藜科6种耐盐植物遗传多样性的EST-SSR分析

EST-SSR Based Genetic Diversity Analysis on Salt Tolerant Plants from Six Species in Chenopodiaceae

利用EST-SSR标记分析了藜科6种耐盐植物的遗传基础和遗传多样性,以期为藜科耐盐植物遗传育种提供快速、可靠的分子标记辅助选择工具。采用31对藜科海蓬子属和碱蓬属的EST-SSR引物对藜科6种植物进行PCR扩增,其中16对引物得到较好扩增,引物通用率为51.6%,共检测到18个多态性位点,每位点等位基因数2~4个,多态性丰富。进一步采用Nei’s遗传距离聚类分析表明6种植物可以分为3组,主成分分析也支持上述分组,而且DY529957、DY529903和DY5298853个EST在分组中贡献率最高。经与GenBank中序列相似性比对,前两者分别编码生长素抑制蛋白（Auxin-repressed protein,ARP）和植物防御素（Defensins,Def）,都参与植物逆境胁迫响应,但分属于不同代谢途径;后者则编码未知蛋白。总体而言,16对SSR引物在藜科6种植物间具有较好的通用性,能够揭示该6种植物间广泛的遗传多样性,及其存在不同耐盐机制提供分子证据。

This report focus on EST-SSR based evaluation of genetic diversity in salt tolerant plant from six species in Chenopodiaceae.Thirty-one pairs of EST-SSR primers were designed according to ESTs sequence collected from Salicornia and Suaeda genera.Only sixteen out of all primer pairs successfully amplified the DNA fragments by using PCR procedure across all samples,which demonstrated 51.6% over all primers was transferrable.Total 18 polymorphic loci were detected by the 16 primer pairs,and allele number at each locus ranged from 2 to 4,indicating a wide range of genetic diversity.Clusterring analysis based on Nei＇s genetic distance showed that the six plants could be grouped into three clades,and the division was confirmed by principal component analysis.Moreover,this grouping profile was mainly attributed to polymorphism of three ESTs,e.g.DY529957,DY529903 and DY529885.According to the sequence similarity,the three ESTs were assumed to encode an auxin-repressed protein（ARP）,defensins（Def）and hypothetical proteins,respectively.Both ARP and Def were well documented to be involved in salt stress responds but form different pathways in plants.This result implies that different mechanism might be evolved among the genera.