寒地水稻纹枯病抗性鉴定指标的灰色关联分析

目的]明确寒地水稻纹枯病抗性鉴定的调查指标及鉴定时期。方法]利用苗期鉴定法和成株期牙签嵌入法分别于分蘖末期和抽穗期进行接种,并在苗期采用单株病情指数,成株期采用病级、相对病斑长度、病斑长度和绝对病斑高度为调查指标,进行抗性鉴定。结果]分蘖末期接种的3次调查中,病级、绝对病斑高度与抽穗期第3次调查的绝对病斑长度和病级的灰色关联度呈上升趋势,且分蘖末期接种的第3次调查中这2个指标与对照指标的灰色相关度分别为0.891 2、0.888 6和0.911 1、0.903 0。这2个指标可作为抗性鉴定重要参考指标。苗期鉴定的单株病情指数与2个对照指标的灰色相关度分别为0.746 1和0.787 9,表明苗期鉴定的调查指标与成株期鉴定的结果具有一定的相关性。结论]成株期牙签嵌入法在分蘖末期和抽穗期接种,接种后第36天调查的病级和绝对病斑高度可作为抗性鉴定和遗传分析的重要指标。苗期鉴定的单株病级指数与成株期鉴定结果具有一定的灰色关联度。

Grey Correlation Analysis on Resistance Identification Indexes of Rice Sheath Blight in Cold Region

Objective] The purpose of this study was to clear scientific and reliable investigation index and identification period for rice sheath blight resistance identification in cold region. Method] The resistance identification was carried out in seedling stage and adult plant stage, toothpick embedding method was used in adult plant identification in the stage of late tillering stage and heading stage;the investigation inde-xes were seedling disease index in seedling stage and disease rank, absolute disease height, relative disease length and disease length in adult plant stage. Result] The three investigation which were inoculated at late tillering stage, the grey correlation among disease rank, absolute disease height, relative disease length and disease length with absolute disease height, disease rank which were investigated in the third inves-tigation at heading stage inoculation were increased, and the grey correlation in the third investigation with the check index were 0.8912, 0.8886 and 0.9111, 0.9030 respectively.And the two indexes could be used as important indexes for resistance identification.The grey correlation among the seeding disease index at seeding identification with two check indexes were 0.7461 and 0.7879 respectively, which showed that the investigation index in seeding identification was associated with that of adult plant stage. Conclusion] The disease rank and absolute disease height of thirty-sixth days after inoculation in adult plant identification could be used as important indexes for resistance identi-fication and genetic analysis.There was a certain degree of grey correlation between seedling disease index in seedling stage and the results in adult plant identification.