携有不同主效白叶枯病抗性单基因的3个粳稻近等基因系的选育

自１９８６至１９９３年，我们选育了第一批携有抗水稻白叶枯病主效基因，Ｘａ－３、Ｘａ－４和Ｘａ－１２的３个粳稻近等基因系：ＣＢＢ３、ＣＢＢ４和ＣＢＢ１２（暂名）。以１个感病并具有改良株型的粳稻品种沈农１０３３为轮回亲本，通过回交、自交直至ＢＣ５Ｆ５代。各世代经抗性测定和株型选择，直至各系的抗性稳定和农艺性状趋于一致。进行了３个近等基因系与其供体基因的抗性反应型比较、农艺性状考查及抗性遗传分析。通过育

Breeding of Three Near-isogenic Japonica Rice Lines with Different Major Genes for Resistance to Bacterial Blight

A set of near-isogenic japonica rice lines with different major genes, Xa-3, Xa-4 and Xa-12 for resistance to Bacterial blight were developed and designated as CBB3, CBB4 and CBB12 from 1986 to 1993. A japonica cultivar with improved plant type, Shennong 1033, which is highly susceptible to bacterial blight was selected as recurrent parent in the study. The progenies possessing each one of the genes. Xa-3, Xa-4 and Xa-12 were developed by backcross-ing, selfing until B5F5 generation. Evaluation of resistance to bacterial blight and selection of plant type being successively till obtaining the lines with stable resistance and common agronomic characters. Comparison of reactoin for resistance to bacterial blight between the near-isogenic lines and their donors was made. Genetic analysis of resistance to Bacterial blight and investigation of agronomic characters were made. The three lines are valuable in rice breeding and biotechnology studies.