ABSTRACT

This study was conducted to investigate the effect of Bacillus amyloliquefaciens Y1 on the control of grey mould disease caused by Botrytis cinerea and subsequent growth promotion of strawberry. Strain Y1 strongly inhibited mycelial growth of B. cinerea on different media with the highest inhibition of 61.22% on V8 juice agar medium. The higher the bacterial culture filtrate (BCF) concentration of strain Y1 blended in the PDA medium, the stronger the rate of inhibition on mycelial growth of B. cinerea. Microscopic observation revealed that the hyphal structure of the fungal pathogen was severely affected by the BCF indicating abnormal growth with excessive branching and swelling. Strain Y1 showed the promising ability to suppress grey mould disease under in vivo conditions and significantly lessened disease severity on flowers and fruits leading to an increase in disease control value when compared to fungicide treatment. Moreover, application of strain Y1 resulted in a significant promotion of strawberry plants with higher values in most growth characteristics compared to other treatments. The detection of higher levels of the defence-related enzyme, β-1,3-glucanase in the Y1-treated plants indicated that induction of resistance by this strain was at least partly involved in disease suppression. Even though there were reductions in the overall numbers of the soil bacterial population in the Y1-treated plants, no significant impact on the growth of strawberry was observed. Based on our results, strain Y1 is a promising candidate for environment-friendly disease control strategies.

摘要

进行本研究以研究解淀粉芽孢杆菌Y1对灰葡萄孢引起的灰霉病的控制以及草莓随后的生长促进的作用。Y1菌株在不同培养基上强烈抑制灰葡萄孢菌的菌丝生长，在V8汁琼脂培养基上最高抑制61.22％。PDA培养基中掺入的菌株Y1的细菌培养滤液（BCF）浓度越高，对灰葡萄孢菌的菌丝体生长的抑制率就越强。显微镜观察表明，真菌病原体的菌丝结构受到BCF的严重影响，表明其异常生长，具有过度的分支和肿胀。Y1菌株显示出在体内抑制灰霉病的有希望的能力与杀真菌剂处理相比，花卉和水果的病害状况和病害严重程度大大降低，导致疾病控制价值的提高。此外，与其他处理相比，菌株Y1的施用显着促进了草莓植株在大多数生长特性方面具有更高的价值。在Y1处理的植物中检测到较高水平的防御相关酶β-1,3-葡聚糖酶表明，该菌株的抗性诱导至少部分参与了疾病抑制。尽管用Y1处理过的植物中土壤细菌种群总数减少了，但未观察到对草莓生长的显着影响。根据我们的结果，Y1菌株是环境友好型疾病控制策略的有希望的候选者。