
Chromosome Differentiation ◽  
Genetic Suppression ◽  
Solanum Sect ◽  
Paradoxical Results

Data on chromosome pairing in haploids and interspecific hybrids of Solanum, sect. Petota reported in the literature were used to determine whether the diploidlike chromosome pairing that occurs in some of the polyploid species of the section is regulated by the genotype or brought about by some other mechanism. The following trends emerged from these data. Most of the polyploid × polyploid hybrids had high numbers of univalents, which seemed to indicate that the polyploid species were constructed from diverse genomes. Haploids, except for those derived from S. tuberosum, had incomplete chromosome pairing. All hybrids from diploid × diploid crosses had more or less regular chromosome pairing, which suggested that all investigated diploid species have the same genome. Likewise, hybrids from polyploid × diploid crosses had high levels of chromosome pairing. These paradoxical results are best explained if it is assumed that (i) the genotypes of most polyploid species, but not those of the diploid species, suppress heterogenetic pairing, (ii) that nonstructural chromosome differentiation is present among the genomes of both diploid and polyploid species, and (iii) the presence of the genome of a diploid species in a polyploid × diploid hybrid results in promotion of heterogenetic pairing. It is, therefore, concluded that heterogenetic pairing in most of the polyploid species is genetically suppressed.

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