Isolation and identification of an entomopathogenic fungus isolated from the pupae of Apocheima cinerarius

Abstract:

[Objective] Some naturally diseased Apocheima cinerarius pupae were collected in poplar forests in Hongtong, Shanxi province, China. The strain of YHT01 was isolated and purified from these naturally diseased pupae, and its classification status was determined. [Methods] A. cinerarius inoculation was conducted with conidial suspension (1.0×108 conidia/mL) of strain YHT01. The morphological characteristic was observed using scanning electron microscopy and the molecular identification was conducted by ITS sequence determination and phylogenetic analysis. [Results] White mycelia emerged between body segments after inoculated by strain YHT01. The colonies of the strain in PDA culture medium showed oval shape, white and fluffy, while the back of the colonies showed orange yellow. The coremium of the strain were like brooms, and the conidium was small (2.1–3.4) μm×(1.1–1.8) μm, oval to ellipsoid, smooth observed by scanning electron microscope. The comparability between the rDNA-ITS sequence of strain YHT01 and Isaria farinosa (Holm: Fr.) Fr. (AB233337) in Genbank is 99%, and these two strains are gathered in one branch in the phylogenetic tree. [Conclusion] Strain YHT01 is a pathogenic fungus of A. cinerarius, and identified as I. farinosa.

Key words:Apocheima cinerarius, pupae, entomopathogenic fungi, Paecilomyces, Isaria farinosa, strain identification