贺兰山东麓酿酒葡萄霜霉菌孢子囊扩散与田间病情的相关研究

Diffusion of Plasmopara viticola sporangium and its correlation with disease incidence in vineyards in the eastern foot of Helan mountain

【目的】研究贺兰山东麓酿酒葡萄霜霉菌(Plasmopara viticola)孢子囊的田间扩散规律,揭示葡萄霜霉病田间流行机制,为该病的预测预报和防控提供理论依据。【方法】于2015-2017年,在贺兰山东麓酿酒葡萄园,采用定量风流孢子捕捉仪捕获田间葡萄霜霉菌孢子囊,监测孢子囊田间扩散数量,并结合田间病情指数和气象因子探讨孢子囊扩散规律,评估贺兰山东麓酿酒葡萄霜霉病的流行程度和主要气象影响因子。【结果】葡萄霜霉菌孢子囊在田间有10:00和24:00两个扩散高峰;孢子囊扩散在垂直方向上主要分布在近地面冠层,在水平方向上受葡萄叶幕阻隔形成多个孢子囊捕获中心;孢子囊扩散季节动态曲线呈倒"U"型,先缓慢上升后下降到一个较低的水平。田间孢子囊扩散数量与前7 d平均最低气温、前7 d平均温度、前7 d累计雨日和捕孢后第15天的田间病情指数呈显著或极显著正相关,相关系数分别为0.486(P<0.01),0.371(P<0.05),0.364(P<0.05)和0.636(P<0.01);与捕孢间隔期是否降雨和捕孢当日的田间病情指数呈显著负相关,相关系数分别为-0.559(P<0.05)和-0.378(P<0.05)。【结论】通过测定葡萄霜霉菌孢子囊扩散密度,并结合气象数据分析,可以预测葡萄霜霉病田间发生情况,为该病的早期预警和有效防控提供参考。

【Objective】 This study explored the diffusion regularity and epidemic mechanism of Plasmopara viticola sporangium in the field to provide basis for the prediction,prevention and control of grape downy mildew in the eastern foot of Helan mountain.【Method】 From 2015 to 2017,airborne sporangium density of P. viticola was monitored in vineyards by quantitative airborne spore catcher,and the diffusion regularity of P. viticola sporangium was studied by combining with disease index and meteorological factors in vineyards.Then,the prevalence of grape downy mildew was evaluated and the key influence factors of meteorological factors on grape downy mildew in the eastern foot of Helan mountain were determined.【Result】 Two diffusion peaks at 10:00 am and 12:00 pm were obtained for diffusion of P. viticola sporangium.Vertically the diffusion mainly distributed within the vineyard canopy while horizontally numbers of sporangium density centers existed due to the separation of grape leaves.The seasonal variation of P. viticola sporangium showed a shape of inverted "U",increasing slowly and then decreasing to a lower level.Airborne sporangium concentrations were significantly or highly significantly correlated with 7-day averaged low temperature,7-day averaged temperature,7-day accumulated rain days and disease index increment on the 15 th day with correlation coefficients of 0.486(P<0.01),0.371(P<0.05),0.364(P<0.05) and 0.636(P<0.01),respectively.On the contrary,it had negative correlation with rain or not in the interval of monitored sporangium and disease index of current day with correlation coefficients of-0.559(P<0.05) and-0.378(P<0.05),respectively.【Conclusion】 The combination of monitoring sporangium density and meteorological factors can be used to predict the occurrence of grape downy mildew in vineyards and provides new ideas for early warning and effective prevention and control of grape downy mildew.