Genetic Diversity Analysis Of Landraces And Self-fertile Cultivares Of Rice In Ningxia

In this study,145rice germplasm resources in Ningxia were used for the tested materials, of which 13 land races and 132 self-fertile cultivars.Used phenotypic traits and SSR molecular markers to analyzed the genetic diversity of the test materials,and the results showed that:1.Except for first panicle branch, the difference of genetic variation between the plant height,spike length,seed setting rate,1000-grain weight and other 19quantitative traits were extremely significant showed that there is a big genetic difference among rice germplasm resources of Ningxia.The performance of shell color, glume tips color, grain shape and so on four quality traits relatively concentrated,and the genetic difference was small.Using principal components analysis to analyze the nineteen traits which showed very significant difference, eight large eigenvectors were chosen from nineteen characteristic root, respectively are total grains per panicle, total grains weight per plant,tillering number per plant, ratio of grain length to width, plant height, flagleaf width,seed setting rate and 1000-grain weight, which can be used as the main factor, and their cumulative rate was 88%.2.while the Shannon genetic diversity indices of 20 quantitative traits of rice germplasm resources in Ningxia ranged from,0.24 to 2.11,the diversity indices of the most quantitative traits were ranged front 1.5-2.0, show the differences of rice germplasm resources in ningxia were not big on the whole. The Shannon genetic diversity indices of 13 landraces ranged from 0.24-1.99,the average genetic diversity index wasl.34,Show that genetic differences among landraces relatively large, favorable genes can be found. The Shannon genetic diversity indices of 132 self-fertile cultivars ranged from 1.20to2.11,the average genetic diversity index wasl.83b amplitude is relatively small, which indicates that small genetic differences between self-fertile cultivars.3.Used the UPGMA method, all the 145 rice varieties could be divided into five groups when similarity coefficient was 0.9,the group I and group Ⅱ contained only one variety each,they were Ningda 15147 and Ningda 143,group III contained 29 high-yield varieties,group Ⅳ contained 93 varieties which account for 64% of total 145 varieties,bred in recent years,showed that most self-fertile cultivars had a nearer relationship.Group V contained the most of landraces, showed that there is a big difference between self-fertile cultivars and landraces.4.Used 65 pairs of SSR primers to analyze genotype polymorphism of 145 rice germplasm resources in ningxia.A total of 271 alleles were detected,the number of alleles variation range was 3-7, with an average of 4.1385,the number of effective alleles ranged from 1.0001-4.7647 to 2.6597,with an average of,the Shannon index is in the range of 0.2449-1.8892, with an average of 1.2150,Nei’s gene diversity index was between 0.2751-0.7467, with an average of 0.5516,each site Nei’s genetic diversity index of the order and Shannon index is basically the same,genetic diversity of rice germplasm resources in Ningxia was small, and the polymorphism was rare.According to the genotype data clustering analysis was carried out on the 145 rice germplasm resources by UPGMA method,the genetic similarity coefficient reached 0.69can be divided into 4 group,group I contained 5varieties,all scented rice varieties were gathered in this group.Group Ⅱ and group Ⅲ each contain 4 varieties, indicated that the genetic distance of 8 varieties and other varieties of the far,Other 132 rice germplasm resources were gathered in the group ￥,Yanghebaipidao, Yeshengbaipidadao and other landraces were gathered together,the genetic diversity is small of rice germplasm resources in Ningxia.The analysis of population genetic structure showed that rice germplasm resources in Ningxia had a close genetic relationship, genetic basis is relatively narrow, caused the small differences between the varieties.5.Compared the genetic diversity among landraces and self-fertile cultivars,the result showed that self-fertile cultivars with higher genetic difference than landraces,the self-fertile cultivars produce more polymorphism.Through the analysis of SSR markers in different chromosomes of landraces and self-fertile cultivars on some diversity parameters,the self-fertile cultivars of Nei’s gene diversity index and Shannon diversity index is higher than landraces. The number of alleles in chromosome of landraces is more than self-fertile cultivars or the same as self-fertile cultivars,indicate that there were more favorable genes in landraces.But by comparing every Shannon index of SSR markers found that on chromosomes found that genetic diversity index of polymorphism markers in chromosomes land 3were higher than self-fertile cultivars,showed that polymorphism is not on the whole genome, but at a certain site, or on a section of the chromosome.used Nei unbiased genetic distance build Neighor joining clustering,,analyze the relationship between landraces and self-fertile cultivars showed that there is a close genetic relationship between the landraces and the early year bred cultivars, the agriculture close genetic relationship between bred varieties of agriculture,and there is a close genetic relationship among self-fertile cultivars.