用SRAP标记分析中国甘蓝型油菜品种的遗传多样性和遗传基础

Analysis of Genetic Diversity and Genetic Basis of Chinese Rapeseed Cultivars (Brassica napus L.) by Sequence-Related Amplified Polymorphism Markers

【目的】探讨中国甘蓝型油菜遗传多样性和遗传基础。【方法】采用SRAP（sequence-related amplifled polymorphiSill）标记对建国以来不同时期选育的130个品种进行分析。【结果】25个SRAP引物组合共扩增到509个谱带、123个多态性带；多态性带的比例为24％。每对引物组合的谱带数和多态性带数分别为20．4个和4．9个。在遗传距离为0．12处，将130个甘蓝型油菜品种（系）分为A、B、C、D4个类群，其中78．5％的品种归入C类。C类又可在遗传距离0．10处分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ5个亚群，又有58．5％的品种归入Ⅲ亚群。说明我国近60%的甘蓝型油菜品种遗传多样性较匮乏。遗传基础分析结果表明，20世纪80年代前育成的甘蓝型油菜品种的遗传基础最窄，80年代最宽，90年代略有下降。进入21世纪，品种间的遗传基础进一步下降。差异显著性测验结果表明，1991～2000年间与2000年以后育成的品种间的平均遗传距离差异不显著，80年代前育成品种与80年代育成的品种平均遗传距离间差异达到0．01显著水平，80年代与90年代育成的品种间遗传距离差异达到0．05的显著水平。我国育成的品种间的遗传距离与引进品种间的遗传距离差异达到0．01的极显著水平。【结论】SRAP标记是一种经济、有效和可靠的分子标记手段。

[Objective] In order to investigate the Genetic diversity and genetic basis of rapeseed （B. napus L.） in China, [Method] total 130 accessions developed in different years since 1949 were analyzed using SRAP （sequence-related amplified polymorphism） markers. [ Result ] A total of 509 amplified fragments and 123 polymorphic fragments were detected by applying 25 SRAP primer combinations. The polymorphic fragment percentage was 24%. The number of amplified fragments and polymorphic fragments per primer combination were 20.4 and 4.9, respectively. 130 B. napus accessions were divided into four groups of A, B, C and D at genetic distance of 0.12. About 78.5% of total accessions were classified into group C. Group C could also be divided into Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ sub-groups at genetic distance of 0.10. About 58.5% of total accessions were classified into sub-group Ⅰ indicating the genetic diversity of 58.5% accessions of total was poor. The results demonstrated that the genetic basis of B. napus L. accessions released before 1980 was the narrowest while those released in 1980s reached the widest. In 1990s, the genetic distances of B. napus L. accessions declined again. The genetic basis of B. napus L. accessions narrowed further after 2000. Though the difference of mean genetic distance between accessions bred in 1990s and after 2000 did not reach a significant level, the difference in mean genetic distance in different periods was at 0.01 or 0.05 significant level. The difference in mean genetic distance between accessions bred inChina and introduced from abroad reached a significant level at 0.01. [Conclusion] All these results showed that SRAP markers were economic, effective, and reliable.