Carisse O, Van der Heyden H
Agriculture and Agri-Food Canada, 430 Gouin Boulevard, St-Jean-sur-Richelieu, Quebec, Canada J3B 3E6.
Compagnie de recherche Phytodata Inc., 291 Rue de la coopérative, Sherrington, Québec, Canada, J0l 2N0.
Plant Dis. 2015 Jan;99(1):137-142. doi: 10.1094/PDIS-05-14-0490-RE.
Gray mold, caused by Botrytis cinerea, is an important threat for tomato greenhouse producers. The influence of airborne conidia concentration (ACC) on both flower and stem-wound infections was studied in a greenhouse maintained at a temperature of 15, 20, or 25°C using diseased tomato leaves as the unique source of dry inoculum. Spore samplers were used to monitor ACC, and a previously developed real-time qPCR assay was used to quantify airborne B. cinerea conidia. The proportion of infected flowers remained low at ACC < 10 conidia/m; above this concentration, flower infection increased with increasing ACC. The influence of ACC on proportion of infected flowers was well described by a sigmoid model (R = 0.90 to 0.92). The mean proportion of infected stem wounds over the three trials was 0.021; no infected wounds were observed at ACC < 100 conidia/m. Based on logistic regression, the probability that a stem becomes infected increased rapidly with mean probabilities of 0.24 and 0.87 at ACCs of 315 and 3,161 conidia/m, respectively. The results suggest that the amount of airborne B. cinerea inoculum in the greenhouse is often above the action threshold for flower infection and that monitoring airborne B. cinerea inoculum could help in timing de-leafing operations.
由灰葡萄孢引起的灰霉病是番茄温室种植者面临的一个重要威胁。在温度保持在15、20或25°C的温室中，以患病番茄叶片作为唯一的干接种源，研究了空气中分生孢子浓度（ACC）对花朵和茎伤口感染的影响。使用孢子采样器监测ACC，并使用先前开发的实时定量PCR检测法定量空气中的灰葡萄孢分生孢子。在ACC < 10个分生孢子/立方米时，受感染花朵的比例仍然较低；高于此浓度时，花朵感染率随ACC增加而上升。用S形模型能很好地描述ACC对受感染花朵比例的影响（R = 0.90至0.92）。在三项试验中，受感染茎伤口的平均比例为0.021；在ACC < 100个分生孢子/立方米时未观察到受感染的伤口。基于逻辑回归分析，茎被感染的概率随着ACC的增加而迅速上升，在ACC分别为315和3161个分生孢子/立方米时，平均概率分别为0.24和0.87。结果表明，温室中空气中灰葡萄孢接种量通常高于花朵感染的行动阈值，监测空气中灰葡萄孢接种量有助于确定去叶操作的时机。
