东亚甘薯品种AFLP标记遗传差异研究

Genetic Difference of Sweetpotato Cultivars in East Asia as Revealed by AFLP Marker

甘薯是世界上重要的粮食、饲料、工业原料和新型能源作物,由于遗传背景知识的缺乏,甘薯遗传改良受到限制,东亚是世界上甘薯种植最集中的区域,因此有必要了解东亚甘薯品种的遗传多样性程度和遗传差异。本研究利用AFLP标记对43份来自东亚地区的甘薯育成品种遗传多样性进行了分析。10对AFLP引物扩增出307条谱带,其中多态性谱带占71.7%,平均每对引物扩增22.0条多态性带,表明AFLP标记是一种甘薯遗传多样性分析的高效方法。供试品种间遗传距离为0.0938～0.3359,平均为0.2302,利用UPGMA法可以将供试品种聚为5个组群,表明供试品种遗传多样性程度丰富,东亚甘薯育成品种之间具有较明显的遗传差异。不同国家或地区品种间的遗传距离高于国家或地区品种内的遗传距离。韩国品种与其它东亚国家或地区品种间遗传距离较远。供试品种中,中国大陆品种平均遗传距离最小。作者认为我国甘薯品种改良,应注重与韩国资源的交换,同时在亲本组配中避免少数品种人为过度利用,以保持甘薯品种的遗传多样性,提高甘薯品种改良进度。

As an important material of industry, new energy resource, food and forage crop, sweetpotato （Ipomoea batatas （L.） Lam.）, is desired to increase production, but it is often limited by a lacking knowledge in conventional hybridization. East Asia is the biggest region to plant sweetpotato in the world. Therefore, it is necessary to assess genetic diversity and genetic difference of sweetpotato in East Asia. In this study, 43 sweetpotato cultivars of East Asia were assessed by using AFLP （amplified fragment length polymorphism, AFLP） marker to understand their genetic difference for sweetpotato improvement and germplasm exchange. Ten AFLP primer pairs generated 307 bands, in which 71.7% bands were polymorphic with an average of 22.0 polymorphic bands per primer, indicating that AFLP marker was one of the higher efficient methods to analyze the genetic diversity of sweetpotato. Wide genetic distances were found among the tested cultivars, ranged from 0.093 8 to 0.335 9 with an average of 0.230 2. The UPGMA cluster analysis classified these cultivars into 5 groups. Cultivars from different countries or regions of East Asia had obvious differences in terms of genetic distance. The genetic distances between cultivars of different countries or region were larger than those within cultivars of same countries or region. The cultivars from Korea were far from other regions of East Asia, and the cultivars from Chinese mainland had the lowest mean genetic distance. These results suggest that crosses between different regional cultivars should be emphasized in sweetpotato breeding in East Asia, and germplasm exchange With Korea should be strengthened in the future in China.