Abstract

IN VITRO SCREENING OF ANTAGONISTIC ACTIVITY OF FUNGAL BIOCONTROL AGENTS FOR THE MANAGEMENT OF MACROPHOMINA PHASEOLINA (TASSI) GOID IN COLEUS FORSKHOLII BRIQ

*Lily Trivedi and Pravin Chandra Trivedi

Abstract

Macrophomina phaseolina (Tassi) Goid, isolated from diseased plants of Coleus forskohlii Briq in vivo, was evaluated by dual culture against antagonist fungal spp. Isolated from the rhizosphere of native fields of Rajasthan. All the 11 biocontrol fungi consisting of 9 Trichoderma sp. and Gliocladium virens and Paecilomyces significantly inhibited growth of Macrophomina phaseolina in dual culture experiments. The inhibiton ranged from 70-77% whereas other biocontrol fungi also showed good efficacy. Different isolates showed varying degrees of antagonism. Maximum growth inhibition of the test pathogen was caused by Trichoderma harzianum (T-2) and Trichoderma hamatum (T-8) followed by Trichoderma aureoviride (T-7) and Trichoderma viride(commercial) (T-11). The growth inhibition of Trichoderma spp. can be attributed to all the three modes of antagonism in vitro viz. competition, antibiosis and mycoparasitism.

Keywords: Macrophomina phaseolina (Tassi) Goid, dual culture, biocontrol fungi, Coleus forskohlii Briq.