Abstract:

The study was conducted to evaluate the genetic similarity between the major commercial and the landraces rice varieties in Yunnan and the rice varieties from different geographic regions. The genetic similarity and cluster of 90 accessions of tested rice variety from 9 countries were analyzed using 48 SSR markers. The results showed that totally 269 numbers of allele (Na) were detected among these tested rice varieties with the average number of alleles per pair of primers was 5.604, with a range from 3 to 10. Totally 159.775 effective number of alleles (Ne) were detected with the average number of effects per pair of primers was 3.329, with a range from 1.578 to 6.090. The average value of locus polymorphism information content (PIC) was 0.661, with a range from 0.366 to 0.836. The range of genetic similar index among tested rice varieties from different countries was from 0.021 to 0.875, with the average of 0.328. Cluster analysis results showed that 90 tested varieties could be distinguished as indica and japonica at the similarity coefficient level of 0.212. Cluster analysis could be classified better into groups according to geographical regions also. The genetic similarity of japonica was higher than that of indica among the subspecies. On the basis of the above data, the genetic diversity of the landraces was higher, but the genetic similarity was higher among the improved japonica rice varieties from Yunnan province. It is suggested that more attention should be paid to both conservation of rice landraces as well as to the study of differentiation between Oryza sativa indica and japonica subspecies in Yunnan province.