Mode of Parasitism of the Antagonist Trichoderma Viride towards the Phytopathogen Alternaria Solani

Abstract

In a previous work, the optimized crude chitinase of Trichoderma viride exhibited strong inhibitory activity against food spoilage moulds (phytopathogens) Alternaria solani, Botrytis cinerea, Penicillium oxalicum and P. italicum, with the first species being the most affected. Currently, on testing the antagonistic activity of T. viride against the previous phytopathogens, the antagonist exhibited a strong activity particularly towards A. solani. The antagonist displayed more than one mechanism of parasitism on A. solani including penetration of the pathogen hyphae, abnormal pathogen hyphae swelling, lack of conidia formation, conidia malformation as well as degradation of the pathogen cell wall chitin through secretion of chitinase enzyme which is a major cause of antagonism. Fortunately, the present chitinase secreted by Trichoderma viride is found to be a constitutive enzyme. The previously optimized enzyme showed also a powerful insecticidal activity against home insects cockroach, spider and ant where the exoskeleton was softened and hydrolyzed, followed by rapid killing of the insects within 12 minutes. Contribution/ Originality: This study is one of very few studies which have investigated the in vitro mode of parasitism of Trichoderma viride on the food spoilage mold A. solani which exhibited more than one mechanism including hyphae penetration, abnormal hyphae swelling, conidia malformation and lysis of the cell wall chitin.