籼-粳稻特异插入／缺失分子标记揭示的稻属植物遗传分化

Indica-japonica differentiation is the most significant genetic variation among varietal types of Asian cultivated rice (Oryza sativa L.). Despite its important roles in the domestication process of Asian cultivated rice, the mechanisms of indica-japonica differentiation are still unclear. One of the hypotheses stresses that the differentiation of indica-japonica has occurred in the wild ancestral species. In order to investigate the indica-japonica genetic variation in all wild relatives in the genus Oryza, 50 typical indica and japonica rice cultivars and 348 wild Oryza accessions from 35 countries were included in the study using 34 indica-japonica specified InDel primer pairs. The results indicated that significant indica-japonica differentiation occurred in Asian cultivated rice, and some ”indica” and ”japonica” types were also found in some of the O. rufipogon complex. However, no such differentiation were detected in other Oryza species. The geographical distribution pattern of ”indica” and ”japonica” types in the O. rufipogon complex is associated with the geographical distribution of indica and japonica rice varieties. Given the wild accessions were collected in habitats adjacent to the fields of cultivated rice, we believe that the ”indica” and ”japonica” types in O. rufipogon complex is more likely generated by the introgression from the respective ”indica” or ”japonica” rice varieties historically.