不同菜心品种对霜霉病的抗性鉴定OA

[Objective]With the aim of screening out disease-resistant varieties for promotion in production,differences in disease-resistance of different varieties of flowering Chinese cabbage to downy mildew were analyzed.[Method]Fresh leaves of flowering Chinese cabbage infec-ted with downy mildew bacteria were collected from the field.The swimming sporangia were washed off with clean water and prepared into a sporangia suspension.The varieties were inoculated by spray method with a concentration of 2×103 spores per milliliter.The disease index was investigated for resistance grading to evaluate the differences in resistance to downy mildew among different varieties of flowering Chinese cab-bage.[Result]The results showed that the average disease index of 52 cultivars ranged from 39.26 to 70.12,among which 16 were moderate-ly resistant,35 were susceptible,and 1 was highly susceptible,accounting for 30.8%,67.3%,and 1.9%of the tested materials respective-ly.Yuetai No.8 had the highest average disease index(70.12)and Yuetai No.4 had the lowest average disease index(39.26).There were significant differences in disease index among varieties of flowering Chinese cabbage.[Conclusion]The research provides scientific data for breeding and promotion of flowering Chinese cabbage varieties resistant to downy mildew.The application and promotion of disease-resistant varieties help reduce pesticide usage,protect environment and increase yields,which is of great significance to agricultural production and food safety.