Fusarium wilt of tomato caused by Fusarium oxysporum f sp. Lycopersici, is an economically important disease in greenhouse and field conditions. The fungi invade plants vascular tissues and induce severe wilting of the foliage by blocking xylem transport and impeding the movement of water. The primary control strategy consists of breeding wilt-resistant cultivars. In this research an experiment was designed to find potential sources of resistance under glasshouse condition in Iran during 2005-2006. Three isolates of fungi and 121 tomatoes lines and hybrids were used. Three week old plants with 2-4 true leaves were inoculated by dipping the roots in a freshly prepared inoculum (1 x 106 spores/ml) for 10 minute. Control plants were treated with water. After 30 days inoculated plants were evaluated based on Grattidge and O'Brien (1982): leaf disease index, Plant high and vascular discoloration. Numerical data of the experiment was statistically processed by program of MSTATC. The reaction of the 121 lines and hybrids of tomato to F. oxysporum.f sp. Lycopersici (race 1) indicated that 21 were nearly immune, 65 resistant, 15 tolerant and the others were susceptible (Banerjee et al., 1990). The new sources of resistance described in the present study offer new genetic material for breeding programs for resistance to Fusarium wilt in tomato.
