Antifungal activities of endophytic fungi isolated from plantain tissues on Fusarium solani a potential pathogen

Endophytic fungi are part of microbial community found in various types of plant tissues and display a range of symbiotic interactions with the plant host, including plantain species. They are sustainable and less harmful alternatives to chemicals in controlling pathogens. Therefore, this study was aimed to isolate the endophytic fungal communities associated with the plantain Corn 1 in order to use them for the management of root rot disease incidence. Five endophytic fungi were isolated from healthy and symptomatic parts of the plantain variety Corn1 from farms in Southern Côte d’Ivoire. The analyses of the ITS region sequences revealed that the isolates from the healthy parts LBVM Ba.0001 and LBVM Ba.0006 had 99% and 100% homology with respectively Neosartorya laciniosa (FR733875.1) and Talaromyces assiutensis (KM458833.1). The strains LBVM Ba.0002 and LBVM Ba.0003 isolated from the symptomatic parts had 99% Fusarium solani (KT366735.1) while LBVM Ba.0005 had 100% homology with Nectria haematococca (AY310442.1). Both endophytes isolates LBVM Ba.0001 and LBVM Ba.0006 were tested for their ability to inhibit the growth of Fusarium solani using dual culture assays. The endophytic fungi inhibited Fusarium solani growth significantly (P ≤ 0.05) under in-vitro conditions. Neosartorya laciniosa showed the best biocontrol effect on Fusarium solani (IC50 = 0.8 g/L and IC90 = 7.6 g/L), compared to Talaromyces assiutensis (IC50 = 0.8 g/L and IC90 = 7.6 g/L).

内生真菌（endophytic fungi）是定殖于多种植物组织内的微生物群落的组成部分，可与植物宿主建立多样化的共生互作关系，大蕉属物种亦为其宿主类群之一。相较于化学防控药剂，内生真菌在植物病原菌治理方面具备可持续性且低毒的优势。因此，本研究旨在分离与大蕉品种‘Corn 1’相关的内生真菌群落，以期将其应用于根腐病害的防控。研究人员从科特迪瓦南部农场种植的大蕉品种‘Corn 1’的健康组织与显症组织中，分离得到5株内生真菌。对其内转录间隔区（ITS，Internal Transcribed Spacer）序列进行分析后发现：源自健康组织的菌株LBVM Ba.0001与LBVM Ba.0006，分别与裂叶新萨托菌（Neosartorya laciniosa，登录号FR733875.1）、阿斯尤特塔宾曲霉（Talaromyces assiutensis，登录号KM458833.1）具有99%和100%的同源性。从显症组织分离得到的菌株LBVM Ba.0002与LBVM Ba.0003，与茄病镰孢菌（Fusarium solani，登录号KT366735.1）的同源性均为99%；而菌株LBVM Ba.0005则与茄赤壳菌（Nectria haematococca，登录号AY310442.1）具有100%的同源性。研究人员采用对峙培养试验（dual culture assays），对菌株LBVM Ba.0001与LBVM Ba.0006抑制茄病镰孢菌生长的能力进行了检测。结果显示，在离体培养条件下，这两株内生真菌均可显著抑制茄病镰孢菌的生长（P ≤ 0.05）。相较于阿斯尤特塔宾曲霉（IC₅₀ = 0.8 g/L，IC₉₀ = 7.6 g/L），裂叶新萨托菌对茄病镰孢菌展现出最优的生防效果（IC₅₀ = 0.8 g/L，IC₉₀ = 7.6 g/L）。