caa a22 4500 477133479 CHVBK 20180405111710.0 cr unu---uuuuu 170330e19970301xx s 000 0 eng 10.1023/A:1002907421839 doi (NATIONALLICENCE)springer-10.1023/A:1002907421839 Identification of two types of differentiation in cultivated rice (Oryza sativa L.) detected by polymorphism of isozymes and hybrid sterility [Elektronische Daten] [Jianmin Wan, Hiroshi Ikehashi] Magnitudes of genetic variation within each of major varietal groups of cultivated rice were surveyed in terms of isozyme polymorphism and allelic differentiation of hybrid sterility loci, both of which are considered to have litt le selective value. Allelic differences for 20 isozyme loci were examined in a total of 337 accessions, including Indica and Japonica rices. Aus cultivars from India, Javanica cultivars and both landraces and cultivars from China. Eleven out of the 20 isozyme loci were polymorphic. The Aus cultivars contained more alleles per locus than others. The hybrid sterilities in the crosses among Chinese cultivars, Indica and Japonica cultivars were mainly controlled by locus S-5, whereas the hybrid sterilities of Aus cultivars, when they were crossed to Indica, Japonica or Javanica cultivars, were found to be controlled by allelic interaction at hybrid sterility loci S-5, S-7, S-9 and S-15. Also in terms of the number of alleles at S-5 and S-7, Aus cultivars contained more alleles than others. While the Aus group showed an extreme diversity for both hybrid sterility alleles and isozymes, modern cultivars from the south of YangZi River in China were classified into Indica type and those from the north were into Japonica, which were almost the same as those in Japan. On the basis of the measured polymorphism the Indica-Japonica differentiation was explained by founder effects, i.e., through selection and distribution of two original sources each with a unique set of markers. Contrastingly, the continuous and pronounced diversity in the Aus group was attributed to the absence of such a process. The intermediate groups in Yunnan province and Tai-hu Lake region of China are considered to be isolated from such founder effects, retaining an intermediate diversity in terms of isozymes and hybrid sterility genes. Since hybrid sterility hampers the exchange of genes between cultivars of different groups, the understanding of its genetic basis will be important in rice breeding, particularly in hybrid rice breeding. Kluwer Academic Publishers, 1997 Oryza sativa nationallicence Aus nationallicence rice nationallicence hybrid sterility nationallicence isozomes nationallicence varietal diversity nationallicence Wan Jianmin Nanjing Agriculture University, 210095, Nanjing, China aut Ikehashi Hiroshi Faculty of Agriculture, Kyoto University, 606-1, Kyoto, Japan aut Euphytica Kluwer Academic Publishers 94/2(1997-03-01), 151-161 0014-2336 94:2<151 1997 94 10681 https://doi.org/10.1023/A:1002907421839 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1002907421839 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wan Jianmin Nanjing Agriculture University, 210095, Nanjing, China aut NATIONALLICENCE 700 1- Ikehashi Hiroshi Faculty of Agriculture, Kyoto University, 606-1, Kyoto, Japan aut NATIONALLICENCE 773 0- Euphytica Kluwer Academic Publishers 94/2(1997-03-01), 151-161 0014-2336 94:2<151 1997 94 10681 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer