中国甘薯主要亲本遗传多样性的ISSR分析

Genetic Diversity in Main Parents of Sweetpotato in China as Revealed by ISSR Marker

用ISSR标记分析了中国62份甘薯主要亲本的遗传多样性,明确了其遗传差异。结果表明,17个ISSR引物共检测出490条多态性谱带,平均每条引物检测出28.8条多态性谱带,说明ISSR标记是评价甘薯遗传多样性的有效途径之一。62份中国甘薯主要亲本遗传距离为0.158-0.924,平均为0.574,通过UPGMA法,可以聚为2大类,一类为国内自育亲本,一类为外引亲本,说明中国甘薯主要亲本遗传多样性较丰富,其中自育亲本与外引亲本之间遗传距离较远;亚洲亲本遗传多样性高于非洲和美洲亲本,并且与其他亲本间遗传距离较远;亚洲品种中,中国大陆亲本遗传距离最小,为0.419,与来自中国台湾的亲本差异较小,但与外引亚洲亲本遗传距离较远。因此,中国在未来甘薯育种中,可以国内自育亲本与外引亲本以及外引亚洲亲本与外引其他亲本配制组合,拓宽中国甘薯品种的遗传背景。

As an important material of industry and new energy resource crop as well as food and forage, increase in production of sweetpotato[lpomoea batatas （L.） Lam.] is desired, but this goal is often limited by a narrow genetic background of the parents in conventional hybridization. It is, therefore, necessary to assess genetic diversity in main parents of sweetpotato. In this study, 62 main sweetpotato parents in China were assessed by using inter-simple sequence repeat （ISSR） marker to understand their genetic difference for exact parent selection in breeding. Seventeen ISSR primers generated 490 polymorphic bands with an average of 28.8 polymorphic bands per primer, indicating that ISSR marker was one of efficient methods to analyze the genetic diversity of sweetpotato. Wide genetic variations, ranged from 0.158 to 0.924 with an average genetic distance of 0.574, were found among the tested cultivars. The UPGMA cluster analysis classified the materials into 2 groups, domestic and exotic cultivars. These main parents had high genetic diversity, and domestic cultivars were far from exotic cultivars in terms of genetic distance. The genetic diversity of Asian cultivars was higher than that of the cultivars originally from Africa and America. The cultivars from Chinese mainland had the smallest genetic distance （0.419）, and were close to the cultivars from Taiwan, China, but far from exotic Asian cultivars. These results suggest that crosses between domestic and exotic parents should be emphasized in sweetpotato breeding in China.