The Wild Germplasm Resources Investigation And Evaluation Of Pyrus In Shandong Province

Wild pears are important forest tree germplasms resources in Shandong Province, and based on comprehensive investigation, genetic diversity and phenotypic diversity were studied to provide ground for better protection, in addition, the community study of precious Pyrus hopeiensis and Pyrus trilocularis provided ground for preservation development and utilization of wild pear germplasms resources. The main achievements as followed:1. Genetic diversity of 40 germplasm from wild pear was studied by sequence-related amplified polymorphism(SRAP), and the research results were showed as follows: 199 loci were identified with 14 SRAP primer combinations out of which 196 were polymorphic. The proportion of polymorphic loci(PPL) was 98.49%. Nei's gene diversity(H) was 0.286,Shannon's Information index(I) was 0.4421, which showed a rich genetic diversity in pear.Coefficient of genetic differentiation(Gst) was 0.5266 suggested that 52.66% variation occurred among different species and 47.34% variation occurred among within species, and the Nei's genetic identity and genetic distance were 0.5025-0.9263 and 0.0766-0.6681;the P.hopeihensis, Pyrus ussuriensis, and Pyrus phaeocarpa formed a branch firstly, and provide ground for the origin of P.hopeihensis from DNA level; the analysis result of PCOA was similar with cluster analysis, and the former directly showed the relationships between all groups.2. The phenotypic diversity analysis was carried out on the wild pears of Shandong Province. 9 traits such as leaf length, leaf width were selected to analysis phenotypic diversity and the results of variance analysis indicated that: there were 9 traits had significant difference between populations(P<0.01). Mean value of coefficient of variation(CV) is31.37%, and the CV of Pyrus.calleryana is the highest. Mean value ??of phenotypic differentiation coefficient(VST) is 65.83, indicating that 65.83% of the variation existed among species while the proportion within species reached 34.17%, which was much lower than that among species.3. The community composition and structure of P.hopeiensis and P.trilocularis were studied by methods of phytocoenology. The results showed that: the communities were representative warm temprate deciduous forests. The vertical structure was clear and community structure was stable, the abundance advantage of common species was significant,but the natural regeneration condition was bad and the setting percentage and seedling treeswere few. The original habitat community composition and structure should provide the basis for the rare and endangered plants regression, such as P.hopeiensis and P.trilocularis, and the returning land was similar to the original habitat as much as possible.The wild pears population accumulated high phenotypic diversity and genetic diversity.The community levels clear and structure is stable. Protection procedure of endangered pears can base on on-site conservation with ex situ conservation and germplasm bank to maximize genetic diversity protection. Based on the protection of wild pears, we should carry on the comprehensive development and utilization by developing the scientific value and industrial value, and stick to the guideline of "paying equal stress on protection and development".