Systemic resistance induced by Trichoderma harzianum RU01 against Uromyces appendiculatus on Phaseolus vulgaris

Abstract

Trichoderma spp. are effective biocontrol agents for a number of soil-borne plant pathogens. Some isolates are also known for their ability to induce systemic resistance in plants against different foliar pathogens. Induction of systemic resistance against Uromyces appendiculatus, the causal agent of bean rust, by Trichoderma spp. has not been reported. T. harzianum RU01 consistently triggered a significant (P=0.05) degree of protection against rust in bean (Phaseolus vulgaris cv. Keppetipola Nill) under greenhouse conditions. Control efficacy was similar to that of rhizobacterium, Pseudomonas aeruginosa KMPCH, a test strain included in this study, which previously demonstrated induction of systemic resistance in bean. Given the spatial separation of challenging pathogen and biocontrol agent, this effect can be attributed to the induction of systemic resistance by T. harzianum RU01.