籼型杂交水稻及三系对白叶枯病的抗性预测

FORECASTING OF RESISTANCE TO BACTERIAL BLIGHT IN HYBRID RICE AND THEIR PARENTS

】比较了水稻三系的抗性及其对杂交稻抗性的贡献。结果表明，杂交稻的抗性主要受恢复系的核基因控制，同时也受不育系胞质效应的影响。Ｄ型、冈型和野败型胞质的抗性较差，滇型和ＢＴ型较强。由于不同稻区的病菌小种组成不同，致病力的亲和性以及分化变异速度也不同，故推广杂交稻组合应考虑病菌小种的组成和分化趋势。

Bacterial blight, which decreased severely the yield on indica type hybrid rice and wild type of cytoplasmic male sterize (W type CMS) was wide distributed in China rice area and occupied about 75% of hybrid rice area. Compared the resistance to bacterial blight in CMS lines(A) , mantainer lines(B) and restorer lines(C), the contribution of resistance in 3 lines to the hybrid rice(F 1) were estimated. The resistance is controlled mainly by restorer resistant genes, but the CMS line also play an important role. The resistance to X.oo in hybrid rice correlated with mid parent value and more or less biased toward resistant parent. Wide type, Gambiaka type, and Dissi type CMS were more susceptible than T type and BT type. The predominant races of pathogenic bacteria must be predisposed with before the combinations of hybrid rice to be released.