Analysis Of Genetic Diversity And Relationship Of Nectarine And Crisp Peach By Molecular Markers

Peach[Prunus persica (L.) Batsch],which was an important subgenus belonging to Prunus,was originated from in China.Eich germpalsm with great diversity was found here due to evolution, cultivation and breeding in a long historical process. These germplasm was important for new variety breeding and germplasm innovation, and was the backbone for the development of peach industry. Evolution and genetic relationship conclusions of different peach populations was evaluation by morphologic, cytology, palynology, isoenzyme, as well as some DNA markers, such as RAPD. As a stable, polymorphic and co-dominant marker, SSR and SRAP were used widely in appraising peaches from America and Europe. Therefore, SSR and SRAP were also used in this paper to appraise 80 nectarines, 10 other peach varieties and 45 crisp peaches conserved in National Peach Germplasm Repository in Nanjing. The results went as followes:Firstly, the results of genetic diversity and relationship of nectarines identified by SSR and SRAP.In order to appraise genetic diversity and relationship of peach, 80 Nectarines, as well as 10 other peach varieties, were used as plant material in this paper. A total of 73 alleles were amplified by 25 primers distributed on eight linkage groups on Prunus reference map.68 alleles showed polymorphism, and the percentage of polymorphic bands (PPB) was 93.15%. The Nei′s gene diversity index (He) and Shannon′s information index(H0)of Nectarines varieties were 0.2784 and 0.4210, respectively. A total of 213 alleles were amplified by 60 pairs of SRAP primers. 107 alleles showed polymorphism, and the percentage of polymorphic bands (PPB) was 50.23% .And the Nei′s gene diversity index (He) and Shannon′s information index(H0)of Nectarines varieties were 0.1384 and 0.2136. Compared with SRAP, SSR has a good stability, high polymorphism and primers specificity, and so on.Groups cluster analysis based on the UPGMA method indicated that although exists a certain degree of cross-species, the cluster graph can better reflect the characteristics of ecological zoning, there is a certain correlation between nectarine varieties and geographical origin of the cluster .Secondly, the results of genetic diversity and relationship of crisp peaches identified by SSR.45 crisp peach varieties were used as plant material in this paper. A total of 152 alleles were amplified by 25 primer pairs distributed on eight linkage groups on Prunus reference map. 146 alleles showed polymorphism, and the percentage of polymorphic bands (PPB) was 96.05%. The Nei′s gene diversity index (He) and Shannon′s information index(H0)of crisp peach varieties were 0.2283 and 0.3609, respectively. Crisp peach varieties from the area along Yangtzi river had the highest Nei′s gene diversity index (0.2211) and Shannon′s information index(0.3476), followed by subtropical zones in South China and Yunnan-Kweichow Plateau , the lowest from the North China Plain. Groups cluster analysis based on the UPGMA method indicated that there was some relationship between crisp peach varieties and ecological zones, but not all varieties were in comformity with geographic origin and some from different ecological zones overlapped. Crisp peach varieties from the Yangtzi River and Yunnan-Kweichow Plateau had closer genetic relationship, followed by subtropical zones of South China, as far as the North China Plain. The results preferred the opinion that the crisp peach varieties from Yangtzi River may not only origin from the north China, but also from the Yunnan-Kweichow Plateau and subtropical zones in South China.