Bioprospecting the fungicides compatible Trichoderma asperellum isolate effective against multiple plant pathogens in vitro

Abstract

Aim: To isolate Trichoderma spp. from diseased plant tissues and evaluate its suitability as biocontrol agent and its compatibility with fungicides. It is essential to develop an efficient ecofriendly disease management programme which helps in gradual reduction in use of harmful chemicals. The objectives of the study: to isolate, purify and identify Trichoderma isolate from diseased plant tissues and to identify the its compatibility with commonly used fungicides for the eco-friendly management of vegetable diseases. Methodology: Trichoderma asperellum was isolated from Sclerotinia sclerotiorum infected stem tissues of pea on potato dextrose agar. The morphological, cultural characteristics and molecular identification of Trichoderma asperellum was carried out using ITS primers. In vitro antagonistic efficiency of Trichoderma asperellum was studied against phytopathogenic fungi viz., Pythium aphanidermatum, Pythium debaryanum, Sclerotium rolfsii Sr1, Sclerotium rolfsii Sr3, Fusarium oxysporum f.sp. lycopersici and Alternaria solani. Results: The nucleotide sequence of amplified ITS region was deposited at Genbank (NCBI) with accession no. KT824429. The highest mycelial inhibition values of 43.57, 38.16, 42.56 and 54.87% were obtained for Pythium aphanidermatum, P. debaryanum, Sclerotium rolfsii Sr1 and Sclerotium rolfsii Sr3 respectively, after 6 d of T. asperellum inoculation. T. asperellum exhibited 100% compatibility with Mancozeb, Azoxystrobin, Cymoxinil+Mancozeb, Metalxyl+Mancozeb at 100, 200 and 300 ppm. The per cent compatibility of 98.15, 74.82 and 50.38 with Carbendazim at 100, 200 and 300 ppm concentrations was also recorded. Interpretation: These studies established the aggressive nature of the isolate and its suitability in integrated disease management practices.