菜心种质资源遗传多样性的SCoT分析

Analysis on genetic diversity of Chinese flowering cabbage(Brassica campestris L. ssp. chinensis Var. utilis Tsen et Le)germplasms based on SCoT markers

【目的】利用SCo T标记分析菜心种质资源的遗传多样性,为其分类和利用提供理论依据。【方法】搜集熟期和株色各异的33份菜心种质资源,利用筛选的12条SCo T引物对其进行遗传多样性分析。【结果】12条引物从33份菜心共扩增出83条带,引物多态性百分率变化范围为2.63%-57.89%,平均多态性百分率为36.00%;每条引物多态性条带变化范围为4-9条,平均3.4条;扩增片段大小为500-1500 bp。观察等位基因数（Na）为1.065,有效等位基因数（Ne）为1.254,Shannon’s信息多样性指数（I）为0.217,期望杂合度（He）为0.149,平均Nei’s遗传距离为0.428。AMOVA分析发现,81%的变异来源于品种内,19%的变异来源于品种间。聚类分析结果表明,在Nei’s遗传距离0.24处可将33份菜心分成两大类,第一类包括14个早熟品种、2个中熟和1个晚熟品种;第二类包括10个中晚熟品种和6个早熟品种。【结论】SCo T标记的分类结果与熟期分类结果较一致,多数菜心品种可根据熟期和SCo T标记归类;SCo T标记具有操作简单、重复性高、多态性较丰富等优点,可用于菜心遗传多样性研究的初步批量检测。

【Objective】The SCo T markers were used to assess genetic diversity of Chinese flowering cabbage germplasms, in order to provide theoretical basis for its classification and utilization. 【Method】Thirty-three Chinese flowering cabbage varieties were collected based on two phenotypic characters viz., maturity and color. Then 12 screened SCo T primers were used to assess genetic diversity of Chinese flowering cabbage. 【Result】A total of 83 DNA fragments were amplified with 12 SCo T primers. The polymorphic rate for each primer ranged from 2.63% to 57.89%, with average of 36.00%.The number of polymorphic bands was 4-9 for each primer, with average of 3.4. And the amplified fragment sizes ranged from 500 bp to 1500 bp. In addition, the number of different alleles（Na） was 1.065, the number of effective alleles（Ne）was 1.254, Shannon＇s Information Index（I） was 0.217, expected heterozygosity（He） was 0.149, and the average Nei＇s genetic distance was 0.428. AMOVA analysis showed that 81% variation was within varieties and 19% variation was among varieties. The cluster analysis showed that 33 Chinese flowering cabbage varieties were classified into two clusters at the Nei＇s genetic distance of 0.24. Cluster 1 contained 14 early-maturing varieties, 2 medium-maturing varieties and 1late-maturing variety. Cluster 2 contained 10 medium-maturing and 6 early-maturing varieties. 【Conclusion】The clustering results based on SCo T markers were nearly consistent with that based on maturity characteristics, it is indicated that the most of Chinese flowering cabbage varieties can be clustered based on maturity characteristics or SCo T markers. Futhemore, the SCo T markers were characterized by easy operation, high reproducibility, abundant polymorphism, which can be used to detect preliminarily genetic diversity of Chinese flowering cabbages in batches.