Analysis of Genetic Diversity with Population of Japonica Rice from Ningxia Using Microsatellite Markers

A total of 82 SSR markers distributed on 12 chromosomes were used to analyze genetic diversity and genetic similarity in 59 rice varieties of Ningxia province after 1980s. 339 alleles were revealed,and 2 to 19 alleles were identified among different loci. The mean number of alleles per locus was 4. 13. Total Nei' s genetic diversity index varied greatly from 0. 0333 to 0. 9164,with an average of 0. 4394. The 55 rice varieties were divided into 3groups according to their released years. With the increase of the year,both the number of alleles and genetic diversity showed an significant increasing trend( P 0. 01). UPGMA cluster analysis showed that the 59 rice varieties were cluster into five categories at the genetic similarity coefficient of 0. 78. The category Ⅰ had only one aromatic rice,Ⅱ and Ⅳ both had three varieties,and category Ⅲ contained five varieties similar to Jilin rice. The most rice varieties were clustered into category Ⅴ,which accounted for 79. 7% of the tested varieties. Compared the pedigree of rice varieties,the vast major varieties had kinship of Ningxia core parental such as Hongqi 12,Jingyin 39,Dongfanghong 2,Jingyin 59,etc,which showed close relationship among varieties. Although the genetic diversity of Ningxia rice had increased in recent years,the genetic basis was still narrow. The similarity coefficient of the tested varieties was above 0. 70,even as high as 0. 97. Breeders must introduce and innovate more parental materials in order to expand the genetic foundation of Ningxia rice in the future.