利用分子标记分析遗传多样性时的玉米群体取样策略研究

利用分子标记技术对玉米种质资源进行遗传多样性分析对种质资源的保存和利用具有重要的指导意义。但是，在对地方品种和育种群体这些开放授粉群体进行大规模遗传多样性分析时，取样方法将会严重影响到研究结果和工作效率。本研究用2个育种群体和3个地方品种为试材，利用微卫星(SSR)标记对每个群体100个个体及其组成的不同随机混合样品进行了分子检测。结果表明，不同群体的群体内遗传变异大小存在差异；相同数目的个体随机混合的不同样品间的检测结果基本相同；不同数目的个体混合的样品间存在一定程度的差异，并且与材料本身的遗传变异大小有一定关系。考虑到结果的科学性和工作的可行性，建议在利用分子标记(如SSR)进行地方品种和育种群体的遗传多样性评估时，随机选取30个个体组成混合样(或用15个个体组成2个混合样)来代表1个地方品种或育种群体进行分子鉴定。

Sampling Strategies of Maize Populations when Molecular Markers are Used in Genetic Diversity Analysis

Analysis of genetic diversity in maize germplasm is of great importance to conserving and utilizing these valuable genetic resources. However, when a large-scale analysis of genetic diversity in maize landraces and breeding populations which are genetically heterogeneous is conducted, the choice of sampling methods will seriously affect research results and efficiency. To solve the problem of sampling methods, individuals and bulking samples of different individuals of two breeding populations and three landraces were selected to be molecularly characterized using microsatellite (SSR) markers. The results showed that there were differences of intra-population genetic variability among different populations. Different bulking samples with the same number of individuals showed similar results, but bulking samples with different individuals presented some different results to some extent and the differences seemed to associate with the extent of genetic variability of the entries. Considering both scientific significance and research feasibility, we suggest that one bulk from randomly chosen 30 individuals (or two bulks each from randomly chosen 15 individuals) representing one population be genotyped when genetic diversity of maize landraces and breeding populations is assessed based on molecular markers, e.g. SSR.