Characteristics of Double Fungicide Resistant Strains of Venturia inaequalis

Penconazole-resistant and cabendazim-resistant mutants of Venturiu inaequalis were developed by chemical (MNNG) mutagenesis. Protoplasts of these mutants were isolated and fused using polyethylene glycol as the fusogen. Fusants were classified into parental, non-parental and recombinant types. The recombinants were resistant to penconazole and carbendazim. The double resistant strains were stable and exhibited pathogenicity on fungicide-sprayed and unsprayed apple twigs.