Evaluation of the susceptibility to Sclerotinia sclerotiorum in four micorryzed bean (Phaseolus vulgaris L.) genotypes

Abstract

The effect of mycorrhizal colonization on reducing susceptibility to Sclerotinia sclerotiorum was investigated in four common bean genotypes: Azufrado Regional 87 (Az Reg 87), Azufrado Higuera (Az Hig), A-55, and BAT 93 using the ‘straw test’ method. Colonization by the arbuscular mycorrhizal fungi Rhizophagus irregularis (formerly known as Glomus intraradices) reduced susceptibility to S. sclerotiorum in A-55, Az Reg 87 and BAT 93 plants, but not in Az Hig. These results provide additional evidence of the existence of a mechanism that reduces susceptibility by mycorrhiza colonization against foliar pathogens, and suggest that mycorrhizal colonization should be considered in breeding programs for S. sclerotiorum resistance.