Genomic constitution of {\sl Roegneria glaberrima}

Intergeneric and interspecific hybridization of Roegneria glaberrima (tetraploid: 2n=4x=28) with three analyzer species, i.e., Pseudoroegneria spicata (diploid: 2n=2x=14, St), Roegneria dolichathera (tetraploid: 2n=4x=28, StY) and Roegneria kamoji (hexaploid: 2n=6x=42, StYH), were performed successfully. Chromosome pairing at metaphase-I in meiosis of pollen mother cells was studied in the parental species and hybrids to determine the genomic constitution of R. glaberrima. It is concluded from this study that R. glaberrima i) behaves in a strict allotetraploid nature, comprised of two different genomes; ii) contains the St and Y genomes; iii) is closely related to R. dolichathera; and i) is a valid species of Roegneria, which comprises taxa with StY and StYH genomes.