中国花生地方品种与育成品种的遗传多样性

Comparison of Genetic Diversity between Landraces and Breeding Varieties in Chinese Peanut Mini Core Collection by SSR Markers

以中国花生小核心种质中涉及来源于中国本土的145份地方品种和67份育成品种为材料,应用SSR技术从206对SSR引物中筛选出25对扩增效果好的多态性引物进行检测,并对其进行遗传多样性分析比较。结果表明：（1）地方品种与育成品种各具有特殊带型及各自独特的遗传特性。相似系数和多态性信息量均表明,地方品种的多样性比育成品种丰富,其中：地方品种之间的相似系数为0.57~0.99,平均0.795,多态性信息量0.530 0;育成品种之间的相似系数0.63~0.99,平均0.810,多态性信息量0.463 3。地方品种与育成品种之间的平均相似系数为0.794,变异范围0.56~0.99。（2）对不同生态区来源的分析表明,除黄河流域外其他各生态区地方品种的观测等位基因数和遗传多样性指数（分别为2.740 7~3.518 5和0.816 4~0.879 4）均比育成品种的对应值（分别为1.701 2~2.145 6和0.482 9~0.802 2）大,并以长江流域生态区地方品种的观测等位基因数和遗传多样性指数最大,分别为3.518 5和0.879 4。（3）聚类分析结果表明,花生核心种质中,中国本土资源分为3个品种群,即地方品种密枝亚种群、地方品种疏枝亚种群和育成品种群,与花生的亚种分类一致。（4）通过遗传多样性分析,鉴定出一批遗传差异较大的材料,其中zhh1398与zhh0041的遗传差异最大,相似系数为0.56,为花生品种的遗传改良及作图群体的构建奠定了基础。

Evaluation of genetic diversity is a basic work to explain the genetic relations among variety types or germplasm sources and to reveal the inheritability mechanism of potential elite genes.A set of peanut mini core collection consisting of 298 accessions was previously established in China.212 Chinese native landraces and breeding varieties involved in the mini core collection were genotyped with SSR markers in the present study.Twenty five polymorphic SSR markers were screened from a total of 206 primer pairs.The results derived from SSR data were as following：（1）The genetic variation of landraces was richer than that of breeding varieties based on the similarity coefficient and polymorphic information content（PIC）.The similarity coefficients between genotypes among the landraces and breeding varieties and between landraces and breeding varieties were 0.57 to 0.99 with average of 0.795,0.63 to 0.99 with average of 0.810 and 0.56 to 0.99 with average of 0.794,respectively.The PIC of the landraces and breeding varieties were 0.530 0 and 0.463 3 respectively.（2）The observed number of alleles and Shannon＇s genetic diversity index in landraces were higher than those in breeding varieties for the all ecological regions（The formers were 2.740 7~3.518 5 and 0.816 4~0.879 4,respectively and the latters were 1.701 2~2.145 6 and 0.482 9~0.802 2,respectively） except for Yellow River Basin.Moreover,the observed number of alleles of 3.518 5 and Shannon＇s genetic diversity index of 0.879 4 in landraces were the highest among the all accessions.（3）Results of principle component analysis using software NTSYS-PC based on the SSR data indicated that Chinese native accessions were classified into 3 groups including groups ssp hypogaea,ssp fastigiata and breeding varieties and lines which was in consistent with botanical taxonomy.These three groups have different genetic diversity.（4）Some genotypes with big variation were identified including the genotype pair of zhh1398 and zhh0041 with the smallest similarity coefficient.