Fusarium oxysporum f. sp. lycopersici (Fol) is a soil-borne plant pathogen that causes wilt in tomato (Lycopersicon esculentum L.) and also incurs economic losses threatening tomato industry worldwide. The interaction between tomato and Fol has become a model system for the study of the histological basis of disease resistance and susceptibility in plants. Therefore, in the present study the host pathogen interactions of Fol on tomato during the wilt infestation and in vitro antifungal assay of Cissus quadrangularis in minimizing the pathogen growth was studied to generate remedies to prevent the disease for the benefit of farming community. During the study it was observed that 80% concentration of Cissus quadrangularis plant extract has significantly suppressed the fungal colony growth (16.2mm) followed by the 60% concentration of the plant extract (13.1mm). However, lower concentration of plant extracts (20 & 40%) has exhibited their inability in suppressing the fungal growth. The in vivo studies on fungal spore suspension inoculation to normal seedling of T1 (no plant extract treatment) and treated with plant extract (T2) and T3 of resistant (INDEX-300) seedlings showed minimal host pathogen interaction compared to normal seeds (T1) indicating that plant extract has induced resistance in T2 & T3 seedling to the Fol inoculation. The above results clearly indicated that plant extract of Cissus quadrangularis can be used as biological control agent (botanical extra) for suppressing and minimizing the tomato wilt disease.
