Analysis Of Genetic Diversity And Construction Of Molecular ID In Peanut Varieties In China

Peanut is an important oil crops, cash crops and export of agricultural products inChina. In recent years, the number of new peanut varieties increased sharply, while thehigh-frequency of usage of a small number of the backbone cultivars lead to thenarrow genetic base. Thereby, it seems so difficult to distinguish different peanutvarieties by phenotypic traits. Construction of molecular ID database of peanutvarieties will play important roles in identifying the authenticity and purity, certifyingvariety and quality. The analysis of genetic diversity was significance for improvingvarieties, cultivate new varieties, innovating and using of superior germplasmresources.In this study, firstly, in order to screen a fast and easy method of extracting DNAfor the SSR analysis, four different DNA extraction methods were optimized. SSRmarkers and AhTE markers were used to analyze the genetic diversity of219peanutvarieties..It is the first time that ID analysis software is used to build molecular ID forpeanut varieties. The main results were as follows:(1) By comparing and optimizing four different DNA extraction methods: theHigh-throughput DNA extraction method, the simple SDS method, TPS method andTENP method, the improved TPS method was better than the other three methods. Itcan be used for SSR analysis in peanut.(2) Forty five pairs of SSR primers and Thirty one pairs of AhTE primers wereused to amplify219peanut varieties. All primers showed the polymorphism amongpeanut varieties tested, and AhTE primers showed the higher polymorphism than SSRprimers. One hundred and thirty-one alleles were detected by forty-five polymorphic SSR primer pairs. The average number of alleles per SSR primer was3, and thehighest PIC was0.783. Seventy-five bands were amplified by thirty-one polymorphicAhTE primer pairs. The average number of bands per locus was2.4, and the highestPIC was1.268.(3) Cluster analysis with NTSYS showed that genetic similarity coefficient (GS)varied between0.59and0.96. At GS of0.634, the all peanuts could be divided into sixgroups. Some peanuts had the higher GS, so they had the closed genetic relationship.The219peanut varieties didn’t show the obvious geographical feature from thedendrogram.(4) The mean value of specialty index was123.288, between83.437and402.578.Thirty four pairs of SSR primers were chosen to build molecules ID for163peanutvarieties, while got two varieties with specific alleles. It could be use of identifying thespecies by the specific alleles directly. Fifteen pairs of AhTE primers were chose tobuild molecules ID for210peanut varieties, which had26polymorphic loci.