三叶木通微卫星分子标记开发及评价

为了获得适于三叶木通遗传多样性和遗传结构研究的微卫星分子标记,该研究采用磁珠富集法构建了三叶木通微卫星富集文库。结果表明:在150个阳性克隆中发现了70个微卫星位点,富集效率为46.67%,其中含双碱基重复单元的序列占比为79.37%,三碱基和四碱基重复含有量较少。共设计引物63对,其中筛选出16对高多态引物,对1个三叶木通自然居群48个个体进行了遗传分析,结果显示位点的等位基因数为10~22个,观察杂合度和期望杂合度分别为0.370~0.792和0.724~0.936,多态性信息指数为0.725~0.919,表明以上引物均为高多态性引物。其中,12个位点偏离哈迪-温伯格平衡,呈现出纯合子过剩状态,这可能与哑等位基因和其它因素有关。综上结果表明,该研究所开发的16对引物能够用于三叶木通遗传多样性和遗传结构评价工作。

Isolation and characterization of microsatellite markers for Akebia trifoliata

Akebia trifoliata is perennial, woody vine producing large edible fruits. The high medicinal and nutritional values of A. trifoliata make it worthy of being exploited as a new crop. Wild resources of these species have been seriously deteriorated due to years of disorder planting and over-harvesting, thus wild germplasm resources protection and evaluation are particularly important. In order to obtain suitable molecular markers for genetic structure and genetic diversity of the existing resources, enriched SSR library was established using the magnetic bead enrichment procedure. Seventy SSR loci were obtained in 150 positive clones, and enrichment efficiency was 46.67%. Thereinto, sequences with two-base repeat unit accounted for 79.37%, far more than sequences with three-base and four-base. Sixteen pairs of high polymorphic primers were chosen in sixty-three pairs primers and characterized by 48 individuals collected in Lushan. The allele numbers per locus ranged from 10 to 22, and the observed and expected heterozygosity ranged from 0.370 to 0.792 and from 0.724 to 0.936, respectively, polymorphisms information content ranged from 0.725 to 0.919, which showed that the above primers were high polymorphic primers. Twelve pairs of primers deviated from Hardy-Weinberg equilibrium, showing excess of homozygotes, which might be related to null genes and other reasons. These molecular markers will contribute to evaluation on genetic diversity and population structure, lay a foundation for conservation and evaluation of A. trifoliata genetic resource.