Parsa Soroush, Ortiz Viviana, Vega Fernando E
Entomology, International Center for Tropical Agriculture (CIAT), Cali, Colombia.
J Vis Exp. 2013 Apr 11(74):50360. doi: 10.3791/50360.
Beauveria bassiana is a fungal entomopathogen with the ability to colonize plants endophytically. As an endophyte, B. bassiana may play a role in protecting plants from herbivory and disease. This protocol demonstrates two inoculation methods to establish B. bassiana endophytically in the common bean (Phaseolus vulgaris), in preparation for subsequent evaluations of endophytic biological control. Plants are grown from surface-sterilized seeds for two weeks before receiving a B. bassiana treatment of 10(8) conidia/ml (or water) applied either as a foliar spray or a soil drench. Two weeks later, the plants are harvested and their leaves, stems and roots are sampled to evaluate endophytic fungal colonization. For this, samples are individually surface sterilized, cut into multiple sections, and incubated in potato dextrose agar media for 20 days. The media is inspected every 2-3 days to observe fungal growth associated with plant sections and record the occurrence of B. bassiana to estimate the extent of its endophytic colonization. Analyses of inoculation success compare the occurrence of B. bassiana within a given plant part (i.e. leaves, stems or roots) across treatments and controls. In addition to the inoculation method, the specific outcome of the experiment may depend on the target crop species or variety, the fungal entomopathogen species strain or isolate used, and the plant's growing conditions.
球孢白僵菌是一种能够内生定殖于植物的真菌性昆虫病原体。作为一种内生菌，球孢白僵菌可能在保护植物免受食草动物侵害和疾病方面发挥作用。本方案展示了两种接种方法，用于在菜豆（Phaseolus vulgaris）中内生定殖球孢白僵菌，为后续内生生物防治评估做准备。在接受10⁸ 个分生孢子/毫升（或水）的球孢白僵菌处理（通过叶面喷雾或土壤浇灌施用）之前，将表面灭菌的种子培育两周。两周后，收获植株，并对其叶片、茎和根进行采样，以评估内生真菌定殖情况。为此，将样本分别进行表面灭菌，切成多个部分，并在马铃薯葡萄糖琼脂培养基中培养20天。每2 - 3天检查一次培养基，观察与植物切片相关的真菌生长情况，并记录球孢白僵菌的出现情况，以估计其内生定殖程度。接种成功率分析比较了不同处理和对照下给定植物部位（即叶片、茎或根）内球孢白僵菌的出现情况。除接种方法外，实验的具体结果可能取决于目标作物种类或品种、所使用的真菌性昆虫病原体种类菌株或分离株以及植物的生长条件。
