Genetic Diversity Analysis Of Early Japonica Rice Germplasm In Ningxia And Northeast Reigon Of China

Rice is one of the main grain crops in Ningxia. Because of the important influence of germplasm resources on rice breeding, study genetic diversity of rice to clarify the genetic relationship between rice cultivars in Ningxia and in Northeast China is particularly important for utilizing these rice permplasm resources and rice breeding. The paper analyzed phenotypic genetic diversity of 113 rice germplasm resources in Ningxia and 132 germplasm resources in Northeast China and analyzed genetic diversity by SSR molecular markers. The main results were as follows:1. By analyzing the correlation between 13 phenotypes of 245 accessions in Ningxia and in Northeast China, the results showed that there were significant or extremely significant correlations among different phenotypic traits. Some traits such as plant height and grain length were positively correlated with the number of grains per panicle, but Some traits such as grain width and the two branches are negative correlation, and different traits have very complicated relationship.2.By analyzing phenotype traits genetic diversity of 245 germplasm resources in Ningxia and in Northeast China, the results showed that the rarage of genetic diversity index of 13 personality traits was from 1.5 to 2.09.The smallest of the genetic diversity index is grain aspect ratio at 1.5and the maximum genetic diversity index is once branch at 2.09. Besides phenotypic traits diversity index of the seed setting rate, aspect ratio of grain,panicles per plant, others were below 2.0,other nine phenotypic traits of genetic diversity index were at 2～2.09, that was very small range and showed that the phenotype traits genetic diversity index of 245 germplasm resources in Ningxia and in Northeast China changed littlly,genetic diversity was not high.3.Using different phenotypic traits for germplasm clustering analysis,average distance was equal to 1.5 as threshold.245 rice germplasm in Ningxia and Northeast China was classed into two categories,The first category contains 237 germplasm resources and there distributed in Ningxia, Heilongjiang, Jilin, Liaoning;the second category was all Ningxia local rice.It was indicated the rice germplasm of Ningxia and Northeast China had near relationship and the genetic basis was narrow.4.According to the results of SSR molecular markers,the result showed that 36 pairs of SSR primers detected 151 alleles at each locus 2-8and the average was 4.19.Wherein Ningxialandrance germplasm was detected 126 alleles and an average was 3.50. Northeast germplasm detected 139 alleles, and the average of 3.86. The alleles numbers of the northeast germplasm resources was more than that of Ningxia.5. Comparative analysis on genetic diversity of SSR in Ningxia and Northeast China showed that the diversity index of rice resources in Ningxia was 0.3380, the Northeast was 0.5657, and the overall diversity index was 0.5896, which showed that the genetic diversity of Ningxia germplasm resources was lower than that rice of the northeast China, but overall diversity was very low. The clustering analysis of 245 SSR molecular marker showed that Ningxia recounts and northeast source were not separated, and the majority of poly together. There results that Ningxia rice materials and Heilongjiang, Jilin and Liaoning rice material had a close genetic relationship was further confirmed.