葡萄白粉菌孢子扩散动态与田间病情相关性研究

Correlation between Conidial Dispersal Dynamics of Uncinula necator and Disease State in Vineyard

【目的】了解葡萄白粉菌分生孢子时空分布动态,并分析其与田间病情的相关性,为准确测报和防治提供依据。【方法】在葡萄生长期应用便携式孢子捕捉仪分别观测1 d内不同时间、不同高度及整个生长期白粉菌空中孢子数量。同时定点系统调查田间葡萄白粉病情,分析两者之间的相关性。【结果】分生孢子主要发生在每日10：00-22：00,14：00-16：00捕孢量最多而稳定;距地面1.5 m左右的捕孢量最大,冠层以上捕孢量随高度增加而逐次减少。2009年当地葡萄白粉菌分生孢子始见期在6月中旬,扩散期为6-9月,7月下旬-8月下旬为扩散盛期,9月后进入消退期。自捕捉到孢子5 d后田间开始陆续发病。葡萄生长期白粉菌孢子扩散量与田间病情的相关系数为0.83。【结论】葡萄白粉菌分生孢子释放扩散具有明显的昼夜周期性。孢子扩散主要发生在白天,扩散高峰期在14：00-16：00,大多分布在葡萄冠层以下,以1-2 m处最多。分生孢子扩散动态与田间病情扩展动态呈显著正相关。

【Objective】Spatial and temporal distribution of Uncinula necator were monitored and the correlation with disease state in vineyard was analyzed,which will provide a basis for disease prediction and forecast.【Method】Conidial dispersal were observed using the portable spore-traps during the whole growing season. And the correlation between conidial dispersal and disease state was analyzed.【Result】Conidial dispersal occurred mainly from 10：00 to 22：00,the maximum trapping occurred between 14：00 and 16：00 at 1.5 m apart from the ground.In 2009,the spores first appeared in the middle of June,and kept dispereal from June to September.From the end of July to the late of August,the dispersal reached the peak.While it decreased in September.The onset of disease was observed 5 days after the first appearance of spores.The dynamics of conidial dispersal was correlated with the disease incidence,and the correlation coefficient is 0.83.【Conclusion】Conidial dispersal of U.necator was a process with daily periodicity and occurred mainly during daytime,with a peak from 14：00 to 16：00.Most of spores flew under the vine canopy and the maximum appeared below 2 m.There was an evident direct pertinence bewteen conidial dispersal and disease levels.