三份重要水稻资源的稻瘟病抗性鉴定及不同评价指标间的相关性分析

为明确杂交水稻育种骨干亲本93-11、纹枯病重要抗源YSBR1及水稻重要基础研究的遗传转化材料Kitaake共3份重要水稻资源的稻瘟病抗谱及不同评价指标间的相关性，通过喷雾接种法，采用国际水稻稻瘟病抗性评价分级标准、致病率、病斑数量和病斑长度4个评价指标，分析了这3份重要水稻资源对36个稻瘟病菌生理小种的抗性。结果表明这3份水稻资源材料的病情指数主要集中于4和5级，但针对不同的生理小种其致病率存在较大差异。同时，93-11、YSBR1和Kitaake产生的病斑平均长度分别为0.56、0.54和0.66 cm，病斑平均数量分别为6.50、4.10和4.80个。Spearman相关性分析证明所采用的4个稻瘟病抗性评价指标之间均呈极显著正相关。表明93-11、YSBR1和Kitaake均对多数稻瘟病生理小种表现出抗性，但抗谱各不相同，且采用的4个评价指标间无显著差异。

Evaluation of the resistance spectrum of three important rice cultivars against blast disease caused by Magnaporthe oryzae and correlation analysis among evaluation indexes

To determine the resistance spectrum of three important rice cultivars (93-11, one of the backbone parents of hybrid rice, YSBR1, an important genetic resource with high resistance to sheath blight, and Kitaake, an important resource for genetic transformation) and correlation among evaluation indexes, their blast resistance were evaluated using four evaluation indexes (the international evaluation classification standard of rice blast resistance, pathogenicity frequency, lesion number and lesion length). The inoculation method was spray inoculation with 36 isolates of Magnaporthe oryzae collected from the southwestern China. Most disease indexes of the three cultivars were four or five degrees. And pathogenicity frequencies among the three cultivars were diverse for each isolate. Meanwhile, the average lesion lengths of the cultivars 93-11, YSBR1 and Kitaake were 0.56, 0.54 and 0.66 cm, respectively, whereas the average lesion numbers were 6.50, 4.10 and 4.80, respectively. In addition, there were significant correlations among the four evaluation indexes based on the analysis of Spearman correlation. The results showed that all of the three cultivars, 93-11, YSBR1, and Kitaake, exhibited resistance to most of the 36 M.oryzae isolates with differential resistance spectrums, and there was no significant difference among the four evaluation indexes for analyzing resistance spectrum.