Biosystematics and Taxonomic Treatment of Three New Kengyilia Species in the Triticeae (Poaceae)

In the present study, we discovered and investigated three new species of Kengyilia (Triticeae, Poaceae): Kengyilia changduensis C. B. Zhang, H. Q. Zhang et Y. H. Zhou, Kengyilia dingqinensis Y. H. Zhou, D. D. Wu et X. Y. Pan, and Kengyilia tibetica Y. H. Zhou, C. B. Zhang et D. D. Wu, in Changdu, Tibet, China based on morphological, cytological, and molecular data. Each species is morphologically characterized and distinguished from existing Kengyilia species by smooth internodes, glumes oblong- lanceolate and awns 2 mm, lemmas pubescent and awns 5–10 mm of K. changduensis, the lower part of the spikes is sparse, internodes hairy, glumes covered with soft hairs, awns 2 mm, lemmas oblong and awns 5 mm of K. dingqinensis, and internodes hairy, glumes oblong-lanceolate and awns 2–6 mm of K. tibetica. The genomic in situ hybridization results confirm that K. changduensis, K. dingqinensis, and K. tibetica are allohexaploid with StStYYPP genomic constitutions. Phylogenetic analyses, based on GBSSI nuclear gene and chloroplast genome sequences, suggest that K. changduensis, K. dingqinensis, and K. tibetica were closely related to genera Pseudoroegneria, Roegneria and Agropyron, and the Roegneria served as the maternal donors during its polyploid speciation of K. changduensis and K. tibetica, and Agropyron served as the maternal donors of K. dingqinensis.