The Experts below are selected from a list of 7542 Experts worldwide ranked by ideXlab platform
Genlou Sun - One of the best experts on this subject based on the ideXlab platform.
-
Molecular phylogeny revealed complex evolutionary process in Elymus species
Journal of Systematics and Evolution, 2014Co-Authors: Genlou SunAbstract:Recent molecular phylogenetic studies on Elymus have added to our understanding of the origination of Elymus species. However, evolutionary dynamics and speciation of most species in Elymus are unclear. Molecular phylogeny has demonstrated that reticulate evolution has occurred extensively in the genus, as an example, the largest subunit of RNA polymerase II (rpb2) and phosphoenolpyruvate carboxylase (pepC) data revealed two versions of the St genome, St1 and St2 contributing to speciation of E. caninus. Phylogenetic analyses of E. pendulinus uncovered additional genome-level complexity. Our data indicated that both chloroplast and nuclear gene introgression have occurred in the evolutionary process of E. pendulinus. Non-donor species genomes have been detected in several Elymus species, such as in allohexaploid E. repens (StStStStHH), a Taeniatherum-like (Ta genome in Triticeae) GBSSI sequence, Bromus- (Bromeae) and Panicum-like (Paniceae) ITS sequences have been detected. The chloroplast DNA data indicated that Pseudoroegneria is the maternal genome donor to Elymus species, but whether different Elymus species originated from different St donors remains an open question. The origin of the Y genome in Elymus is puzzling. It is clear that the Y genome is distinct from the St genome, but unclear on the relationships of Y to other genomes in Triticeae. Introgressive hybridization may be an important factor complicating the evolutionary history of the species in Elymus. The extent of introgression and its role in creating diversity in Elymus species should be the objective of further investigations.
-
untangling nucleotide diversity and evolution of the h genome in polyploid hordeum and Elymus species based on the single copy of nuclear gene dmc1
PLOS ONE, 2012Co-Authors: Dongfa Sun, Genlou SunAbstract:Numerous hybrid and polypoid species are found within the Triticeae. It has been suggested that the H subgenome of allopolyploid Elymus (wheatgrass) species originated from diploid Hordeum (barley) species, but the role of hybridization between polyploid Elymus and Hordeum has not been studied. It is not clear whether gene flow across polyploid Hordeum and Elymus species has occurred following polyploid speciation. Answering these questions will provide new insights into the formation of these polyploid species, and the potential role of gene flow among polyploid species during polyploid evolution. In order to address these questions, disrupted meiotic cDNA1 (DMC1) data from the allopolyploid StH Elymus are analyzed together with diploid and polyploid Hordeum species. Phylogenetic analysis revealed that the H copies of DMC1 sequence in some Elymus are very close to the H copies of DMC1 sequence in some polyploid Hordeum species, indicating either that the H genome in theses Elymus and polyploid Hordeum species originated from same diploid donor or that gene flow has occurred among them. Our analysis also suggested that the H genomes in Elymus species originated from limited gene pool, while H genomes in Hordeum polyploids have originated from broad gene pools. Nucleotide diversity (π) of the DMC1 sequences on H genome from polyploid species (π = 0.02083 in Elymus, π = 0.01680 in polyploid Hordeum) is higher than that in diploid Hordeum (π = 0.01488). The estimates of Tajima's D were significantly departure from the equilibrium neutral model at this locus in diploid Hordeum species (P<0.05), suggesting an excess of rare variants in diploid species which may not contribute to the origination of polyploids. Nucleotide diversity (π) of the DMC1 sequences in Elymus polyploid species (π = 0.02083) is higher than that in polyploid Hordeum (π = 0.01680), suggesting that the degree of relationships between two parents of a polyploid might be a factor affecting nucleotide diversity in allopolyploids.
-
Origin of the H genome in StH-genomic Elymus species based on the single-copy nuclear gene DMC1.
Genome, 2011Co-Authors: Genlou Sun, Xiaodi ZhangAbstract:Previous studies have suggested that the H haplome in Elymus could originate from different diploid Hordeum species, however, which diploid species best represent the parental species remains unanswered. The focus of this study seeks to pinpoint the origin of the H genome in Elymus. Allopolyploid Elymus species that contain the StH genome were analyzed together with diploid Hordeum species and a broad sample of diploid genera in the tribe Triticeae using DMC1 sequences. Both parsimony and maximum likelihood analyses well separated the American Hordeum species, except Hordeum brachyantherum subsp. californicum, from the H genome of polyploid Elymus species. The Elymus H-genomic sequences were formed into different groups. Our data suggested that the American Horedeum species, except H. brachyantherum subsp. californicum, are not the H-genomic donor to the Elymus species. Hordeum brevisubulatum subsp. violaceum was the progenitor species to Elymus virescens, Elymus confusus, Elymus lanceolatus, Elymus wawaw...
-
Nucleotide diversity and minisatellite in chloroplast Asp(GUC)–Thr(GGU) region in Elymus trachycaulus complex, Elymus alaskanus and Elymus caninus
Biochemical Systematics and Ecology, 2009Co-Authors: Genlou SunAbstract:Abstract Nucleotide variation in chloroplast Asp(GUC)–Thr(GGU) intergenic region and genetic relationships among this group were examined among Elymus trachycaulus complex, Elymus alaskanus and Elymus caninus . The estimates of nucleotide diversity ( π ) ranged from 0.00111 for Elymus virescens to 0.03086 for E. caninus . Highest nucleotide diversity was found for E. caninus among the taxa analyzed here and followed by Elymus hyperarcticus . E. virescens accessions are genetically very uniform. Phylogenetic analysis suggested that E. caninus is paraphyletic. Elymus violaceus is genetically distinct from both E. alaskanus and E. trachycaulus . Our result indicates that Asp (GUC)–Thr (GGU) intergenic region has a high rate of evolutionary in Elymus species. Large indels detected in this region appear to have a highly rate of evolution and are thus more prone to homoplasy. We also first reported a minisatellite discovered in Asp (GUC)–Thr (GGU) region in Elymus species. The minisatellite identified here is an excellent candidate marker for studying population structures of Elymus species.
-
Molecular evolution and origin of tetraploid Elymus species
Breeding Science, 2009Co-Authors: Genlou Sun, Björn SalomonAbstract:It is well known that Elymus arose through hybridization between representatives of different genera and several different polyhaplomic genomes have been described. Cytogenetically, five basic genomes (St, H, Y, P and W) in different combinations have been found in the genus. The vast majority of species are tetraploids and they are characterized by having the StY genome or the StH genome. It is not known where the Y genome originated, although it is a common in Elymus from Central and East Asia. It has been hypothesized from isozymic and cytological studies of Elymus species that the Old and New World taxa may be of separate origin of the H genome in the StH genome species. Data from single copy of nuclear gene RPB2 indicated that the Eurasian and American StH genome species have independent alloploid origins with different Hgenome donors. This hypothesis is needed to be tested by using more molecular data. Sequences from single copy of nuclear genes (RPB2, β-amylase gene and EF-G) indicated that StY genome species is allopolyploid origin. This paper presents a briefly review on current status of molecular evolution and origin of tetraploid Elymus species.
Xing Fan - One of the best experts on this subject based on the ideXlab platform.
-
genomic constitution and taxonomy of the chinese hexaploids Elymus cylindricus and e breviaristatus poaceae triticeae
Botanical Journal of the Linnean Society, 2016Co-Authors: Cairong Yang, Bernard R. Baum, Xing Fan, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Weihuan Chen, Xiaoyan Liu, Yonghong ZhouAbstract:Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north-western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth (StH), Roegneria grandis Keng (StY) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L.Yang & C.Yen var. dahurica (StYH). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis (StH), E. cylindricus × R. grandis (StY) and E. cylindricus × C. dahurica var. dahurica (StYH) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica (StYH) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GISH) revealed the presence of St, Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GISH. Meiotic pairing data and GISH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively.
-
phylogeny and differentiation of the st genome in Elymus l sensu lato triticeae poaceae based on one nuclear dna and two chloroplast genes
BMC Plant Biology, 2015Co-Authors: Zhen-zhen Dong, Li Zhang, Xing Fan, Lina Sha, Jian Zeng, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Chunbang DingAbstract:Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria, Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes (matK and the intergenic region of trnH-psbA) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria. The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum, and E. breviaristatus should be transferred into Campeiostachys. We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.
-
phylogenetic relationships and y genome origin in Elymus l sensu lato triticeae poaceae based on single copy nuclear acc1 and pgk1 gene sequences
Molecular Phylogenetics and Evolution, 2013Co-Authors: Xing Fan, Chunbang Ding, Li Zhang, Zhen-zhen Dong, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Ruiwu YangAbstract:To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
-
Phylogeny and molecular evolution of the rbcL gene of St genome in Elymus sensu lato (Poaceae: Triticeae)
Biochemical Systematics and Ecology, 2013Co-Authors: Zhen-zhen Dong, Xing Fan, Lina Sha, Jian Zeng, Yi Wang, Qian Chen, Houyang Kang, Hai-qin Zhang, Yonghong ZhouAbstract:Abstract Analysis of the patterns and levels of diversity in duplicate gene not only traces evolutionary history of polyploids, but also provides insight into how the evolutionary process differs between lineages and between homoeologous loci within lineages. Elymus sensu lato is a group of allopolyploid species, which share a common St genome and with the different combinations of H, Y, P, and W genomes. To estimate the evolutionary process of the rbc L gene in species of Elymus s. l. and its putative dioploid relatives, 74 sequences were obtained from 21 species of Elymus s. l. together with 24 diploid taxa representing 19 basic genomes in Triticeae. Phylogeny and sequence diversity pattern analysis suggested that (1) species of Pseudoroegneria (Nevski) A. Love might serve as the maternal donor of the species of Elymus s. l; (2) differentiation of St genome were shown in the species of Elymus s. l. following polyploidy event; (3) divergences within the species might associate with geographic diversity and morphological variability; (4) differences in the levels and patterns of nucleotide diversity of the rbc L gene implied that the St genome lineages in the species of Elymus s. l. have differently evolutionary potentials.
Chunbang Ding - One of the best experts on this subject based on the ideXlab platform.
-
phylogeny and differentiation of the st genome in Elymus l sensu lato triticeae poaceae based on one nuclear dna and two chloroplast genes
BMC Plant Biology, 2015Co-Authors: Zhen-zhen Dong, Li Zhang, Xing Fan, Lina Sha, Jian Zeng, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Chunbang DingAbstract:Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria, Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes (matK and the intergenic region of trnH-psbA) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria. The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum, and E. breviaristatus should be transferred into Campeiostachys. We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.
-
Phylogenetic relationships among Elymus and related diploid genera (Triticeae: Poaceae) based on nuclear rDNA ITS sequences
Biologia, 2015Co-Authors: Gang Gao, Yonghong Zhou, Xuemei Gou, Qian Wang, Jiabin Deng, Chunbang Ding, Li Zhang, Ruiwu YangAbstract:To investigate the phylogenetic relationships among Elymus and related diploid genera, the genome donor of Elymus, and the evolutionary history of polyploid Elymus species, nuclear ribosomal internal transcribed spacer (ITS) sequences were analyzed for 10 Elymus species, together with 17 diploid taxa from 5 monogenomic genera. The phylogenetic analyses (Neighbor-Joining) supported two major clades (St and H). Sequence diversity and genealogical analysis suggested that (1) Elymus species were unambiguously closely related to Pseudoroegeria; (2) Pse. stipifolia might be serve as the St genome donor of polyploid Elymus species; (3) the Y genome might be originated from ancestral lineage of Pseudoroegneria (St); (4) the ITS sequences of Elymus were evolutionarily distinct and may clarify parental lineages and phylogenetic relationships in Elymus.
-
Phylogenetic relationships and Y genome origin in Chinese Elymus (Triticeae: Poaceae) based on single copy gene DMC1
Biochemical Systematics and Ecology, 2014Co-Authors: Gang Gao, Yonghong Zhou, Xuemei Gou, Qian Wang, Yan Zhang, Jiabin Deng, Chunbang Ding, Li Zhang, Ruiwu YangAbstract:Abstract To investigate the phylogenetic relationships among Chinese Elymus and related diploid genera, the genome donor of Elymus, and the evolutionary history of polyploid Elymus species, disrupted meiotic cDNA1 (DMC1) sequences were analyzed for 10 Elymus species, together with 34 diploid taxa from 13 monogenomic genera. The phylogenetic analyses (Neighbor-Joining) supported three major clades (St, Y and H). Sequence diversity and genealogical analysis suggested that (1) Elymus species are unambiguously closely related to Pseudoroegeria and Hordeum. Pseudoroegeria and Hordeum might be serve as the St genome and H genome donor of polyploid Elymus species; (2) Phylogenetic analyses separated the Y sequences from the St sequences, it confirmed that St and Y genome in Elymus species have originated from different donors; (3) the St genome of Elymus had several origins and diverse species of Pseudoroegneria might have taken part in the formation of polyploid species of Elymus; (4) the DMC1 sequences of Elymus are evolutionarily distinct, and it can clarify parental lineages and phylogenetic relationships of genera Elymus.
-
phylogenetic relationships and y genome origin in Elymus l sensu lato triticeae poaceae based on single copy nuclear acc1 and pgk1 gene sequences
Molecular Phylogenetics and Evolution, 2013Co-Authors: Xing Fan, Chunbang Ding, Li Zhang, Zhen-zhen Dong, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Ruiwu YangAbstract:To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
-
PCR-RFLP analysis on Roegneria, Elymus, Hystrix and Kengyilia in Triticeae (Poaceae)
Yi chuan = Hereditas, 2006Co-Authors: Ying Zhang, Ruiwu Yang, Yonghong Zhou, Li Zhang, Hai-qin Zhang, Chunbang DingAbstract:PCR-RFLP of Plasmon on 23 species of Roegneria, Elymus, Hystrix and Kengyilia and 1 outgroup (Triticum aestivum L.) was carried out. The segments amplified with 3 cpDNA and 3 mtDNA universal primers were digested by 15 restriction endonucleases. Among 329 bands produced, 304 were polymorphic (92.4%). PCR-RFLP results showed that polymorphisms existed between the four genera and between the species in Roegneria, Elymus, Hystrix and Kengyilia, and genetic similarity coefficient was high. Roegneria grandis, R. aristiglumis, R. elytrigioides, R. alashanica and R. magnicaespes were grouped, while R. caucasica, R. ciliaris, R. amurensis and R. japonensis clustered together. Species of Kengyilia clustered independently. Five species of Elymus, 3 of Hystrix and Roegneria kamoji grouped together. The results suggested Kengyilia was a valid genus. As more cytological and molecular data are available, the taxonomic status of Roegneria, Elymus and Hystrix will be recognized.
Ruiwu Yang - One of the best experts on this subject based on the ideXlab platform.
-
Phylogeny and maternal donor of Elymus (Triticeae: Poaceae) in China based on chloroplast mat K sequences
Biologia, 2017Co-Authors: Gang Gao, Yonghong Zhou, Yan Zhang, Jiabin Deng, Shan-shan Tong, Chao Zhang, Ruiwu YangAbstract:Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The chloroplast DNA regionsmatK was used to analyze to phylogenetic relationships and maternal donor of Elymus species and their closely related species. The Neighbor-Joining phylogenetic reconstructions partitioned the species into one monophyletic groups. All the Elymus species were related to species of Pseudoroegneria. These results indicated that Pseudoroegneria (St genome) was the maternal donor of the polyploidy Elymus. In addition, the St genome of Elymus had several origins and diverse species of Pseudoroegneria might have taken part in the formation of polyploid species of Elymus.
-
Phylogeny and maternal donor of Chinese Elymus (Triticeae: Poaceae) inferred from chloroplast trnH-psbA sequences
Biochemical Systematics and Ecology, 2016Co-Authors: Gang Gao, Yonghong Zhou, Yan Zhang, Jiabin Deng, Ruiwu YangAbstract:Abstract Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The chloroplast DNA regions trnH-psbA was used to analyze to phylogenetic relationships and maternal donor of Elymus species and their closely related species. The Neighbor-Joining phylogenetic reconstructions partitioned the Elymus species into two groups. All the Elymus species were related to species of Pseudoroegneria. These results indicated that (1) Pseudoroegneria (St genome) was the maternal donor of the polyploidy Elymus; (2) the St genome of Elymus had several origins and diverse species of Pseudoroegneria might have taken part in the formation of polyploid species of Elymus; (3) high degree genome differentiation exists among the Pseudoroegneria species.
-
Phylogenetic relationships among Elymus and related diploid genera (Triticeae: Poaceae) based on nuclear rDNA ITS sequences
Biologia, 2015Co-Authors: Gang Gao, Yonghong Zhou, Xuemei Gou, Qian Wang, Jiabin Deng, Chunbang Ding, Li Zhang, Ruiwu YangAbstract:To investigate the phylogenetic relationships among Elymus and related diploid genera, the genome donor of Elymus, and the evolutionary history of polyploid Elymus species, nuclear ribosomal internal transcribed spacer (ITS) sequences were analyzed for 10 Elymus species, together with 17 diploid taxa from 5 monogenomic genera. The phylogenetic analyses (Neighbor-Joining) supported two major clades (St and H). Sequence diversity and genealogical analysis suggested that (1) Elymus species were unambiguously closely related to Pseudoroegeria; (2) Pse. stipifolia might be serve as the St genome donor of polyploid Elymus species; (3) the Y genome might be originated from ancestral lineage of Pseudoroegneria (St); (4) the ITS sequences of Elymus were evolutionarily distinct and may clarify parental lineages and phylogenetic relationships in Elymus.
-
Phylogenetic relationships and Y genome origin in Chinese Elymus (Triticeae: Poaceae) based on single copy gene DMC1
Biochemical Systematics and Ecology, 2014Co-Authors: Gang Gao, Yonghong Zhou, Xuemei Gou, Qian Wang, Yan Zhang, Jiabin Deng, Chunbang Ding, Li Zhang, Ruiwu YangAbstract:Abstract To investigate the phylogenetic relationships among Chinese Elymus and related diploid genera, the genome donor of Elymus, and the evolutionary history of polyploid Elymus species, disrupted meiotic cDNA1 (DMC1) sequences were analyzed for 10 Elymus species, together with 34 diploid taxa from 13 monogenomic genera. The phylogenetic analyses (Neighbor-Joining) supported three major clades (St, Y and H). Sequence diversity and genealogical analysis suggested that (1) Elymus species are unambiguously closely related to Pseudoroegeria and Hordeum. Pseudoroegeria and Hordeum might be serve as the St genome and H genome donor of polyploid Elymus species; (2) Phylogenetic analyses separated the Y sequences from the St sequences, it confirmed that St and Y genome in Elymus species have originated from different donors; (3) the St genome of Elymus had several origins and diverse species of Pseudoroegneria might have taken part in the formation of polyploid species of Elymus; (4) the DMC1 sequences of Elymus are evolutionarily distinct, and it can clarify parental lineages and phylogenetic relationships of genera Elymus.
-
phylogenetic relationships and y genome origin in Elymus l sensu lato triticeae poaceae based on single copy nuclear acc1 and pgk1 gene sequences
Molecular Phylogenetics and Evolution, 2013Co-Authors: Xing Fan, Chunbang Ding, Li Zhang, Zhen-zhen Dong, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Ruiwu YangAbstract:To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
Hai-qin Zhang - One of the best experts on this subject based on the ideXlab platform.
-
genomic constitution and taxonomy of the chinese hexaploids Elymus cylindricus and e breviaristatus poaceae triticeae
Botanical Journal of the Linnean Society, 2016Co-Authors: Cairong Yang, Bernard R. Baum, Xing Fan, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Weihuan Chen, Xiaoyan Liu, Yonghong ZhouAbstract:Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north-western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth (StH), Roegneria grandis Keng (StY) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L.Yang & C.Yen var. dahurica (StYH). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis (StH), E. cylindricus × R. grandis (StY) and E. cylindricus × C. dahurica var. dahurica (StYH) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica (StYH) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GISH) revealed the presence of St, Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GISH. Meiotic pairing data and GISH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively.
-
phylogeny and differentiation of the st genome in Elymus l sensu lato triticeae poaceae based on one nuclear dna and two chloroplast genes
BMC Plant Biology, 2015Co-Authors: Zhen-zhen Dong, Li Zhang, Xing Fan, Lina Sha, Jian Zeng, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Chunbang DingAbstract:Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria, Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes (matK and the intergenic region of trnH-psbA) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria. The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum, and E. breviaristatus should be transferred into Campeiostachys. We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.
-
phylogenetic relationships and y genome origin in Elymus l sensu lato triticeae poaceae based on single copy nuclear acc1 and pgk1 gene sequences
Molecular Phylogenetics and Evolution, 2013Co-Authors: Xing Fan, Chunbang Ding, Li Zhang, Zhen-zhen Dong, Lina Sha, Yi Wang, Houyang Kang, Hai-qin Zhang, Xiaoli Wang, Ruiwu YangAbstract:To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
-
Phylogeny and molecular evolution of the rbcL gene of St genome in Elymus sensu lato (Poaceae: Triticeae)
Biochemical Systematics and Ecology, 2013Co-Authors: Zhen-zhen Dong, Xing Fan, Lina Sha, Jian Zeng, Yi Wang, Qian Chen, Houyang Kang, Hai-qin Zhang, Yonghong ZhouAbstract:Abstract Analysis of the patterns and levels of diversity in duplicate gene not only traces evolutionary history of polyploids, but also provides insight into how the evolutionary process differs between lineages and between homoeologous loci within lineages. Elymus sensu lato is a group of allopolyploid species, which share a common St genome and with the different combinations of H, Y, P, and W genomes. To estimate the evolutionary process of the rbc L gene in species of Elymus s. l. and its putative dioploid relatives, 74 sequences were obtained from 21 species of Elymus s. l. together with 24 diploid taxa representing 19 basic genomes in Triticeae. Phylogeny and sequence diversity pattern analysis suggested that (1) species of Pseudoroegneria (Nevski) A. Love might serve as the maternal donor of the species of Elymus s. l; (2) differentiation of St genome were shown in the species of Elymus s. l. following polyploidy event; (3) divergences within the species might associate with geographic diversity and morphological variability; (4) differences in the levels and patterns of nucleotide diversity of the rbc L gene implied that the St genome lineages in the species of Elymus s. l. have differently evolutionary potentials.
-
PCR-RFLP analysis on Roegneria, Elymus, Hystrix and Kengyilia in Triticeae (Poaceae)
Yi chuan = Hereditas, 2006Co-Authors: Ying Zhang, Ruiwu Yang, Yonghong Zhou, Li Zhang, Hai-qin Zhang, Chunbang DingAbstract:PCR-RFLP of Plasmon on 23 species of Roegneria, Elymus, Hystrix and Kengyilia and 1 outgroup (Triticum aestivum L.) was carried out. The segments amplified with 3 cpDNA and 3 mtDNA universal primers were digested by 15 restriction endonucleases. Among 329 bands produced, 304 were polymorphic (92.4%). PCR-RFLP results showed that polymorphisms existed between the four genera and between the species in Roegneria, Elymus, Hystrix and Kengyilia, and genetic similarity coefficient was high. Roegneria grandis, R. aristiglumis, R. elytrigioides, R. alashanica and R. magnicaespes were grouped, while R. caucasica, R. ciliaris, R. amurensis and R. japonensis clustered together. Species of Kengyilia clustered independently. Five species of Elymus, 3 of Hystrix and Roegneria kamoji grouped together. The results suggested Kengyilia was a valid genus. As more cytological and molecular data are available, the taxonomic status of Roegneria, Elymus and Hystrix will be recognized.