Summary: Coniothurium minitans (CM) is hyperparasitic to Sclerotinia sderotiorum (55), a palhogen of many economically important crops. In this paper, we describe lhe isolation of improved mutants of CM, using a UV - irradiation regime, with altered chitinase production and tolerance to high concentration of iprodione, which are effect:iveagainst Ss. Three out of the 59 mutants obtained inhibited the mycelial growth of CM. Infectivity of sclerotia by the new mutants was assayed by the plant-tissue-based system using carrot segments. More than 80%of sclerotia were colonized by lhe mutants and the wild-type CM. The mutant strains retained ability to produce significant amounts of chitinase. The mutants differed frorn their wild-type strain in appearance, morphology and sporulation. In conclusion, the results presented here provide evidence that lhe new biotypes of C. minitans are effective in controlling S.sclemtiarum.

Publication year: 2011

Types of publication: Journal article

Unit: Embrapa Environment