ABSTRACT

The prevention and control of strawberry grey mould are typically done via the traditional application of fungicides or spraying of fungal spores. However, the exploitation of honeybees for dissemination of biocontrol agents during pollination is more environment-friendly. To evaluate the feasibility of this novel strategy in dispersing fungal spores on strawberry plants, we first investigated the toxicological effect of Trichoderma harzianum spores on the eastern honeybee, Apis cerana cerana. Then, we evaluated the dissemination efficiency of spore powder, the optimal type and dilution ratio of dispersants, and the efficacy of fungal control in a strawberry greenhouse experiment. The results revealed that no acute oral toxicity/ low contact toxicity of T. harzianum on A. cerana cerana. The number of spores carried by bees reached maximum after a three-minute contact between the bees and T. harzianum spore powder, and the number of spores released by the bees was maximum after five minutes. We demonstrated that the application of dispersants, such as wheat flour, could mitigate the decline in the spore carrying capacity of bees caused by high humidity levels. Greenhouse experiments showed that bees could successfully deliver the spores to strawberry petals. The average number of spores deposited on strawberry flowers was 1.31×10 ⁶ CFU/flower, which was effective in controlling the grey mould in the field. Our study provides novel insights into the application of indigenous bee species to disseminate T. harzianum spore powder to control and prevent the strawberry grey mold, under both laboratory and greenhouse conditions.

摘要

草莓灰霉病的预防和控制通常通过传统的杀菌剂施用或喷洒真菌孢子来完成。但是，在授粉过程中利用蜜蜂传播生物控制剂更为环境友好。为了评估该新策略在草莓植物上散布真菌孢子的可行性，我们首先研究了哈茨木霉菌孢子对东部蜜蜂Acers cerana cerana的毒理作用。然后，我们评估了草莓温室实验中孢子粉的传播效率，分散剂的最佳类型和稀释比以及真菌控制的功效。结果表明，哈茨木霉无急性口服毒性/低接触毒性在cerana cerana上。蜜蜂和哈茨木霉孢子粉接触三分钟后，蜜蜂携带的孢子数量达到最大值，五分钟后蜜蜂释放的孢子数量达到最大值。我们证明了使用分散剂（例如小麦粉）可以减轻由于高湿度引起的蜜蜂孢子携带能力的下降。温室实验表明，蜜蜂可以成功地将孢子传递到草莓花瓣上。草莓花上的平均孢子数为1.31×10 ⁶ CFU /花，可有效控制田间灰霉病。我们的研究为应用本土蜂种进行传播提供了新颖的见解在实验室和温室条件下，哈茨木霉孢子粉可控制和预防草莓灰霉病。