葡萄叶片叶绿素质量分数与其霜霉病抗性的关系
Effects of Leaf Chlorophyll Mass Fraction on Grape Cultivar Resistance to Plasmopara viticola

对甘肃省8个不同鲜食葡萄品种进行抗性鉴定，并研究叶片叶绿素质量分数与霜霉病抗性的关系。结果表明，‘醉人香’‘高妻’和‘夏黑’为抗病品种，‘红地球’和‘奥古斯特’为感病品种，‘瑞必尔’‘金秀’和‘火焰核’为高感品种。葡萄叶片内叶绿素总质量分数和品种与霜霉病的抗性不显著相关，但叶片叶绿素总质量分数降幅与霜霉病的抗性呈显著负相关，即叶片叶绿素总质量分数降幅与叶片病情指数呈显著正相关。叶片叶绿素总质量分数降幅低于30%时，品种表现为明显抗病；降幅为30%～40%时，品种表现为感病；而降幅高于40%时，品种表现为高感。表明，葡萄叶片叶绿素总质量分数降幅可作为葡萄对霜霉病抗性鉴定的辅助指标。
In order to provide scientific basis for breeding of resistant cultivars and its control in Gansu,resistance of different grape cultivars to Plasmopara viticola were determined through inoculating leaf plates indoors and disease survey in the field,and effects of leaf chlorophyll content on 8 grape cultivar resistance to Plasmopara viticola was studied.The results showed that ‘Zuirenxiang’‘Gaoqi’ and ‘Summer black’ were resistant to Plasmopara viticola,‘Red globe’ and ‘August’ were slightly susceptive or susceptive cultivars．Other 3 cultivars were high susceptive cultivars.Ttotal chlorophyll mass fraction in grape leaves had no significant correlation with the resistance of different grape varieties to downy mildew.But the percentage decline of total chlorophyll mass fraction in the leves and resistance to downy mildew in different grape varieties were significantly negative correlation;namely,the leaf disease index of varieties and decreased percentages of leaf total chlorophyll mass fraction showed significantly positive correlation.The study also found that grape varieties had strong resistance to rape downy mildew when the percentage decline of total chlorophyll mass fraction in grape leaves was below 30 percent ; it was slight susceptive when the percentage decline of total chlorophyll mass fraction in grape leaves was between 30 percent and 40 percent ; it was the more susceptive when the percentage decline of total chlorophyll mass fraction in grape leaves was above 40 percent.Therefore the percentage decline of total chlorophyll mass fraction in grape leaves should be selected as a supplementary index to assess the resistance of grape to Plasmopara viticola while the index could reflect the resistance .