To understand geographical distribution of the genetic diversity of rice cultivars {Oryza sativa L.) and its trends in recent fifty years in China, 453 ’ accessions were analyzed by 36 microsatellites loci and 42 phe...To understand geographical distribution of the genetic diversity of rice cultivars {Oryza sativa L.) and its trends in recent fifty years in China, 453 ’ accessions were analyzed by 36 microsatellites loci and 42 phenotypic traits. Results revealed that the genetic diversity by SSRs is highly consistent with that by phenotypic traits and the genetic diversity of indica cultivars was higher than that of japonica cultivars; the genetic diversity of cultivars declined from 1950s to 1980s and then increased greatly; among the six rice ecological zones (REZs), genetic diversity of REZTl was the highest and those of REZV and REZVT were the lowest at both DNA and phenotypic level. Jiangsu and Jiangxi provinces in the middle and lower reaches of Yangtze River and Sichuan province in southwest of China were the areas with the highest genetic diversity. Breeders in REZV which is an important japonica rice area but with very low genetic diversity should explore more gene resources to widen the genetic backgrounds of cultivars.展开更多
Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic ...Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic diversity and structure of 537 accessions of cultivated rice from Guizhou were studied using 36 microsatellite markers and 39 phenotypic characters. The results showed that the model-based genetic structure was the same as genetic-distance-based one using SSRs but somewhat different from the documented classification (mainly based on phenotype) of two subspecies. The accessions being classified into indica by phenotype but japonica by genetic structure were much more than that being classified into japonica by phenotype but indica by genetic structure. Like Ding Ying’s taxonomic sys- tem of cultivated rice, the subspecific differentiation was the most distinct differentiation within culti- vated rice. But the differentiation within indica or japonica population was different: japonica presented clearer differentiation between soil-watery ecotypes than indica, and indica presented clearer differen- tiation between seasonal ecotypes than japonica. Cultivated rices in Guizhou revealed high genetic diversity at both DNA and phenotypic levels. Possessing the highest genetic diversity and all the nec- essary conditions as a center of genetic diversity, region Southwestern of Guizhou was suggested as the center of genetic diversity of O. sativa L. from Guizhou.展开更多
文摘To understand geographical distribution of the genetic diversity of rice cultivars {Oryza sativa L.) and its trends in recent fifty years in China, 453 ’ accessions were analyzed by 36 microsatellites loci and 42 phenotypic traits. Results revealed that the genetic diversity by SSRs is highly consistent with that by phenotypic traits and the genetic diversity of indica cultivars was higher than that of japonica cultivars; the genetic diversity of cultivars declined from 1950s to 1980s and then increased greatly; among the six rice ecological zones (REZs), genetic diversity of REZTl was the highest and those of REZV and REZVT were the lowest at both DNA and phenotypic level. Jiangsu and Jiangxi provinces in the middle and lower reaches of Yangtze River and Sichuan province in southwest of China were the areas with the highest genetic diversity. Breeders in REZV which is an important japonica rice area but with very low genetic diversity should explore more gene resources to widen the genetic backgrounds of cultivars.
基金the National Basic Research Program of China ("973" Program) (Grant No. 2004CB117201)the Key Technologies R&D Programme of China (Grant No. 2004BA525B02-05)
文摘Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic diversity and structure of 537 accessions of cultivated rice from Guizhou were studied using 36 microsatellite markers and 39 phenotypic characters. The results showed that the model-based genetic structure was the same as genetic-distance-based one using SSRs but somewhat different from the documented classification (mainly based on phenotype) of two subspecies. The accessions being classified into indica by phenotype but japonica by genetic structure were much more than that being classified into japonica by phenotype but indica by genetic structure. Like Ding Ying’s taxonomic sys- tem of cultivated rice, the subspecific differentiation was the most distinct differentiation within culti- vated rice. But the differentiation within indica or japonica population was different: japonica presented clearer differentiation between soil-watery ecotypes than indica, and indica presented clearer differen- tiation between seasonal ecotypes than japonica. Cultivated rices in Guizhou revealed high genetic diversity at both DNA and phenotypic levels. Possessing the highest genetic diversity and all the nec- essary conditions as a center of genetic diversity, region Southwestern of Guizhou was suggested as the center of genetic diversity of O. sativa L. from Guizhou.
