| The primary core collection of Chinese landrace rice (Oryza sativa L.)including 3632 accessions was studied by using 36 microsatellite primers. Firstly, the genetic diversity and differentiation of Dingying's taxonomic system was studied. Secondly, the distribution of the genetic diversity among different ecological zones, different ecological subzones, different provinces was studied. Thirdly, The cluster method was probed by using the morphological data and SSR data from primary core collection to core collection. The results is followed.The number of alleles and the genetic diversity of indica was higher than those of japonica at DNA level and the genetic diversity and the differentiation distribution was uneven among different SSR loci and chromosomes. It is the same in each ecological zone, subzone and province. For Dingying's taxonomic system, the average genetic diversity of glutinous rice and nonglutinous rice was higher than that of paddy rice and upland rice, and the latter is higher than that of indica and japonica. But the coefficient of genetic differentiation was the other way round. It revealed that differentiation was the highest between indica and japonica.The genetic diversity descended from southern to northern geographically. South China and central China were the highest than the other ecological zones at genetic diversity of SSR level. Yunnan province was the centre of genetic diversity of landrace rice. Guizhou province was the centre of genetic diversity of indica and Hainan province was the centre of genetic diversity of japonica. The study of cluster method for core collection indicated that the core collection had higher genetic diversity when clustered simultaneously by morphological data and SSR data and the limitation could be overcome when clustered simply by morphological data or by SSR data. Comparing the different sampling proportion, the core collection of sampling proportion 50% with higher CV, VAR and RPR was the best than others. |
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