Prevalence of Fusarium spp. causing wilt in chickpea and its cultural and morphological characterization

Abstract:

Chickpea (Cicer arietinum L.) is a major pulse crop in India, valued for its high nutritional content, but it is severely affected by wilt disease caused by Fusarium spp. The present study was conducted to assess the incidence, isolation, pathogenicity and variability of the wilt pathogen in major chickpea-growing areas of Junagadh district, Gujarat, during Rabi 2023-24 and 2024-25. A roving survey covering six talukas revealed that wilt disease was prevalent in all surveyed locations, with mean disease incidence ranging from 16.45 to 22.09 per cent. The highest incidence was recorded in Mendarda (22.09%), followed by Bhesan (20.45%), while the lowest was observed in Junagadh (16.45%). At the village level, disease incidence varied widely, ranging from 4.35 to 37.08 per cent, indicating significant spatial variability.A total fourteen isolates of Fusarium spp. were obtained from infected plants and evaluated for pathogenicity on susceptible chickpea cultivar JG-62. All isolates were pathogenic, exhibiting disease incidence between 50.00 and 100.00 per cent. Among them, isolates FOC-4 and FOC-11 were highly virulent, causing 100 per cent wilt incidence, whereas FOC-8 and FOC-13 showed comparatively lower virulence (50.00%). Considerable variability was observed among isolates in terms of cultural and morphological characteristics. Colony diameter ranged from 80.07 to 87.87 mm, with FOC-8 showing maximum growth. Differences were also recorded in colony colour, texture, margin and sporulation. Morphologically, microconidia were hyaline, oval to elliptical and mostly unicellular, while macroconidia were hyaline, falcate and multi-septate. Chlamydospore formation varied among isolates, indicating heterogeneity within the pathogen population.