Abstract:

【Objective】 The genetic similarity and genetic difference among improved japonica rice varieties from different provinces of China were analyzed. The aim is to provide genetic basis for the breeding of japonica rice varieties. 【Method】 The genetic similarity and cluster of 139 accessions of improved japonica rice variety from 12 provinces of China were analyzed using 34 SSR markers. 【Result】 Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286 and RM336 showed more alleles, which were 15, 12, 11, 9 and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes, which were 2.3324, 2.0292, 1.8996 and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There is a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there is a low genetic similarity between improved japonica rice germplasm from Guizhou and Jiangsu, and those of other provinces, which located in more different latitudes and ecological environments. 【Conclusion】 The marker of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.

Key words: improved japonica rice variety, genetic similarity, genetic basis of parent, ecological and climatic environment, SSR marker