Isolation,Identification and Predatory Nematode Activity of the Nematophagous Fungus Arthrobotrys conoides
To develop an efficient and broad-spectrum predatory nematode-trapping fungus biocontrol agent,soil samples from pastoral and forest areas in Shihezi area of Xinjiang were collected for the isola-tion and identification of predatory fungi.The purified strain was subjected to 18s rRNA and ITS gene se-quence amplification and phylogenetic analysis,and its predatory nematode activity was determined.Re-sults show the isolated fungal colonies(designated as AC-shz1)exhibited white colonies and colorless hyphae.Its conidia were colorless,erect and septate,with spherical conidia borne at the apex of the conidi-ophores.The conidia were inverted conical in shape,with a septum and lobes at the septum,which is per-fectly consistent with the morphological characteristics of Arthrobotrys conoides.Phylogenetic analysis re-vealed that AC-shz1 isolate had the highest homology(100%)with Conus conifensis and clustered into a clade with OQ398107.1.Assessment of predatory nematode ability showed that the AC-shz1 strain exhibi-ted a predation efficiency of 96.7%against third-stage larvae of Caenorhabditis elegans,using a sticky net as the trapping device.The highest sporulation was observed on corn kernel medium,with a sporulation concentration of 8.33 ×1010·mL-1.These results indicate that the isolated Conespora conifolia strain pos-sesses strong sporulation and nematode-predation activity,laying the foundation for the preliminary re-search of an efficient biocontrol agent.
nematode-trapping fungiisolation and identificationArthrobotrys conoidesmorphologi-cal featuresCaenorhabditis elegans