应用相对抗病性指数评价胡萝卜种质资源黑腐病抗性

研究旨在建立胡萝卜苗期黑腐病品种抗病性鉴定方法，并筛选出胡萝卜黑腐病抗病种质资源。通过连续2年同一地块苗期人工喷雾接菌方法对胡萝卜种植资源进行胡萝卜黑腐病抗性鉴定，应用相对抗病性指数和聚类分析方法建立品种抗病性评价标准，对供试品种进行品种抗病性分析。依据相对抗病性指数进行聚类分析，确定胡萝卜黑腐病品种抗性类型划分标准为：高抗(HR)，RRI≥1.4；抗病(R)，1.1≤RRI＜1.4；中抗(MR)，0.5≤RRI＜1.1；感病(S)，0.1≤RRI＜0.5；高感(HS)，RRI＜0.1。供试11个品种中高抗品种2个、抗性品种3个、中抗品种3个、感病品种1个、高感品种2个。试验建立了胡萝卜品种田间抗病性鉴定方法和评价标准，可为胡萝卜抗病育种研究和田间种植品种选择提供理论依据。

Evaluation of Resistance to Carrot Black Rot According to Relative Resistance Index

The method of evaluating resistance to carrot black rot at seedling stage was established and the resistant varieties were screened. Identification of disease resistance to carrot black rot was performed by artificial spray inoculation at seedling stage of the carrot in the same field for two years, the evaluation standard of resistance types was established and clustering analysis of carrot varieties was evaluated according to relative resistance index (RRI) comparison. The evaluation standard of resistance was establish as: HR, RRI≥ 1.4; R, 1.1≤RRI＜1.4; MR, 0.5≤RRI＜1.1; S, 0.1≤RRI＜0.5; HS, RRI＜0.1. The tested carrot varieties including two varieties of high resistant type, three varieties of resistant type, three varieties of middle resistant type, one variety of middle resistance sensitive type and two varieties of high sensitive type. The method and the standard of resistance evaluation to carrot black rot in this study could be the basis for resistance breeding and species selection.