以已知抗、感反应不同的5个水稻品种为试验材料,采用牙签嵌入法在控温室和田间进行水稻成株期不同阶段(分蘖末期、小孕穗期)抗纹枯病接种试验,并于接种后3~11 d、抽穗后30 d测量病斑长度并调查病级,研究水稻在成株期对纹枯病的抗性。结果表明:以病斑长度为调查指标,控温室中分蘖末期接种的5个水稻品种间抗感差异极显著,Lemont和YSBR1分别表现为稳定的感病和抗病,且与另外3个品种(武育粳3号、特青、Jasmine 85)差异极显著,各品种间的抗感趋势与田间抽穗后30 d的验证试验结果基本一致;而田间分蘖末期接种的5个水稻品种间虽然抗感差异极显著,但品种间抗感趋势与同期温室和田间抽穗后30 d的验证试验结果不一致。田间小孕穗期接种的5个水稻品种间抗感差异极显著,品种间抗感趋势与田间抽穗后30 d的试验结果完全一致。研究结果表明,温室条件下分蘖末期或田间条件下小孕穗期以病斑长度作为衡量纹枯病抗性的调查指标具有一定的可行性。
In order to study resistance performance of rice to sheath blight(SB), five rice cultivars with different levels of resistance to SB were inoculated with toothpick insertion inoculation methods during different times of rice adult stage in field and temperature-controlled greenhouse,and the lesion length during 3—11 days after inoculation,the SB disease rating at the 30th day after heading stage were investigated.The results were as follows: The SB resistance levels evaluated with the lesion length among 5 cultivars inoculated at the late tillering stage in temperature-controlled greenhouse differed significantly at 1% level and could be divided into three groups,relatively susceptible(Lemont),moderate susceptible to moderate resistant(Wuyujing 3,Jasmine 85,Teqing) and relatively resistant(YSBR1),and the resistant-to-susceptible order among five cultivars was consistent with the result of the 30th day after heading stage,which was achieved by verification trial in the field.Although the SB resistance levels among 5 cultivars inoculated at the same time in field differed also significantly at 1% level,the resistant-to-susceptible order among five cultivars was inconsistent with that of the 30th day after heading stage.Furthermore,the SB resistance levels among 5 cultivars inoculated at the small booting stage in field differed significantly at 1% level,and the resistant-to-susceptible order among five cultivars was consistent with that of the 30th day after heading stage.The results showed that the lesion length used as investigation index to evaluate rice SB resistance at the late tillering stage in greenhouse or at the booting stage in field was feasible.