Morphological Characterization of Colletotrichum truncatum from Diverse Agro-climatic Zones of Madhya Pradesh, India

Abstract

Anthracnose caused by Colletotrichum truncatum is a major constraint in soybean production, affecting leaves, stems, pods, and seeds. In the present study, ten isolates of C. truncatum were collected from ten locations across nine districts and seven agro-climatic zones of Madhya Pradesh. Their cultural and morphological characteristics were evaluated on five different media: Potato Dextrose Agar (PDA), Oatmeal Agar (OMA), Corn Meal Agar (CMA), Czapek’s Dox Agar (CDA) and Richard’s Agar (RA). Colony morphology, mycelial density, sporulation, and radial growth were recorded at 2nd, 5th, 8th, and 11th days post-inoculation. Significant variability was observed among isolates and media in terms of colony texture, colour, mycelial density, and sporulation. PDA supported the fastest early growth and maximum final radial expansion, while OMA and CDA promoted vigorous sporulation. Corn Meal Agar also supported good growth and sporulation for most isolates. Richard’s Agar consistently exhibited the lowest radial growth and sparse sporulation. These findings indicate that PDA, OMA, and CMA are the most suitable media for studying growth and reproductive potential of C. truncatum, and the observed isolate-specific differences highlight considerable intraspecific variability, which may have implications for disease management and inoculum production.