Having reviewed the major classification systems proposed by various scholars across the world, it is found that \%indica\% and \%japonica\% under \%O.sativa\% L. are two major directions thoroughly differentiated fro...Having reviewed the major classification systems proposed by various scholars across the world, it is found that \%indica\% and \%japonica\% under \%O.sativa\% L. are two major directions thoroughly differentiated from the Asian cultivated rice, forming the framework of the classification structure. A system with \%indica\% and \%japonica\% as the only two subspecies is therefore reiterated.There are various ways to determine the indica_japonica identity of hybrid rice, but the "combined morphological trait index"(CMT index) method is more efficient and easier to handle, although the isozyme analysis, molecular marker analysis and grain quality assay methods are also feasible.展开更多
DNA polymorphisms from nucleotide insertion/deletions(InDels)in genomic sequences are the basis for developing InDel molecular markers.To validate the InDel primer pairs on the basis of the comparative genomic study o...DNA polymorphisms from nucleotide insertion/deletions(InDels)in genomic sequences are the basis for developing InDel molecular markers.To validate the InDel primer pairs on the basis of the comparative genomic study on DNA sequences between an Indica rice 93-11 and a Japonica rice Nipponbare for identifying Indica and Japonica rice varieties and studying wild Oryza species,we studied 49 Indica,43 Japonica,and 24 wild rice accessions collected from ten Asian countries using 45 InDel primer pairs.Results indicated that of the 45 InDel primer pairs,41 can accurately identify Indica and Japonica rice varieties with a reliability of over 80%.The scatter plotting data of the principal compo-nent analysis(PCA)indicated that:(i)the InDel primer pairs can easily distinguish Indica from Japonica rice varieties,in addition to revealing their genetic differentiation;(ii)the AA-genome wild rice species showed a relatively close genetic relationship with the Indica rice varieties;and(iii)the non-AA genome wild rice species did not show evident differentiation into the Indica and Japonica types.It is con-cluded from the study that most of the InDel primer pairs obtained from DNA sequences of 93-11 and Nipponbare can be used for identifying Indica and Japonica rice varieties,and for studying genetic relationships of wild rice species,particularly in terms of the Indica-Japonica differentiation.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
基金This research were supported by the Asia Rice Biotechnology Net Work project -Achieving Impact and Sus-tainabilitysponsored by Asian Development Bank. And the International cooperation project-studies on the resistance gene withmolecular biotechnologysupported by the Guangdong Province Commission of Science and Technology of China and Guangdong A-cademy of Agricultural Sciences.
文摘Having reviewed the major classification systems proposed by various scholars across the world, it is found that \%indica\% and \%japonica\% under \%O.sativa\% L. are two major directions thoroughly differentiated from the Asian cultivated rice, forming the framework of the classification structure. A system with \%indica\% and \%japonica\% as the only two subspecies is therefore reiterated.There are various ways to determine the indica_japonica identity of hybrid rice, but the "combined morphological trait index"(CMT index) method is more efficient and easier to handle, although the isozyme analysis, molecular marker analysis and grain quality assay methods are also feasible.
基金This study was supported by the Italian Ministry of Environment and Environmental Protection,within the research project Application of biotechnology to the protection of the environment in collaboration with China.
文摘DNA polymorphisms from nucleotide insertion/deletions(InDels)in genomic sequences are the basis for developing InDel molecular markers.To validate the InDel primer pairs on the basis of the comparative genomic study on DNA sequences between an Indica rice 93-11 and a Japonica rice Nipponbare for identifying Indica and Japonica rice varieties and studying wild Oryza species,we studied 49 Indica,43 Japonica,and 24 wild rice accessions collected from ten Asian countries using 45 InDel primer pairs.Results indicated that of the 45 InDel primer pairs,41 can accurately identify Indica and Japonica rice varieties with a reliability of over 80%.The scatter plotting data of the principal compo-nent analysis(PCA)indicated that:(i)the InDel primer pairs can easily distinguish Indica from Japonica rice varieties,in addition to revealing their genetic differentiation;(ii)the AA-genome wild rice species showed a relatively close genetic relationship with the Indica rice varieties;and(iii)the non-AA genome wild rice species did not show evident differentiation into the Indica and Japonica types.It is con-cluded from the study that most of the InDel primer pairs obtained from DNA sequences of 93-11 and Nipponbare can be used for identifying Indica and Japonica rice varieties,and for studying genetic relationships of wild rice species,particularly in terms of the Indica-Japonica differentiation.
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.
