Identification and formation of natural hybrids of Campeiostachys in Triticeae

In this study, morphological, cytological, and phylogenetic analyses were used to identify two suspected natural hybrids in the genus Campeiostachys. Results showed that the two natural hybrids were similar to C.breviaristata (Keng) Y. H. Zhou, H. Q. Zhang et C. R. Yang. morphologically, but had low pollen fertility (13.30% and 21.20%) and seed setting (10.70% and 18.60%). Cytological studies showed that the two hybrids were hexaploids (2n=42), with StStYYHH genomes. Phylogenetic analysis based on the nuclear gene DMC1 and chloroplast gene rps16 showed that the possible parents of the natural hybrids were C. breviaristata,Elymus submuticus Keng, and Elymus atratus (Nevski) Hand.-Mazz, with C. breviaristata being the female parent. Considering the hybrids had no or short awns, we inferred that C. breviaristata (female parent) and E. submuticus may be the parental species of these two natural hybrids.