J Syst Evol

• Research Articles •    

Phylogenetic relationships and the maternal donor of Roegneria (Triticeae: Poaceae) based on three nuclear DNA sequences (ITS, Acc1, and Pgk1) and one chloroplast region (trnL‐F)

Ying‐Xia Lei1 , Xing Fan2,3 , Li‐Na Sha2,3, Yi Wang2,3, Hou‐Yang Kang2,3, Yong‐Hong Zhou2,3, and Hai‐Qin Zhang2,3*   

  1. 1 Institute of Qinghai‐Tibetan Plateau, Southwest Minzu University, Chengdu 610041, China
    2 Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
    3 Key Laboratory of Crop Genetic Resources and Improvement Ministry of Education, Sichuan Agricultural University, Ya'an 625014, Sichuan, China
  • Received:2020-03-20 Accepted:2020-07-17 Online:2020-07-28

Abstract:

Roegneria is a polyploid perennial genus in the tribe Triticeae. Some species of Roegneria are morphologically similar to genus Elymus and have been classified in Elymus. To investigate the delimitation and phylogenetic relationships of Roegneria, nuclear (ITS, Acc1, and Pgk1) and chloroplast (trnL–trnF) DNA regions were sequenced for 38 allopolyploid species and 32 diploid species of Triticeae. Phylogenetic analyses of nuclear DNA revealed that all Roegneria species were included in the St and Y genome clades, and that the Y genome was closely related to the V and Xp genomes. The chloroplast DNA dataset showed that Roegneria species were grouped with Pseudoroegneria species. The Pseudoroegneria species from the Middle East (P. libanotica and P. tauri) and Central Asia (P. strigosa) were more closely related to Roegneria species. The results suggested that: (i) the species containing the St and Y genomes should be segregated from Elymus and treated as a distinct genus, Roegneria, based on the genomic constitution; (ii) P. libanotica, P. tauri, and/or P. strigosa potentially served as the maternal donor of the St genome in Roegneria; (iii) The Y genome of Roegneria originated from a diploid Y genome species, and the V and Xp genomes may have contributed to Y genome formation; (iv) among Roegneria species of previously uncertain genomic constitution, R. seriotina was tetraploid and possessed the StY genomes, E. calcicolus was hexaploid with the StYH genomic constitution and should be classified in Campeiostachys, R. glaucifolia possessed the StStY genomes, and R. tschimganica had the genomic constitution St1St2Y.

Key words: maternal donor, phylogenetic,  Roegneria,  Y genome