Wu Xiaoyan, Shan Ying, Li Yi, Li Qinfen, Wu Chunyuan
Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Danzhou, China.
Front Plant Sci. 2020 Nov 16;11:599904. doi: 10.3389/fpls.2020.599904. eCollection 2020.
Biological control agents (BCAs) are considered as one of the most important strategies for controlling wilt, and bioorganic fertilizer, in particular, has been extensively investigated. However, little is known regarding how a biocontrol microorganism affects the suppression mechanisms when combined with different amendments. In this study, a pot experiment was performed using banana plants to investigate the different mechanisms by which the biocontrol bacterium HN03 (isolated from our laboratory) and amendments suppress wilt. The incidence of banana wilt was decreased under HN03 and was reduced further when HN03 was combined with compost, particularly wormcast. In the suppression of wilt, HN03 was found to influence the soil environment in various ways. HN03 increased the peroxidase level, which improves plant defense, and was highest when combined with wormcast, being 69 times higher than when combined with cow dung compost. The high accumulation of Mg and P in the "HN03 + wormcast" and Zn and Mn in the "HN03 + cow dung" treatments was negatively correlated with disease incidence. Furthermore, HN03 re-established the microbial community destroyed by the pathogen and further increased the level of suppression in the wormcast. HN03 also enhanced the functional traits of the soil, including defensive mechanism-related traits, and these traits were further enhanced by the combination of HN03 + wormcast.
生物防治剂（BCAs）被认为是控制枯萎病最重要的策略之一，尤其是生物有机肥，已经得到了广泛研究。然而，对于生物防治微生物与不同改良剂结合时如何影响抑制机制，人们了解甚少。在本研究中，利用香蕉植株进行了盆栽试验，以探究生物防治细菌HN03（从我们实验室分离得到）和改良剂抑制枯萎病的不同机制。在HN03处理下香蕉枯萎病的发病率降低，当HN03与堆肥，特别是蚯蚓粪结合时，发病率进一步降低。在抑制枯萎病方面，发现HN03以多种方式影响土壤环境。HN03提高了过氧化物酶水平，从而增强了植物防御能力，与蚯蚓粪结合时过氧化物酶水平最高，比与牛粪堆肥结合时高69倍。“HN03 + 蚯蚓粪”处理中Mg和P的高积累以及“HN03 + 牛粪”处理中Zn和Mn的高积累与发病率呈负相关。此外，HN03重新建立了被病原菌破坏的微生物群落，并进一步提高了蚯蚓粪中的抑制水平。HN03还增强了土壤的功能特性，包括与防御机制相关的特性，并且HN03 + 蚯蚓粪的组合进一步增强了这些特性。
