ASSESSMENT OF OOMYCETES FUNGI IMPACTING INDIAN TOMATO FIELDS: DAMPING OFF AND LATE BLIGHT PERSPECTIVES.

The Oomycetes fungi, known as water molds are a group of numerous hundred microorganisms that comprise certain of the most disturbing phytopathogens. They can cause damping-off, seedling blights, foliar blights, downy mildew and root rots. Tomato (Lycopersicon esculentum) is an economically and nutritionally important species grown worldwide. Late blight and damping off are two major diseases, which are caused by oomycetes. The present study collected infected samples of tomatoes from four geographic locations in Karnataka, India and identified the pathogens through morphological and molecular methods. Ten different fungal species were identified through microscopic study, with dominance of Pythium and Phytophthora species at all locations. Molecular characterization through ITS sequences and phylogenetic analysis confirmed the presence of two oomycetes Pythium aphanidermatum and Phytophthora infestans. ITS sequences of these two fungi were deposited at NCBI with accession numbers OR677915 and OR677916, respectively. Experimental inoculation of Pythium aphanidermatum (20ml Inoculum/litre) in soil having 20-day-old tomato plants resulted in the 100% yellowing, wilting, collapse, and death of plants within 7 days of inoculation. Inoculation of Phytophthora infestans (20ml Inoculum/litre) was sprayed on fruiting tomato plants resulting in black/brown lesions followed by up to 80% wilting of leaves and fruits within 7 days of spray. This research contributes to our understanding of fungal diseases affecting tomato crops in Karnataka, India and provides a foundation for future studies aimed at developing sustainable disease management practices. [ABSTRACT FROM AUTHOR]