Origin and Evolution of Allopolyploid Wheatgrass Elymus fibrosus (Schrenk) Tzvelev (Poaceae: Triticeae) Reveals the Effect of Its Origination on Genetic Diversity.

De-Chuan Wu,Wei-Jie Wang,Deng-Min He,Han-Feng Shi,De-Xiang Wu,Genlou Sun,Hai-Lan Gu,Pan-Pan Wu,Xu Yi

doi:10.1371/journal.pone.0167795

De-Chuan Wu, Wei-Jie Wang + Show 7 more

Open Access

https://doi.org/10.1371/journal.pone.0167795

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Journal: PloS one	Publication Date: Dec 9, 2016
Citations: 5	License type: CC BY 4.0

Affiliation: Anhui Agricultural University, Saint Mary's University

Abstract

Origin and evolution of tetraploid Elymus fibrosus (Schrenk) Tzvelev were characterized using low-copy nuclear gene Rpb2 (the second largest subunit of RNA polymerase II), and chloroplast region trnL–trnF (spacer between the tRNA Leu (UAA) gene and the tRNA-Phe (GAA) gene). Ten accessions of E. fibrosus along with 19 Elymus species with StH genomic constitution and diploid species in the tribe Triticeae were analyzed. Chloroplast trnL–trnF sequence data suggested that Pseudoroegneria (St genome) was the maternal donor of E. fibrosus. Rpb2 data confirmed the presence of StH genomes in E. fibrosus, and suggested that St and H genomes in E. fibrosus each is more likely originated from single gene pool. Single origin of E. fibrosus might be one of the reasons causing genetic diversity in E. fibrosus lower than those in E. caninus and E. trachycaulus, which have similar ecological preferences and breeding systems with E. fibrosus, and each was originated from multiple sources. Convergent evolution of St and H copy Rpb2 sequences in some accessions of E. fibrosus might have occurred during the evolutionary history of this allotetraploid.

Highlights

The tribe Triticeae includes the world’s most economically important cereal crops and forage grasses, and troublesome weeds distributed all over the world
Elymus fibrosus was considered as a tetraploid containing the genomes of a Pseudoroegneria species (St genome) and a wild Hordeum species (H genome) [1]
The phylogenetic analysis based on TrnL-F data here grouped all sequences from E. fibrosus with the sequences from diploid Pseudoroegneria species (St genome), Dasypyrum villosum (V), other Elymus species and Thinopyrum intermedium together (Fig 2)

Summary

Introduction

The tribe Triticeae includes the world’s most economically important cereal crops and forage grasses, and troublesome weeds distributed all over the world Within this tribe, three quarters of the species are polyploids [1]. Is one of StH genome species with a predominantly selfpollinating, distributed in Russia and northern Scandinavia [14]. It grows on wet meadows, riverside sand and pebbles, and among shrubs. Elymus fibrosus is a tetraploid containing genomes of a Pseudoroegneria species (St genome) and a wild Hordeum species (H genome) [1], but its origin was rarely explored at molecular level. The effect of origination on genetic diversity of this species was discussed

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