Molecular cytogenetic characterization of natural hybrids of Roegneria
stricta and Roegneria turczaninovii (Triticeae: Poaceae)
Abstract
Hybridization is an important part of species evolution. The hybrid
progeny population had rich genetic and phenotypic variation, which made
the boundaries between them and their parents blurred and difficult to
distinguish. There was little research on the origin of natural hybrids
of Triticeae. In this study, we found a large number of putative hybrids
of Roegneria in West Sichuan Plateau, China. The hybrid plants showed
strong heterosis in plant height, tiller number and floret number.
Morphologically, the putative hybrids showed intermediate of Roegneria
stricta Keng and Roegneria turczaninovii (Drob.) Nevski. Hybrids had 28
chromosomes corresponding to that of R. stricta and R. turczaninovii
(2n=4x=28). Meiotic pairing in hybrids were less regular than those of
R. stricta and R. turczaninovii. GISH analysis showed that the hybrid
plants had the same genome as that of R. stricta and R. turczaninovii
(StY). Phylogenetic analysis based on the single copy nuclear gene DMC1
and chloroplast gene rps16 showed the plants were closely related to R.
stricta and R. turczaninovii. This study indicated that the plants were
hybrids of R. stricta and R. turczaninovii. The results provided data
for the utilization of hybrid. This study provided a case study of
natural hybrids.