DNA fingerprints construction and genetic similarity analysis of conventional japonica rice from Taihu Lake area based on SSR markers.

[Objective] The present experiment was conducted to construct DNA fingerprint map of japonica rice varieties (Oryza sativa L. Subsp. Japonica % collected from Taihu Lake area, and analyze their genetic similarity in order to provide reference for japonica rice variety breeding and identification of seed purity. [Method] By taking 19 conventional japonica rice varieties with high quality from Taihu Lake rice area as materials, their DNA fingerprint maps were constructed by using 24 pairs of SSR primers distributed in 12 chromosomes of rice, and genetic similarity were also analyzed to conduct clustering analysis. [Result] By using 24 pairs of SSR primers, 99 alleles were detected out from 19 japonica rice varieties, and each pair of primers detected out 1-7 alleles with an average of 4.1. Four screened pairs of core SSR primers (RM190, RM18, RM297 and RM5414) could be used for distinguishing 19 japonica rice varieties and amplified 22 polymorphic fragments. Out of which, RM190 and RM18 primers had the strongest capacity for distinguishing 6 japonica rice varieties, while RM297 and RM5414 only could distinguish 2 varieties. RM297 could distinguish Changnongjing 5 and Ning 9103, and RM5414 could distinguish Nanjing 47 and Changjing 10-9. The genetic similarity coefficient among 19 japonica rice varieties varied from 0.408 to 0.857 with an average of 0.605, and 81.87% of all tested materials ranged from 0.500 to 0.700. UPGMA clustering results showed that 19 japonica rice varieties were clustered into 2 groups at 0.55 of genetic similarity coefficient. Furthermore, both 2 groups were classified into two subgroups at 0.620 and 0.570 of genetic similarity coefficient. [Conclusion] The japonica rice varieties in Taihu Lake area presented relatively higher genetic background comparability, and are not in abundance of genetic diversity. Therefore, introducing and taking advantage of new genetic resources should be strengthened to create japonica rice breeding materials. [ABSTRACT FROM AUTHOR]