Study On Genetic Diversity And Establishment Of Pre-core Collection Of Common Wild Rice (Oryza Rufipogon Griff.) In Northern Of Guangdong

Common wild rice (Oryza rufipogon Griff.) widely distributes in China. As ancestor of cultivar rice, the commom wild rice is one of the most important and valuable germplasm resources. northern of Guangdong is main reign for the distribution of commom wild rice in Guangdong province, and therefor, has the unique status of rice resources in our country. In order to provide theoretic and practical evidences for protection and evaluation of commom wild rice, also the utilization in cultivar rice, genetic diversity, indica-japonica differentiation and establishment of core collection were analyzed by using 174 individuals in 5 population groups of commom wild rice in Northern of Guangdong. The main results of the study were presented as followings:1. Analysis of 21 morphological characters for 174 individuals indicated that the morphological diversity of commom wild rice in Northern of Guangdong. was abundant. The average diversity index was 1.178. Genetic diversity was analyzed using 48 pairs of SSR primers. All of the 48 SSR markers showed polymorphism and a total of 491 alleles were detected. The number of average alleles per locus(A) was 10.23, the effective number of alleles (Ae) was 5.13, and total genetic diversity was 0.7562. Relatively high level of genetic variation was detected both at species and population levels. The cofficient of gene differentiation suggested that most variation happened among the individuals within populations, only 5.78% genentic variation existed among populations.2. One hundred and seventy-four individuals of common wild rice in Northern of Guangdong. were analyzed by using 28 pairs of SSR primers which could differentiate indica and japonica types of cultivated rice. All of 28 pairs of primers showed polymorphism among 174 individuals. In addition to the alleles specific for indica and japonica type, the unique alleles for the common wild rice could also be amplified. Clustering analysis of genetic identity revealed that there was elementary indica-japonica differentiation among common wild rice of Northern of Guangdong. 2 individuals(1.15%)were more in indica-type,172 individuals(98.85%)were more in japonica-type, the population were mainly japonica-type, indicating elementary indica-japonica differentiation amony common wild rice of Northern of Guangdong.3. One hundred and seventy-four individuals of common wild rice in Northern of Guangdong. was clustered based on 21 morphological characters and core collection was seclected using system cluster sampling of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%. Ratio of phenotype retained, Shannon-Weaver Index, coefficient of variation and variance of phenotype were used to compare representativeness of the 9 core collection with different sampling proportion. The results showed that 50% sampling proportion got good representation of total resource. By representative test, the result showed that the pre-core collection can effectively represent the whole collection of common wild rice in Northern of Guangdong.