International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.
Department of Agricultural Science and Technology, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya.
Sci Rep. 2024 Jul 4;14(1):15365. doi: 10.1038/s41598-024-66101-1.
Endophytic fungal-based biopesticides are sustainable and ecologically-friendly biocontrol agents of several pests and diseases. However, their potential in managing tomato fusarium wilt disease (FWD) remains unexploited. This study therefore evaluated effectiveness of nine fungal isolates against tomato fusarium wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL) in vitro using dual culture and co-culture assays. The efficacy of three potent endophytes that inhibited the pathogen in vitro was assessed against FWD incidence, severity, and ability to enhance growth and yield of tomatoes in planta. The ability of endophytically-colonized tomato (Solanum lycopersicum L.) plants to systemically defend themselves upon exposure to FOL were also assessed through defence genes expression using qPCR. In vitro assays showed that endophytes inhibited and suppressed FOL mycelial growth better than entomopathogenic fungi (EPF). Endophytes Trichoderma asperellum M2RT4, Hypocrea lixii F3ST1, Trichoderma harzianum KF2R41, and Trichoderma atroviride ICIPE 710 had the highest (68.84-99.61%) suppression and FOL radial growth inhibition rates compared to EPF which exhibited lowest (27.05-40.63%) inhibition rates. Endophytes T. asperellum M2RT4, H. lixii F3ST1 and T. harzianum KF2R41 colonized all tomato plant parts. During the in planta experiment, endophytically-colonized and FOL-infected tomato plants showed significant reduction of FWD incidence and severity compared to non-inoculated plants. In addition, these endophytes contributed to improved growth promotion parameters and yield. Moreover, there was significantly higher expression of tomato defence genes in T. asperellum M2RT4 colonized than in un-inoculated tomato plants. These findings demonstrated that H. lixii F3ST1 and T. asperellum M2RT4 are effective biocontrol agents against FWD and could sustainably mitigate tomato yield losses associated with fusarium wilt.
内生真菌生物农药是几种病虫害可持续且生态友好型的生物防治剂。然而，它们在防治番茄枯萎病（FWD）方面的潜力尚未得到开发。因此，本研究采用双重培养和共培养试验，评估了 9 种真菌分离物对番茄枯萎病原菌尖孢镰刀菌番茄专化型（FOL）的体外防治效果。评估了三种在体外抑制病原菌的有效内生菌对 FWD 发病率、严重程度以及在植物体内增强番茄生长和产量的能力。还通过 qPCR 评估了内生定殖番茄（Solanum lycopersicum L.）植物在暴露于 FOL 时系统防御自身的能力。体外试验表明，内生真菌对 FOL 菌丝生长的抑制和抑制作用优于昆虫病原真菌（EPF）。内生真菌 Aspergillus terreus M2RT4、Hypocrea lixii F3ST1、Trichoderma harzianum KF2R41 和 Trichoderma atroviride ICIPE 710 对 FOL 的抑制和抑制率最高（68.84-99.61%），而 EPF 的抑制率最低（27.05-40.63%）。内生真菌 T. asperellum M2RT4、H. lixii F3ST1 和 T. harzianum KF2R41 能定殖番茄的所有植物部分。在体内试验中，与未接种的植株相比，内生定殖和 FOL 感染的番茄植株的 FWD 发病率和严重度显著降低。此外，这些内生菌有助于提高生长促进参数和产量。此外，T. asperellum M2RT4 定殖的番茄防御基因表达显著高于未接种的番茄植株。这些发现表明，H. lixii F3ST1 和 T. asperellum M2RT4 是防治 FWD 的有效生物防治剂，可以可持续地减轻与枯萎病相关的番茄产量损失。
