捕食线虫性真菌Duddingtonia flagrans DF-shz3株的分离鉴定及其捕食活性与产孢特性研究OA

This study aimed to isolate a nematode-trapping fungal strain with high predatory activity and strong sporulation capacity,providing a candidate microorganism for the development of biocontrol a-gents against nematode infections in herbivorous animals.Soil samples were collected from the Tianshan Pasture in Xinjiang,China,and screened for nematode-trapping fungi.The isolated strains were identified based on morphological characteristics and molecular phylogenetic analysis.Their predatory efficiency and sporulation traits were also evaluated.A single strain,designated DF-shz3,was successfully isolated.The colony appeared white,with septate and branched hyphae,and produced abundant chlamydospores and a small number of conidia.The chlamydospores were globose with spherical surface ornamentations,while the conidia were pyriform or ovoid with a single septum located centrally.Phylogenetic analysis based on the ITS sequence revealed 100％homology between strain DF-shz3 and Duddingtonia flagrans,clustering with the reference sequence KP257593.1.Both morphological and molecular evidence confirmed that DF-shz3 belongs to Duddingtonia flagrans.Strain DF-shz3 exhibited a high predation rate of 97.93％against third-stage larvae of Caenorhabditis elegans,forming adhesive networks as its trapping structure.When cultured on YPSSA medium at 30℃ for 28 days,DF-shz3 produced the highest yield of chlamydospores.In this study,a strain of the nematode-trapping fungus Duddingtonia flagrans suitable for the prevention and control of nematodiasis in native herbivorous animals in Xinjiang was isolated.