Genetic Diversity Studies On Primary Core Collection Of Landrace Rice Resources In Yunnan, China

ABSTRACTThis dissertation studied the genetic diversity of subspecies , 17 administriction districts and 5 ecological zones with the primary core collection of 912 Yunnan landrace rice .Firstly, genetic diversity of primary core collection was studied at six isozymes( 12 isozyme loci). The results showed that : Average genetic diversity of Japonica was higher than that of Indica and their genetic differentiation was not remarkable; In subspecies, Average genetic diversity of Upland rice was higher than Paddy rice and their genetic differentiation in Indica was higher than that of in Japonica; Average genetic diversity of several administriction districts in west-south Yunnan was higher than that of other district; In five ecological zones, Average gene diversity of Zone of paddy and upland rice in south edge of Yunnan was highest, Genetic differentiation among five ecological zones was low.Secondly, genetic diversity at DNA level was studied with 107 representative accessions of landrace rice in Yunnan and 20 rice SSR primers allocating on 12 chromosomes of rice respectively. The result showed that : Average genetic diversity of Japonica was higher than Indica and their index of genetic differentiation was lower than that at isozyme level; Average gene diversity of Zone of paddy and upland rice in south edge of Yunnan was highest in five ecological zones. Genetic differentiation among five ecological zones was much higher than isozyme level.Thirdly, Combining results of the genetic diversity and differentiation studies of morphologic characters and isozyme loci, SSR primary data, analysed their correlation at phenotype, isozyme and DNA level briefly. Results showed that diversity of rice resources presented at phenotype, isozyme and DNA levels was accordant, non-synchro genetic variation was also revealed.