Heterosis for Yield Components and Fruit Traits in Tomato under Condition of Fusarium Infection and Biological Control by Antagonistic Bacteria

This study aimed to induce hybrid genotypes resistant to fusarium wilt disease in tomato, as well as using Bacillus thuringiensis as a biological control agent against Fusarium oxysporum. Four tomato varieties were used in this study to induce 12 F1 hybrids and their reciprocal hybrids via diallel crosses. High significant heterosis relative to the mid-parent was obtained with the largest value by P1×P2 for plant height, in addition to significant heterosis was obtained by the reciprocal hybrid for the same trait in fungi and control treatments. The parental variety P3 had the highest mean values of total yield per plant in the four treatments where the bacterial treatment T4 gave the highest mean value of total yield per plant in relation to other treatments. The reciprocal hybrid P3×P1 gave the highest mean values in the four treatments for the total weight of fruits per plant which referred to the maternal effect. The hybrid P2×P3 gave highly significant values of  heterosis in the four treatments for weight of three early collections and total weight of fruits per plant. The results appeared that Bt treatments enhanced all traits measured in this study especially chemical parameters. This indicated that Bt played a major role in the control of natural infection due to biotic stress. In addition, tomato showed higher heterosis in crosses and reciprocal crosses which depends on the distance between varieties.