关键词: 水稻, 半糯粳稻, DNA指纹图谱, 分子标记

Abstract:

【Objective】 A set of variety DNA fingerprint identification system based on the core markers of genes regulating rice important traits was constructed, which will establish a foundation for strengthening the germplasm management and protection of the mainly promoted semi-waxy japonica rice varieties with high eating quality.【Method】 34 semi-waxy japonica rice varieties mainly cultivated in Jiangsu, Zhejiang and Shanghai were used as the test materials. The key differential sequence sites in genes regulating rice important traits were screened and core SNP or InDel markers were developed through multiple methods such as polymorphism testing of existing markers, gene sequence alignment from public databases and genome resequencing. SNP markers were developed into simple PCR markers based on electrophoretic bands by As-PCR technology. Genotype information was obtained by electrophoretic band characterization and type analysis, and the DNA fingerprint database of the semi-waxy japonica rice varieties was constructed..【Result】 54 core markers derived from 40 key genes regulating rice important traits were obtained, including 18 SNP and 36 InDel markers; 155 characteristic and effective bands were identified by 54 markers in the tested rice varieties, which were transformed into 155 0/1 data sites. The DNA fingerprint database of each variety was established and could distinguish it from all tested varieties. Genetic diversity analysis showed that the variation range of genetic similarity among varieties was 0.47-0.90, among which the lowest similarity coefficient was detected between Nanjing 7718 and Suxiangjing 100, while the highest similarity coefficient was detected between Nanjing 9308 and Nanjing 9036, among which there were 8 differential data sites. Genetic relationship analysis indicated that 34 varieties were divided into 6 branches, of which Nanjing 7718 was an independent branch, suggesting it has a distant relationship from other varieties. Further verification of the identification effect of core markers showed that the set of markers could effectively distinguish 14 new semi-waxy japonica rice varieties. The cluster diagram showed that they were distributed in three groups of Ⅱ, Ⅲ and Ⅳ, confirming the differences of genotype information among varieties; using this set of markers, the authenticity of an unknown semi-waxy rice variety was also identified. According to genotype and cluster analysis, it was determined as Nanjing 9108.【Conclusion】 After optimization and screening, 54 core markers that could accurately distinguish all the tested semi-waxy japonica varieties were obtained, and developed into simple PCR markers detected by electrophoresis. Using this set of marker combinations, the DNA fingerprints of 34 semi-waxy japonica varieties in Jiangsu, Zhejiang and Shanghai were constructed.

Key words: rice (Oryza sativa L.), semi-waxy japonica rice, DNA fingerprints, molecular markers