ABSTRACT

Meloidogyne incognita, one of the most important root-knot nematodes of crops, is still mainly controlled with synthetic agrochemicals. Toward finding eco-friendly alternative controls such as biocontrol fungi or fungal extracts, here fungi were screened in vitro for nematicidal potential, then evaluated for efficacy against M. incognita in greenhouse tomato plants. Forty fungal extracts were also tested at 300 µg mL⁻¹ against second-stage juveniles of M. incognita. Then the strain that produced the most active extract was added (six treatments, mycelium/conidia) to nematode-infested soil in a pot with tomato plants. Agronomic and reproductive variables were measured after 92 days. The best nematicidal extract was from Clonostachys rosea TH27 (LD₅₀ = 375 µg mL⁻¹), which reduced the number of galls, eggs and females in tomato roots and slightly improved agronomic traits compared with untreated plants. For control of M. incognita in pots in protected conditions, 2 g of inoculum per pot (5 kg) is recommended. Our findings confirmed that C. rosea mycelia has potential for control of M. incognita in tomato plants in the greenhouse.

摘要

南方根结线虫是农作物最重要的根结线虫之一，目前仍主要用合成农药防治。为了寻找生态友好的替代控制措施，如生物防治真菌或真菌提取物，在体外筛选真菌的杀线虫潜力，然后评估其在温室番茄植物中对抗M. incognita 的功效。还针对M. incognita 的第二阶段幼虫以 300 µg mL ^-1测试了 40 种真菌提取物。然后将产生最活跃提取物的菌株（六种处理，菌丝体/分生孢子）添加到盛有番茄植物的盆中线虫侵染的土壤中。92 天后测量农艺和繁殖变量。最好的杀线虫提取物来自Clonostachys rosea TH27 (LD ₅₀  = 375 µg mL ^-1 )，与未经处理的植物相比，它减少了番茄根中瘿、卵和雌性的数量，并略微改善了农艺性状。为了在受保护的条件下控制盆中的南方根结线虫，建议每盆 (5 kg) 接种 2 克接种物。我们的研究结果证实，C. rosea菌丝体具有控制温室番茄植株中南方根结线虫的潜力。