杂交稻抗白叶枯病的遗传机制

8种不同胞质类型的不育系及其保持系与9个恢复系按P×Q交配设计分别配制不育系杂种和保持系杂种， 接种白叶枯病(Xoo)“强”致病力菌系ZHE-173和“弱”致病力菌系KS-6-6， 研究杂交稻抗白叶枯病的遗传机制。 结果表明： (1) 不育系或保持系、 恢复系以及不育系或保持系与恢复系间的互作对不育系杂种或保持系杂种抗性的影响均

Genetic Mechanism of Resistance to Bacterial blight (Xanthomonas oryzae pv. oryzae) in Hybrid Rice

Eight different cytoplasmic male sterile lines and their corresponding maintainer lines were crossed with nine restoring lines harbouring dominant R-genes Xa-3, Xa-4, Xa-7 and Xa-21 respectively according to P x Q design. Male sterile line hybrids and maintainer line hybrids were inoculated with strong and weak virulent Xoo strains ZHE-173 and KS-6-6 for purpose of probing into genetic mechanism of resistance. The results showed that: (1) male sterile lines or their corresponding maintainer lines, restoring lines, and interaction between male sterile lines or their corresponding maintainer lines and restoring lines were high significantly effect resistance of male sterile line hybrid and their corresponding maintainer line hybrid. (2) resistance of hybrid rice was significantly or high significantly correlated with male sterile lines, maintainer lines, restoring lines, and mid-parents value. (3) resistance heterosis of rice were affected by type of parents of combination. They existed positive or negative incomplete dominance and overdominance, but they were mainly positive dominance. (4) resistance to Xoo in hybrid rice was controlled by nuclear genes, not by cytoplasmic genes, similar to conventional breeding cultivars. We suggested that the key to increase resistance level and resistance durability of hybrid rice is to transfer dominant or recessive major genes with better resistance, wider resistance spectra, and better stability of resistance performance in crosses and pyramid minor genes into restoring lines, male sterile lines and maintainer lines.