Isolation of Rosellinia necatrix Mutants with Impaired Cytochalasin E Production and Its Pathogenicity.

Abstract

Cytochalasin E ( CE ) is known to be a secondary metabolite secreted in vitro by Rosellinia the cause of white root rot , and is toxic to plants . In this study , CE was detected in Japanese pear and apple roots infected with R . necatrix using a new HPLC method . In order to elucidate the relationship between the productivity of CE and disease progress , CE deficient mutants of R . necatrix were obtained by UV irradiation . Two CE-less producing mutants were isolated by a simple TLC detection The pathogenicity of these mutant strains was the same as the parent ( wild-type ) these mutant strains produced CE only about 4-7 % level of the parent strain in vitro , and less than 5 % level in planta . The meaning of CE for disease progress of white root rot was discussed .