Phylogeny and molecular evolution of the DNIC1 gene in the polyploid genus Leymus （Triticeae： Poaceae） and its diploid relatives  

作　　者：Li-Na Sha Xing Fan Hai-Qin Zhang Hou-Yang Kang Yi Wang Xiao-Li Wang Xiao-Fang Yu Yong-Hong Zhou 

机构地区：[1]Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China [2]Key Laboratory of Crop Genetic Resources and Improvement, Ministry of Education, Sichuan Agricultural University, Yaan 625014,Sichuan, China [3]College of Life Science, Sichuan Agricultural University, Yaan 625014, Sichuan, China [4]College of Landscape Architecture, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China

出　　处：《Journal of Systematics and Evolution》2016年第3期250-263,共14页植物分类学报（英文版）

基　　金：Acknowledgements This study was funded by the National Natural Science Foundation of China （Grant Nos. 30900087, 31200252, 31270243, and 31470305）, the Special Fund for Agro-Scientific Research in the Public Interest of China （Grant No. 201003021）, and the Science and Technology Bureau （Grant No. 2060503） and Education Bureau of Sichuan Province. We are very grateful to the American National Plant Germplasm System （Pullman, WA, USA） for providing many seed materials for this study.

摘　　要：The level and pattern of nucleotide variation in duplicate genes provide important information on the evolutionary history of polyploids and divergent processes between homoeologous loci within lineages. Leymus, a group of allopolyploid species with the NsXm genomes, is a perennial genus with a diverse array of morphology, ecology, and distribution in Triticeae. To estimate the phylogeny and molecular evolution of a single-copy DIVIC1 gene in Leymus and its diploid relatives, DMO homoeologous sequences were isolated from the sampled Leymus species and were analyzed with those from 30 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that： （i） different Leymus species might derive their Ns genome from different Psatbyrostachys species; （ii） Pseudoroegneria has contributed to the nuclear genome of some Leymus species, which might result from recurrent hybridization or incomplete lineage sorting; （iii） the Xm genome origin of Leymus could differ among species; （iv） rapid radiation and multiple origin might account for the rich diversity, numbers of species, and wide ecological adaptation of Leymus species; and （v） the DA/IC1 sequence diversity of the Ns genome in Leymus species was lower than that in the Psathyrostachys diploids, while the level of DMC1 sequence diversity in Leymus was higher than that in diploid Pseudoroegneria. Our results provide new insight on the evolutionary dynamics of duplicate DMC1 genes, polyploid speciation, and the phylogeny of Leymus species.The level and pattern of nucleotide variation in duplicate genes provide important information on the evolutionary history of polyploids and divergent processes between homoeologous loci within lineages. Leymus, a group of allopolyploid species with the NsXm genomes, is a perennial genus with a diverse array of morphology, ecology, and distribution in Triticeae. To estimate the phylogeny and molecular evolution of a single-copy DIVIC1 gene in Leymus and its diploid relatives, DMO homoeologous sequences were isolated from the sampled Leymus species and were analyzed with those from 30 diploid taxa representing 18 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that： （i） different Leymus species might derive their Ns genome from different Psatbyrostachys species; （ii） Pseudoroegneria has contributed to the nuclear genome of some Leymus species, which might result from recurrent hybridization or incomplete lineage sorting; （iii） the Xm genome origin of Leymus could differ among species; （iv） rapid radiation and multiple origin might account for the rich diversity, numbers of species, and wide ecological adaptation of Leymus species; and （v） the DA/IC1 sequence diversity of the Ns genome in Leymus species was lower than that in the Psathyrostachys diploids, while the level of DMC1 sequence diversity in Leymus was higher than that in diploid Pseudoroegneria. Our results provide new insight on the evolutionary dynamics of duplicate DMC1 genes, polyploid speciation, and the phylogeny of Leymus species.

关 键 词：DMC1 evolutionary pattern LEYMUS PHYLOGENY polyploidy. 

分 类 号：S888.31[农业科学—特种经济动物饲养] S681.5[农业科学—畜牧兽医]