Assessment On Genetic Diversity Of Pea(Pisum Sativum L.)Core Collections Germplasm

Field Pea (Pisum sativum L.) is the fourth largest legume crop globally, and China is the most pea productive country in the world.The conservation amount of pea gennplasm in our country increased rapidly as the continuing of international germplasm introduction project in recent years, therefore, it is very important to know the genetic diversity of the pea germplasm we have. The SSR marker is a common molecular method which was widely used in the plant genetic diversity assessment, but the development of pea SSR markers was far behind other crops previously. After designing and screening the339pea SSR markers,30SSR markers had been successfully obtained and used in the evaluation of295Chinese pea core collections and310overseas pea core collections from the USDA with the assistance of10phenotypic traits. The main results were summarized as follows:1.30highly polymorphic SSR markers had been successfully obtained from the screening of total339pea SSR markers, the most suitable annealing temperature of each markers had been identified with the establishing of the optimizatal PCR amplification system.2.The morphological marker showed that the genetic diversity of two pea core collections were abundant and both of them had good representativeness, both the variation scale and genetic diversity level of overseas core collections was higher than native core collections.Based on the analysis of10phenotypic traits, the native core collections had better performance than overseas core collections, the average CV (Coefficient of variation) and I(Shannon’s index) were41.43and1.91in overseas collections, and30.23and1.75in native collections respectively.601pea core collections were divided into4populations by Structure software based on the morphological data, the populations were not obviously correlated to their geographical origin.3. The SSR markers showed that the genetic diversity of two pea core collections were abundant, the genetic diversity of overseas collections were higher than native collections. A total of259observed numbers of alleles(na) has been detected based on the30screened SSR markers, with8.63na per SSR marker; the average value of I was1.52in overseas collections, which is larger than native collections with1.20in average. Based on SSR markers with the structure software analysis, the native collections were divided into3populations, the populations were closely correlated to theirsowing origin; the overseas collections and overall collections were divided into4and7populations correspondently and their populations were not obviously correlated to their geographical origin.4. Based on the SSR markers,1258rare na were detected in466pea core collections with8of them have unique na.