Vol. 10, Issue 5 (2021)

Author(s):
R Jayalakshmi, ST Mehetre, R Kannan, M Paramasivam, VP Santhnakrishnan, KK Kumar and V Ramamoorthy

Abstract:
Tomato is an economically important and commercially worldwide grown crop. Damping off and fungal wilt are the most devastating diseases of tomato which causes considerable damage on yield. The infected samples of tomato were collected from different parts of Tamil Nadu. In the present study, Pythium was isolated from infected collar region of seedling and Fusarium was isolated from discoloured vascular region of tomato stem. The characterization of Pythium and Fusarium was performed based on their morphological characters. The hyaline, non- septate mycelium, oospore and lobed sporangia formation were confirmed the isolates as Pythium aphanidermatum whereas macro conidia, micro conidia and chlamydospores were confirmed the isolates as Fusarium oxysporum f. sp. lycopersici. The pathogenicity test for Pythium and Fusarium isolates were carried out by soil inoculation and stem injection method respectively. The virulent isolates of Pythium and Fusarium were identified by pathogenicity test. Based on symptom expression highly virulent pathogen was identified among the isolates. The Pythium isolate P2 showed disease incidence of 96.67% and Fusarium isolate F3 showed 71.43% disease incidence and both the isolates were identified as highly virulent compared to all other isolates.