Morphological and Molecular Characterisation of Fusarium Wilt Pathogen Isolated from Sunhemp
Chandana H S *
Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Nithya S Raju B H
Division of Plant Pathology, College of Agriculture, University of Agricultural Sciences, Dharwad, 580005, Karnataka, India.
Chethan Kumar K B
Division of Plant Genetic Resources, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Veershetty
Division of Agricultural Statistics, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Prajwal S K
Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
Aditya V Machanoor
Division of Water Science and Technology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
*Author to whom correspondence should be addressed.
Abstract
Fusarium wilt, caused by Fusarium oxysporum f. sp. crotalariae (Kulkarni) Subram. is a significant disease affecting sunhemp (Crotalaria juncea) production, leading to substantial yield losses. To understand the pathogen's biology and enhance management strategies, comprehensive investigations were conducted under laboratory and field conditions at the University of Agricultural Sciences, Dharwad, during 2019-20. The pathogen was cultured on various solid media, with Richard’s agar identified as the most conducive for fungal growth, while potato dextrose agar, Czapeck’s dox agar, and Richard’s agar facilitated good sporulation. Notable variation was observed in colony morphology, including color, texture, margin, growth nature, and sporulation across the different media. Molecular characterization confirmed the pathogen as closely related to F. udum, with a 99.79% similarity to an isolate with the GenBank accession number MK575503.1. These findings provide valuable insights into the pathogen's growth characteristics and genetic identity.
Keywords: Crotalaria juncea, Fusarium oxysporum f.sp.crotolariae (Kulkarni) Subram