水稻抗纹枯病苗期快速鉴定技术研究

 以抗感反应不同的5个水稻品种为试验材料,在人工气候箱、控温室中进行水稻苗期抗纹枯病接种试验,并与田间相应的成株期抗性试验进行比较,研究水稻苗期快速鉴定技术。结果表明:85%的相对湿度为纹枯病菌侵染危害水稻苗期植株的适宜湿度;苗期5个水稻品种对纹枯病抗性差异极显著,可将其分为相对感病(Lemont、武育粳3号)和相对抗病(YSBR1、Jasmine85、特青)2大类;接种叶龄对发病程度有显著的影响,5个品种在四叶期接种时的平均病级显著高于五叶期接种的平均病级;苗期水稻品种间抗感差异小于田间鉴定试验结果,但两者间品种抗感趋势基本一致。苗期快速鉴定技术可用于大规模水稻品种(组合)的抗性筛选或初步鉴定。

Rapid identification technology of resistance to rice sheath blight in seedling stage

In order to establish a rapid identification technology of resistance to sheath blight (SB) in rice seedling stage,five cultivars with different resistance to SB were adopted in identification of seedling stage in artificial climate incubator or temperature-controlled greenhouse and the results were verified through an experiment at rice adult stage in field.The results showed that about 85% relative humidity was suitable for SB mycelium to develop infection structures and infect rice seedlings.The SB resistance levels among 5 cultivar seedlings differed significantly at 1% levels and could be divided into two groups,relatively susceptible (Lemont,Wuyujing 3) and relatively resistant (YSBR1,Jasmine 85,Teqing).The symptom severe degrees of seedlings at different leaf-age (4-leaf stage or 5-leaf stage) were significantly different and the average disease rating at 4-leaf stage was significantly higher than that of 5-leaf stage.The differences of resistance among different cultivars in greenhouse were less than that in the field,but the resistant-to-susceptible order among the cultivars were consistent with that in the field.Rapid identification technology of rice SB resistance in seedling stage could be used for screening resistance of rice germplasm on a large-scale scope or primary resistance identification.