Identification of Biocontrol Strain YB-366 and Its Control Effect against Plant-Parasitic Nematodes

CHAI Qiuyuan; ZHANG Jie; LI Xiaoqiang; SONG Yajing; XIA Mingcong; SUN Runhong; XU Wen; WU Chao; YANG Lirong

doi:10.15933/j.cnki.1004-3268.2025.06.010

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.