Genetic Diversity Analysis Of Purple-fleshed Sweetpotato "Ipomoea Batatas (L.) Lam." Cultivars

Purple-fleshed sweet potato is a special breed of Ipomoea batatas(L.)Lam. With unique hereditary character and economic value which is well known for its purple-fleshed tuberous root. Chemical analysis shows that the pigment which extracted from purple-fleshed sweet potato is cyaniding derivatives. The pigment is high-grade pigment.In this paper, purple-fleshed sweet potato of genetic diversity was analyzed by morphological makers and ISSRs maker. The genetic diversity among the introduced strains and breeding lines of purple-fleshed sweet potato was analyzed in this paper. The diversity of purple-fleshed sweet potato pigment distribution in different strains laid a technical foundation for carrying on the variety identification and genetic breeding. The distribution of the purple pigment in different strains between purple-fleshed and white-fleshed sweetpotato was investigated in this paper. Moreover, the diversity of pigment distribution in different organs and tissues provided the materials for the investigation of pigment biosynthesis and the mechanism of manipulation.The research work and results were reported as following.1. Twenty five sweetpotato varieties (strains) were distinguished clearly based on 20 morphological traits. The result suggesting that Chinese sweetpotato possessed sufficient genetic variation.2. This Paper optimized the reaetion system of ISSR fitting for analyzing the genetiec diversity of purple-fleshed sweetPotato. Nine ISSR primers were respectively chosen for they showed clearly, reproducible amplification and distinct polymorphisms from 32 primers.9 ISSR primers generated 80 bands, of which polymorphic bands number is 54, the percentage of polymorphism in all bands equaled 67.5%. Any amplified band was treated as a character, and the binary data matrix set out according as the bands existed or not. The Jaccard coefficient was worked out by using NTsys software.3. According to the clustering analysis of morphological makers and ISSRs maker’s results, 25 sweetPotato cultivars were completely separated. The genetic diversity levels of purple-fleshed sweetpotato breedig lines was higher than that in introduced breeds.4. The distribution of the purple pigment in 14 (strains) between purple-fleshed and white-fleshed sweetpotato was investigated in this paper. The result showed that there were significant differences on pigment distribution in strains and organs. The storage root of purple-fleshed sweetpotato is the predominant organ accumulating pigment. The uneven distribution of pigment was detected in storage root. The difference of the contents of pigment also observed from morphology apex to morphology base in the trailing part of purple-fleshed sweet potato.