Study On Indica-japonica Differentiation And Establishment Of Core Collection Of Common Wild Rice (Oryza Rufipogon Griff.) In Gaozhou Of Guangdong Province

Two hundred and seventen materials of common wild rice (O. rufipogon Griff.) in Gaozhou which were from 7 different populations were regarded as the object in the paper. Indica-japonica differentiation condition was researched, phenotypic diversity was analysised and core collection was established based on phenotype and molecular level. Main results were as followings:1. The micro core collection of cultivated rice in China was used as control, and used 32 pairs of SSR primers which could distinguish Indica and Japonica were used for wild rice in Gaozhou. The results showed that indica-like type, japonica-like type and original type coexist in these wild rice populations. But compared with the cultivated rice, the indica-japonica differentiation was more elementary. The population which original on genetic structure were trends of Japonica-like type on genetic distance. Therefore, common wild rice in Gaozhou plays a significant role in origin and evolution and genetic differentiation of asian cultivated rice, and it was valuable in gene discovery and breeding practice.2. Twenty two phenotypic characters were investigated and the phenotypic variation has been analyzed. SPSS and DPS softwares were used for correlation analysis, cluster analysis and variance analysis. There were plentiful phenotypic variation and extremely significant correlation among many characters in Oryza rufipogon in Gaozhou. The phenotypic characters have significant difference among the 7 groups determined by clustering. Though the populations were similar among them, to some extent it was also diverse from each other. There exist some rules in phenotypic variation of Oryza rufipogon in Gaozhou. Because of the profuse phenotypic diversity and independence of Oryza rufipogon in Gaozhou, it is necessary to selected some representative materials for further study and application.3. Based on the phenotypic and molecular marker data and using system cluster sampling, the suitable selecting scale was determined by multiple comparison. The core collection have been established based on phenotypes (43 materials which 20% of total resources) and molecular markers (24 materials which 10% of total resources). Ratio of phenotype retained, Variance of phenotype, Shanno-Wavear Index, Coefficient of variation, ratio of allele retained, Simpson Index. were used to examine representativeness of the core collection. The results showed that the core collection got good representation of total resource. Ratio of phenotype retained achieved 98.86%, ratio of allele retained was 90%, and other parameters also showed that the core collection, to a great extent, has eliminated genetic redundancy of total resources, and met the requirement of core collection. This study has laid a good foundation for effective preservation, further study and utilization of wild rice in Gaozhou.