籼稻品种三黄占2号的稻瘟病持久抗性评价与遗传分析

 籼稻三黄占2号在生产上种植10多年,表现了稳定持久的稻瘟病抗性。接种及多点田间试验结果表明,三黄占2号不仅对中国稻瘟病菌株有广谱抗性,而且对菲律宾稻瘟病菌株亦有高的抗性频率(98%)。在国际稻瘟病圃(IRBN)其叶瘟及穗瘟抗性相当或好于持久抗性品种OS6、Moroberekan和IR36。三黄占2号感病后,亦显示出高水平稻瘟病数量抗性。分析由三黄占2号与丽江新团黑谷杂交构建的重组自交系分离群体的抗病性,发现三黄占2号稻瘟病质量抗性是由多个主效基因控制的,其稻瘟病数量抗性是非小种专一的。应用候选抗性基因方法鉴

Genetic Analysis and Evaluation of Durable Resistance to Blast in Indica Cultivar Sanhuangzhan2

Sanhuangzhan 2 (SHZ-2), an indica cultivar, has been planted in South China for more than 10 years andshowed durable resistance to blast. Inoculation and multi-locational tests indicated that SHZ-2 not only had a broadspectrum of resistance to the Chinese blast isolates, but also had a high frequency of resistance to the Philippine isolates(98%), and its leaf blast and neck blast resistance in International Rice Blast Nurseries (IRBN) were as good as or even betterthan OS6,Moroberekan and IR36 which were recognized as cultivars with durable resistance to blast. High level of quantitativeresistance to blast in SHZ-2 was also recorded after it was infected by compatible isolates. The results from analysis ofdisease resistance in recombinant inbred lines derived from cross between SHZ-2 and Lijiangxintuanheigu(LTH) in differentinoculation and field tests suggested that the blast qualitative resistance in SHZ-2 was controlled by multiple major genes,and its blast quantitative resistance was race-non specific. With candidate resistance gene approach, three major genesassociated with blast qualitative resistance and five defense response gene markers significantly associated with blastquantitative resistance in SHZ-2 were identified. Research results suggest that the both combination of broad spectrum ofblast qualitative resistance and high level of blast quantitative resistance in SHZ-2 contributes to its durable blast resistance.Advanced backcrossed and molecular-assisted selection was performed to introduce the blast resistance genes from SHZ-2 into Texianzhan 13(TXZ-13), an indica type cultivar with high yielding and good quality but susceptible to blast. Severalnew resistance lines bearing several major genes and QTLs were obtained.