水稻抗纹枯病接种鉴定方法评价

Evaluation of Inoculation and Identification Methods for Rice Sheath Blight Resistance

【目的】水稻纹枯病的抗性鉴定易受环境中温度、湿度及水稻株高和生育期等的影响,不同学者在水稻抗纹枯病遗传研究中采用的接种鉴定方法不同,寻找一种科学的水稻抗纹枯病接种鉴定方法至关重要。【方法】以已知抗、感纹枯病差异明显的8个水稻品种为试验材料,比较评价了前人研发的8种水稻抗纹枯病接种鉴定方法:离体叶片法、苗期微室法、苗期雾室法、苗期Parafilm小袋法、成株期谷壳散布法、成株期田间嵌入法、成株期雾室法、成株期铝箔包裹法。【结果】水稻纹枯病主要是叶鞘病害,离体叶片法虽操作简单,但基于叶片部位接种的离体叶片法和Parafilm小袋法的鉴定结果与其它6种方法的结果不具有显著相关性,这2种方法不能真正反应水稻品种对纹枯病的抗性,不适用于水稻纹枯病的抗性鉴定。成株期谷壳散布法操作粗放,发病不一致,重复性较差,可作为前期大规模品种抗病的初步筛选,但不适合表型鉴定等要求准确量化的抗病QTL定位研究。成株期雾室法和铝箔包裹法虽然纹枯病抗性鉴定结果较准确,但操作繁琐,需要精确的控温、控湿和光照设备,同样不适合大规模的表型抗性鉴定。苗期微室法、苗期雾室法和成株期田间嵌入法操作相对简单,接种后抗性鉴定结果差异显著,与品种的实际抗性水平吻合,结果重复性好,3种方法之间的相关性均达极显著水平。【结论】苗期微室法、苗期雾室法和成株期田间嵌入法3种水稻纹枯病接种鉴定方法适合大规模水稻抗性鉴定和遗传分析,研究结果明确了简便、准确、客观、适用的水稻抗纹枯病鉴定方法,为水稻抗纹枯病鉴定和抗性遗传育种育种提供便利。

[Objective]The identification of rice resistance to sheath blight(SB)is easily affected by environmental temperature,humidity,plant height and growth stages of rice.Different scholars adopted different inoculation identification methods in genetic research of rice sheath blight resistance,so it is very important to find a scientific inoculation identification method for rice sheath blight resistance[.Method]Eight rice varieties with obvious differences in resistance and susceptibility to sheath blight were used as experimental materials,and eight inoculation identification methods for resistance to sheath blight of rice developed by predecessors were compared and evaluated,including detached leaf method(SBL),micro-chamber method(SBI),mistchamber method at the seedling stage(SBM),parafilm sachet method(SBP),grain-spreading method(SBS),toothpick-inserting method(SBF),mist-chamber method at the adult stage(SBMA),and aluminum foil method(SBA)[Result]Rice sheath blight is mainly caused by leaf sheath disease.Although the isolated leaf method is simple to operate,SBL and SBP based on leaf inoculation have no significant correlation with the results of the other six methods.These two methods can not really reflect the resistance to rice sheath blight of susceptible control varieties,and are not suitable for identification of resistance to rice sheath blight.SBS has extensive operation,inconsistent incidence and poor repeatability,which is suitable for the preliminary screening of largescale disease-resistant varieties in the early stage,but it is not suitable for the mapping study of disease-resistant QTLs which requires accurate quantification in phenotypic identification.Although SBMA and SBA are accurate in phenotypic identification,they are cumbersome to operate,require precise temperature control,humidity control and illumination equipment,and are not suitable for large-scale phenotypic resistance identification.SBI,SBM and SBF are relatively simple to operate.The results of resistance identification after inoculation are significantly different,which are consistent with the actual resistance levels of varieties.The results are reproducible,and the correlation among the three methods is extremely significant.[Conclusion]SBI,SBM and SBF are suitable for large-scale rice resistance identification and genetic analysis.The results showed that the identification methods for rice sheath blight resistance are simple,accurate,objective and applicable,which provides convenience for identification and genetic breeding of rice sheath blight resistance.