梨锈病田间发病规律及相关性分析

【目的】研究梨锈病田间发病规律及发病影响因素，为梨锈病抗病性鉴定提供科学依据。【方法】以翠冠×金星杂交梨苗为试材，采用田间发病和人工接种鉴定方法，对梨锈病发病规律及抗性进行相关性分析。【结果】梨杂交实生苗对梨锈病的抗性表现出广泛的分离，不同年份梨杂交实生苗锈病病情指数概率分布差别较大；田间发病条件下，病害分布呈多峰型，人工接种呈单峰型；同一年份不同时期杂交实生苗对梨锈病的抗病性不一致；梨锈病病情指数与桧柏和梨树间的距离呈极显著负相关，相关性逐年增强。【结论】梨树杂交苗单株对梨锈病抗性年份间有差异，同一年内不同时期也不一致；对锈病人工接种鉴定，应进行多次接种，才能筛选出综合抗性较强的单株；进行田间抗性鉴定时应考虑梨树与桧柏距离对病害的影响。

Field incidences of pear rust(Gymnosporangium haraeanum Syd.) and its correlation with other factors

Objective]The incidence of pear rust(Gymnosporangium haraeanum Syd.) in field and influencing factors were studied in order to provide scientific reference for identifying pear rust resistance.Method]Hybrid seedlings of Cuiguan× Jinxing were used for investigating the pear rust incidences using natural rust infection in field and artificial inoculation method,and correlation analysis was conducted with other factors.Result]Rust-resistance in the hybrids seedling showed extensive segregation.Probability distribution of rust disease index of pear seedling varied greatly among different years and different periods in the same year.The distribution curve of disease showed multi-peaks under field conditions.While,it showed single peak in case of artificial inoculation.Moreover,a significantly negative correlation was observed between distance of juniper and pear and disease index,which increased year after year.Conclusion]Rust-resistance of pear seedling varied in different years or even in the same year.This difference might be due to the infection of different physiological race of pear rust.Therefore,the pathogen should be artificially inoculated many times to select highly resistant strain,and the distance between pear and juniper plants should be considered in screening stronger rust-resistant pear variety in field.