RELATION BETWEEN FUSARIUM WILT DISEASE AND ACCUMULATION OF PHENOLIC COMPOUNDS WITHIN RESISTANT AND SUSCEPTIBLE TOMATO CULTIVARS

Wilting disease of tomato caused by Fusarium oxysporum f. sp. lycopersici, (FOL) is one of the most destructive diseases. This disease causes significant yield losses in Egypt. Ten Fusarium isolates were isolated from wilted tomato plants growing in El-Menoufia Governorate during 2020 growing season. The most virulent isolate (isolate No. 6) was tested for its virulence on ten tomato cultivars under greenhouse conditions. The cultivars were significantly varied in their susceptibility toward the tested virulent isolate. The most susceptible cultivar was Carmen F1cv as it recorded the highest value of infection (100% and 96%) in seeds and seedlings experiments, respectively. On the other hand the results showed that Diamond Arwa cultivar was the most resistant tested cultivar where zero infection percentage was recorded on both seeds and seedling experiments. The chemical analysis using HPLC was conducted with the most susceptible tomato cultivar (Carmen) and the most resistant one (Diamond Arwa) one and three weeks post inoculation with pathogenic isolate of Fusarium. The results revealed that the accumulation of total phenolic compounds either in shoots or roots was higher three weeks after inoculation than one week post inoculation within the two tested cultivars. Remarkable that roots and shoots of most resistant cultivar tested recorded more total phenol concentrations rather than the susceptible one. Significant differences were detected among the resistant and the susceptible cultivars tested with the compounds detected at 21.2m; 26,2m and 29.1 minute in both shoots and roots three weeks after pathogen inoculation which suggesting potential role of these particular chemicals in resistance mechanism toward Fusarium wilt disease within resistant tomato cultivars.