Construction Of Core Collections And Genetic Diversity Analysis Of Arachis Hypogaea Cultivar In China

Peanut is an important oil and economic crop. China is the largest country of peanut production in the world. China has collected and saved more than7,000peanut resources, and evaluated its main botanical characters systematically, such as agronomic characters, seed quality traits, disease resistance and insect resistance. But the introduction, exploration and utilization efficiency of germplasms is not high. In order to confirm the genetic diversity of different sources of germplasms, research the origin and evolution of peanut, this study constructed a core collection of China cultivar peanut gremplasms, then analyzed its genetic diversity, and explored the application of SSR molecular marker technology. This study has an important theoretical and practical significance in accelerating the development and utilization of peanut germplasms in China, and in enchanceing explore efficiency of new peanut genetic sources. The main results are as follows:1. Chinese cultivar peanut germplasms which are more than2,700were grouped by botanical types and geographical origins. The core collection construction method was determined after the comparison of different sampling method and sampling ratio, it is random sampling within class after clustering. The core collection been constructed has259germplasms, accounted for9.45percent of the total resources, and covered all types of102phenotypic variation. The analysis for different triats use statistical methods, such as T test, F test, Chi-square test and phenotypic frequency distributions, showed that the core collection can represent the entire collection, and the core collection will play an important role in the utilization of cultivar peanut germplasm resources. Clustering analysis can distinguish heterogenous germplasms from each other, and classify homogenous germplasms as a class. The core collcetion has high genetic diversity in disease resistance.2.134pairs of SSR primers with clear bands and obvious main strip were screened.134pairs of SSR primers amplified846allelic variations from85peanut resources, each pair of primers amplified allelic variation range from2to16, the average is6.31. The genetic diversity index of each pair of primers range from0.349to2.281, the average is1.361. The polymorphism information content of each pair of primers range from0.132to0.867, the average is0.609. It is showed that the85peanut resources have high genetic diversity. Both the clustering result of phenotypic datas and SSR molecular marker datas can divide85germplasm resources into2categories which are ssp.fastigiata and ssp.hypogaea, but the difference of molecular level is better to breeding research, especially in breeding for disease resistance.3. According to correlation analysis between different number of allelic variations and entire allelic variations of134SSR molecular markers, we can know that chose48-63of them can reveal the genetic polymorphism among different germplasm resources. After chose60of them, clustering analysis result is similar to the result for134SSR molecular markers, and it can reveal the genetic polymorphism sufficiently.