SCoT分子标记在猕猴桃遗传多样性分析与变异鉴定上的应用

摘要

我国猕猴桃(Actinidia)种质资源极其丰富,可为猕猴桃遗传改良和资源利用提供广泛的背景材料,而从实生苗群中筛选变种是猕猴桃新品种培育途径之一.本研究以17份猕猴桃品种(系)(其中2份红阳变异系、1份金桃变异系)为材料,采用目标起始密码子多态性(start codon targeted polymorphism,SCoT)对其遗传多样性和变异进行分析.结果表明,基于优化后的适宜于猕猴桃SCoT-PCR反应体系,从64条引物中筛选出42条引物对17份猕猴桃材料扩增出487条清晰的条带,其中多态性条带为470条带,平均多态性比率为95.1％.17份猕猴桃材料之间的遗传距离范围在0.153～0.693,平均值为0.492.变异株桂乐1号、桂乐2号与对照红阳的遗传距离分别为0.276和0.299,金桃变异与金桃的遗传距离为0.539,3个变异株系均与对照有一定的亲缘关系与遗传距离.聚类分析表明,在遗传距离为0.460的水平上,可以将17份猕猴桃材料分为4组.桂乐1号、桂乐2号与对照红阳归为第Ⅲ组,金桃变异与对照金桃则未能聚为同一组.SCoT分子标记可以对猕猴桃性状变异进行初步鉴定,为进一步开展变异新品种的早期鉴定和保护提供技术参考,以及为猕猴桃种质资源遗传多样性分析及其分类提供理论支持.%There are various Actinidia genotypes in China,which provides broad breeding materials for creating new cultivars,and the selection of variant lines from the seedling population is one of the approaches for the cultivation of new Actinidia varieties.The genetic diversity and variation of 17 Actinidia cultivars (2 'Red sun'variant lines and 1'Jin tao'variant line) were analyzed by using SCoT marker technology.The results showed that based on the optimized SCoT system,forty-seven primer combinations were selected from 64 SCoT primers for their amplification with clear bands and significant difference from 17 Actinidia cultivars.A total of 487 bands were amplified,in which 470 bands were polymorphic (95.1％).The value of genetic distance was ranged from 0.153 to 0.693,with the average of 0.492 for 17 Actinidia cultivars.And the values of genetic distance of variant lines'Guile 1','Guile 2'to the control'Red sun'were 0.276,0.299,respectively,while'Jintao'variant line to the control was 0.539.The resulted showed that two'Red sun'and one'Jin tao'variant line were varied from the control.Moreover,the 17 Actinidia cultivars could be classified into 4 groups based on the distance of 0.460 using the cluster analysis.Two variant lines ('Guile 1','Guile 2') and the control 'Red sun'belong to the group Ⅲ.And'Jin tao'variant line and the control'Jintao'were not within the same group,which needs to be confirmed by further study.These results showed that the variation of Actinidia cultivars could be preliminary evaluated by SCoT marker technology,which provide basis for early evaluation and protection of new variation line and further research and application on genetic resources in Actinidia.