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期 刊 ：植物保护学报 2010年

关键词：水稻；稻绿核菌；品种；生育期；发病率；

Keywords:rice, Ustilaginoidea virens, cultivar, maturity group, disease severity,

摘 要 ：利用早熟组和晚熟组各8个水稻品种采用随机区组设计连续进行两年田间试验,分析生育期与稻曲病严重度的关系,同时采用晚熟组5个品种分析田间厚垣孢子数量、播期与稻曲病发生严重度的关系。结果表明,水稻生育期、田间菌量与稻曲病田间发生的严重度呈显著正相关。早熟组各水稻品种的发病率均显著低于晚熟组各水稻品种,2005年晚熟组和早熟组品种的病穴率、病穗率和病粒率分别为76.3%、26.6%、4.6%和5.4%、0.8%、0.02%, 2006年分别为75.7%、29.8%、4.7%和16.8%、3.3%、0.08%。此外,在上一年田间遗落菌量多的田块中各水稻品种稻曲病的发生程度显著高于菌量小的田块。晚熟组水稻品种的发病严重度与播种期无明显的相关性。

Abstract:In this study, early and late maturity rice cultivars were grown in the fields to investigate the effect of maturity group of cultivar, pathogen amount and sowing date on the severity of rice false smut. From our results, we identified three important correlations. First, the severity of rice false smut was dependent on the amount of chlamydospores present in the experimental field plot. Second, there was significant correlation between the disease severity and cultivar maturity, and late maturity cultivars were significantly more susceptible than early maturity cultivars. The percentage of diseased hills (DH), diseased panicles (DP) and diseased spikelets (DS) of late maturity cultivars was 76.3%, 26.6% and 4.6% in 2005, and 75.7%, 29.8% and 4.7% in 2006, respectively, whereas, DH, DP and DS of early maturity cultivars was 5.4%, 0.8% and 0.02% in 2005, and 16.8%, 3.3% and 0.08% in 2006, respectively. Third, there was no correlation between the disease severity of late maturity cultivars and sowing dates. It was suggested to decrease the severity of false smut by planting the early maturating group cultivars or using crop rotation to reduce inoculum in rice growing regions in northern China, where false smut of rice severely outbreaks.

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