中国苜蓿地方品种种子贮藏蛋白标记：遗传多样性的研究

利用ＳＤＳ－ＰＡＧＥ方法对中国１８个地方苜蓿品种和北美９个苜蓿基本种质来源的代表品种，各选２０粒种子进行贮藏蛋白分析。结果表明，苜蓿品种内和品种间均具明显的多态性，但采用混合样分析则掩盖了品种内的多态性。

Study on the Genetic Diversity of the Alfalfa Local Varieties (Medicago sativa L.) in China: Seed Storage Protein Markers

Genetic diversity of the 18 alfalfa local varieties in China and the 9 alfalfa varieties repre-senting the 9 basic alfalfa germplasm sources in North America were studied using seed storage proteinmarkers. Results showed that: Obvious polymorphisms within and among varieties can be revealed usingelectrophoresis of alfalfa single seed samples. Meanwhile, polymorphisms within varieties are concealedwhen using bulk samples. Monomer weights of alfalfa seed storage proteins are 21. 7 ~ 83. 8KD. 25 stableand distinct monomers are scored as 1 for present and 0 for absent, and frequency of each monomer iscalculated based on these data. Among the 25 monomers, 12 are polymorphic. Difference between vari-eties is reflected hy the different frequencies of different monomers. Total gene diversity (HT), polymor-phic loci rate (P)and gene diversity within varieties (Hs) of the 18 alfalfa local varieties in China arehigher than those of the 9 alfalfa varieties in North America. These results indicate that the varieties inChina are mere heterozygous and genetic variation within varieties is relatively larger. Analysis of genedifferential coefficient(GST) indicating that genetic variation of Medicage sativa is mainly exits within va-rieties. This charateristic is related to the breeding system (out-breeding) of Medicage sativa. GST of the18 alfalfa local varieties in China is smaller than that of the 9 alfalfa varieties in North America, indicat-ing that more gene communications occurred between the alfalfa local varieties in China, and variationwithin varieties takes up more of the total genetic variation. These results variety that the geneic structureof alfalfa varieties is also related to their geographic distribution and sources.