Abstract: Plant‐parasitic nematodes severely threaten global agricultural production security.To explore superior biocontrol strains against plant‐parasitic nematodes，this study evaluated the biocontrol potential of a nematophagous fungal strain YB‐366 against wheat cyst nematode disease（Heterodera filipjevi）and vegetable root‐knot nematode disease（Meloidogyne incognita）. Firstly，the in vitro determination method was used to assess the lethal effects of YB‐366 fermentation filtrate on second‐stage juveniles of H.filipjevi and M.incognita，as well as its inhibition on egg hatching. Further pot experiments and field trials were conducted to verify the control efficacy of YB‐366 against these two nematode diseases.Morphological characterization and molecular identification were subsequently performed to determine the taxonomic status of strain YB‐366. Results showed that the fermentation filtrate caused corrected mortality rates of 95.6% and 93.5% for H.filipjevi and M.incognita J2 larvae within 48 h，respectively，and significantly inhibited egg hatching with suppression rates of 81.6% and 78.5%.In indoor and field trials，soil treatment with YB‐366 wheat bran‐sand culture reduced cyst number in wheat by 60.5% and 55.2%，respectively，and achieved control efficiencies of 60.7% and 58.9% against vegetable root‐knot nematodes. Additionally，the treatment markedly promoted the growth of wheat and tomato plants.Based on morphological and molecular identification，YB‐366 was classified as Chaetomium megalocarpum.Overall，C.megalocarpum strain YB‐366 demonstrates substantial potential for development and utilization in biocontrol agent research and formulation development，as well as the establishment of green pest management systems for sustainable agriculture.

Key words: Chaetomium megalocarpum, Heteradera filipjevi, Meloidogyne incognita, Biological control

摘要： 植物寄生线虫在全球范围内对农作物的生产安全构成严重威胁。为挖掘优良的植物寄生线虫生防菌株，对分离到的一株线虫生防真菌YB-366进行小麦孢囊线虫病和果蔬根结线虫病的生防潜力评估。首先通过离体测定方法测定YB-366菌株发酵滤液对菲利普孢囊线虫（Heteradera filipjevi）和南方根结线虫（Meloidogyne incognita）二龄幼虫的致死作用及其卵孵化的抑制作用，进一步利用盆栽试验和田间试验验证YB-366菌株对小麦孢囊线虫病和果蔬根结线虫病的防治效果，并通过形态学和分子生物学方法对YB-366菌株进行鉴定。结果显示，YB-366菌株发酵滤液对菲利普孢囊线虫和南方根结线虫的二龄幼虫均表现出较强的致死作用，48 h校正死亡率分别高达95.6%、93.5%，且有效抑制了2种线虫卵的孵化，孵化抑制率分别为81.6%、78.5%。室内和田间防效试验中，YB-366麦粒砂培养物土壤处理对小麦孢囊线虫病的孢囊减退率分别为60.5%和55.2%，对果蔬根结线虫病的防治效果分别为60.7%和58.9%，同时显著促进了小麦和番茄植株的生长。通过形态学和分子生物学方法将YB-366鉴定为大果毛壳菌（Chaetomium megalocarpum）。综上所述，大果毛壳菌YB-366菌株在生物防治制剂研发、绿色防控体系构建中具有较好的开发利用潜力。

关键词: 大果毛壳菌, 菲利普孢囊线虫, 南方根结线虫, 生物防治