Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences, Integrated Pest Management Innovation Centre of Hebei Province, Baoding 071000, China.
Toxins (Basel). 2023 Jun 5;15(6):381. doi: 10.3390/toxins15060381.
Fusarium wilt, caused by , is one of the most notorious diseases of cash crops. The use of microbial fungicides is an effective measure for controlling Fusarium wilt, and the genus is an important resource for the development of microbial fungicides. Fusaric acid (FA) produced by can inhibit the growth of , thus affecting the control efficacy of microbial fungicides. Therefore, screening FA-tolerant biocontrol may help to improve the biocontrol effect on Fusarium wilt. In this study, a method for screening biocontrol agents against Fusarium wilt was established based on tolerance to FA and antagonism against . Three promising biocontrol bacteria, named B31, F68, and 30833, were obtained to successfully control tomato, watermelon, and cucumber Fusarium wilt. Strains B31, F68, and 30833 were identified as by phylogenetic analysis of the 16S rDNA, , and gene sequences. Coculture assays revealed that strains B31, F68, and 30833 showed increased tolerance to and its metabolites compared with strain FZB42. Further experiments confirmed that 10 µg/mL FA completely inhibited the growth of strain FZB42, while strains B31, F68, and 30833 maintained normal growth at 20 µg/mL FA and partial growth at 40 µg/mL FA. Compared with strain FZB42, strains B31, F68, and 30833 exhibited significantly greater tolerance to FA.
镰刀菌枯萎病是经济作物的一种最严重病害之一，由 引起。使用微生物杀菌剂是控制镰刀菌枯萎病的有效措施，而 属是开发微生物杀菌剂的重要资源。 产生的镰刀菌酸（FA）可以抑制 的生长，从而影响微生物杀菌剂的控制效果。因此，筛选 FA 耐受型生防菌可能有助于提高对镰刀菌枯萎病的生物防治效果。本研究建立了一种基于 FA 耐受和拮抗作用筛选生防剂的方法，成功防治了番茄、西瓜和黄瓜枯萎病。获得了 3 株有前途的生防细菌，分别命名为 B31、F68 和 30833。通过 16S rDNA、 和 基因序列的系统发育分析，菌株 B31、F68 和 30833 被鉴定为 。共培养试验表明，与 菌株 FZB42 相比，菌株 B31、F68 和 30833 对 和其代谢产物的耐受性增加。进一步的实验证实，10μg/mL 的 FA 完全抑制了菌株 FZB42 的生长，而菌株 B31、F68 和 30833 在 20μg/mL FA 下保持正常生长，在 40μg/mL FA 下部分生长。与菌株 FZB42 相比，菌株 B31、F68 和 30833 对 FA 表现出明显更高的耐受性。
