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

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