板栗野生居群与栽培品种间叶绿体微卫星遗传差异初探

对24对epSSR通用引物进行筛选,选用4对呈现多态性的引物对板栗的4个野生居群和9个地方品种群进行遗传分析.结果表明:4个位点在128个样本中扩增等位基因数(Na)平均为3,有效等位基因数(Ne)平均为1.635,期望杂合度(He)平均为0.381,各遗传参数值远低于核基因组对群体研究的相应值.4个等位基因共组合出8种单倍型,既有共享率超过57%的单倍型,也存在特异稀有单倍型,其中陕西汉中与安徽广德板栗天然野生居群,具有较高的单倍型多样性,分别为0.671和0.781,明显高于其他地区,显示两地是板栗的分布及遗传多样性中心.基于cpSSR数据,对板栗地方品种与天然野生居群间的遗传结构、关系及地方品种的起源进行初步探讨.

Diversity of Chloroplast DNA SSRs in the Wild and Cultivated Chestnuts(Castanea mollissima)

In this study 24 cpSSR primer pairs were screened, and four pairs were found producing DNA fragment length polymorphism from the tested populations of Castanea mollissima. In order to estimate genetic variation and genetic structure of chestnut, we surveyed four wild and nine cultivated populations in China with cpSSR markers. The results showed there were 3 average number of alleles (N), 1.635 effective number of alleles (N_e) and 0.381 expected heterozygosity ( H_e) , from 4 loci in 128 samples. Apparently, the parameters of cpSSR loci were much lower than those revealed by nuclear SSRs. The combinations of all the length variants of alleles from four cpSSR loci finally presented eight haplotypes in the nine populations of C. mollissima. The Qinling mountainous region and Tianmushan mountainous regions possessed the richest haplotype diversity (respectively 0.671 and 0.781) . Based on cpSSR data, we estimated the genetic structures of the wild and cultivated chestnut populations and discussed the origins of the cultivated C. mollissima in China.