哈茨木霉及贝莱斯芽孢杆菌土壤宿存探究

Study on the Soil Persistence of Trichoderma harzianum and Bacillus velezensis

摘要: 小麦赤霉病是由镰孢属多种镰刀菌侵染引起的，广泛存在于全世界小麦种植区的一种严重病害。我们此前的研究发现，哈茨木霉和贝莱斯芽孢杆菌在田间能显著减少小麦赤霉病的发病率，但对其防效的持续时间还未可知，因此，通过本次实验，对这两种生防菌在土壤中的生存情况和宿存动态进行探究，发现哈茨木霉和贝莱斯芽孢杆菌能在土壤中长期存在，尼龙纱网笼实验中的两种菌的宿存率分别为29%和52%，均显著高于大田实验的1.3% (p = 0.0007)和3% (p = 1.18 × 10⁻⁷)，说明为了获得良好的防治效果初始年份每年都需要重复施药，待积累一定带菌量后，可适当减少用药量和防治次数。

Abstract: Wheat head blight is caused by some Fusariums of Fusarium genus. It is a serious disease that widely exists in wheat planting areas all over the world. Our previous studies found that Trichoderma harzianum and Bacillus velezensis can significantly reduce the incidence rate of wheat head blight, but the duration of its control is unknown. Therefore, through this experiment, we explored the survival and persistence dynamics of these two biocontrol bacteria in soil, and found that Trichoderma harzianum and Bacillus velezensis can exist in soil for a long time. The survival rates of the Trichoderma harzianum and Bacillus velezensis were 29% and 52% respectively in the Nylon mesh cage experiment, which were significantly higher than 1.3% (p = 0.0007) and 3% (p = 1.18 × 10⁻⁷) of the field experiment, indicating that repeated application of pesticides was needed every year in order to obtain good control effect. After accumulating a certain amount of microorganism, the dosage and the times of control can be reduced properly.