Biological control of Sclerotinia sclerotiorum (oilseed rape isolate) by an effective antagonist Streptomyces

Abstract

Sclerotinia sclerotiorum (Lib) De Bary, the causal agent of stem rot of oilseed rape, is one of the most important phytopathogens. In order to find appropriate biocontrol agents, antagonistic and especially chitinolytical activities of 110 soil actinomycetes were examined. Among assayed isolates, Streptomyces sp. isolate 422 significantly reduced (P ≤ 0.01) the incidence of disease. Biological and physiological analysis of this isolate shown that, its active metabolite had polar nature, long shelf life and fungicidal activity features. Moreover, a partial chitinase (600 bp) gene was cloned and sequenced. This study has tried to introduce an effective biocontrol agent against S. sclerotiorum with a broad spectrum of antagonistic activity against phytopathogens.

Key words: Biocontrol, Brassica napus L. ssp. Oleifera, Sclerotinia sclerotiorum, streptomycetes.