Construction of a compound microbial agent for biocontrol against Fusarium wilt of banana

Abstract

Banana wilt caused by Fusarium oxysporum f. sp. cubense has devastated a large number of banana plantations worldwide. Biological control is a possible method to conquer this disease. However, the control effect was often low and unstable while a single biocontrol strain had been applied in the field. Therefore, this study aimed to construct an effective compound microbial agent to control Fusarium wilt of banana (FWB) in the field. In addition to it, the compounding strategy of combining single strains for improving the control effect was investigated. Based on the compatibility test, five representative biocontrol strains were selected for the combination of all possible permutations. The pot experiment indicated that every biocontrol strain and their 26 combinations could control FWB to varying degrees. The control effect of combinations on FWB was higher than that of a single strain. In terms of the number of combinatorial biocontrol strains, the control effect of the four-strain combinations was the highest. According to the taxonomic differences of the five biocontrol strains, 26 biocontrol strain combinations could be divided into four groups. Among the strains in the combination, the larger the taxonomic differences the more easily it was to obtain a higher control effect. To obtain stable and efficient combinations, eight combinations were selected out and evaluated for their effectiveness in controlling FWB in different type soil. Compared with the other seven combinations, the four-strain combination T28 (Pt05 + Bc11 + Ba62 + gz-2) got the highest and stablest control effect in the four types of soil in greenhouse. And then the control effect of combination T28 was evaluated in field conditions, compared with commercially agents Bacillus subtilis, Trichoderma harzianum, and carbendazim. After four consecutive applications in the field, the control effect of T28 against FWB was the highest, reaching 57.14%. The results showed that combination T28 had a good application prospect, and the finding provided a reference for the construction of compound microbial agents.

Effectiveness of a novel compound microbial agent for water quality and the gut microbiota of Micropterus salmoides

“…The impact of microbial agents on the water quality of aquaculture system has garnered increasing attention from researchers (Hoseinifar et al, 2023). In the present study, compared to the control, CMA treatment delayed the increase of pH (a decline of 2.96%), improved the DO value (a rise of 4.63%), and inhibited the eutrophication of M. salmoides aquaculture system by decreasing levels of ammonia nitrogen (a decline of 41.75%), nitrite (a decline of 19.35%), total phosphorus (a decline of 9.04%), and total nitrogen (a decline of 22.45%) at 7 d. Meanwhile, the water quality of CMA treated group was better than that of SAM treated group, suggesting that the application of microbial agents effectively improved the water quality of M. salmoides aquaculture system, with CMA treatment yielding superior It has proven that the efficacy of CMA in controlling Fusarium oxysporum in banana surpassed that of SMA, with a more distinct strain classification leading to enhanced control effects (Du et al, 2022), corroborating our results.…”

“…Therefore, improving water quality is of great significance for the cultivation of M. salmoides. Recent have revealed that the of microbial agents alters the overall quality of soil by modifying the bacterial community structure and the chemical properties (Du et al, 2022;Ahsan et al, 2023;Wang et al, 2023). The impact of microbial agents on the water quality of aquaculture system has garnered increasing attention from researchers (Hoseinifar et al, 2023).…”

Fusarium Tropical Race 4 in Latin America and the Caribbean: status and global research advances towards disease management

“…Trichoderma spp. is by far the most studied fungi for controlling FWB ( Bubici et al., 2019 ; Damodaran et al., 2020 ; Du et al., 2022 ; Zhang et al., 2022 ). Being a multipurpose microorganism, Trichoderma spp., utilizes direct antagonism and competition in the rhizosphere, colonizes plant roots (externally and/or as an endophyte), and has the capacity to promote plant growth and prime local and systemic defense responses against biotic stresses.…”

“…In China, where Foc TR4 is widely distributed and has devastated thousands of hectares of bananas, biocontrol strategies based on the combination of microorganisms have also been explored with encouraging results under field conditions ( Lin and Ho, 2021 ; Du et al., 2022 ; Zhu et al., 2023 ).…”