Biological control of Paecilomyces formosus, the causal agent of dieback and canker diseases of pistachio by two strains of Streptomyces misionensis

Publication date: Available online 30 July 2019Source: Biological ControlAuthor(s): Abdollah Torabi, Gholam Hosein Shahidi Bonjar, Roohollah Abdolshahi, Mostafa Pournamdari, Ismail Saadoun, Essaid Ait BarkaAbstractDieback and canker of pistachio shoots and limbs is a commercially significant disease in Iran. Paecilomyces formosus (Sakag., May., Inoue and Tada) Houbraken & Samson is considered as the major causal agent of this malady. Actinomycetes and particularly members of the genus Streptomyces are well known as biocontrol agents for many plant diseases; they achieve this by production of bioactive metabolites and hydrolytic enzymes. The present study aimed to exploit Streptomyces isolates to biologically control P. formosus in vitro and in greenhouse experiments. Fifty two actinomycetes isolates were evaluated for their antagonistic effect against P. formosus isolated from diseased orchards. Considering their in vitro antagonistic performance, two isolates, designated as BH4-1 and BH4-3 were selected for molecular identification and in vivo experiment to be evaluated for biocontrol efficacy. Partial sequences of 16S rDNA unveiled their identity as two strains of Streptomyces misionensis with 99.9% sequence homology. For in vivo greenhouse experiments, inoculation of artificially made wounds on pistachio young trees stems performed with spore suspensions and culture extracts of either of the two bioactive S. misionensis Cercos et al. strains alone and/or together with P. f...
Source: Biological Control - Category: Biology Source Type: research