The parental, F1, F2, Bc1 and Bc2 generations of the three interspecific crosses Super – Marmande X LA1375, Edkawi X LA1375 and UC.97-3 X LA1375 were evaluated in field and greenhouse to study the inheritance and nature of resistance to fusarium wilt disease. Resistance to fusarium wilt disease was found to be controlled by one dominant gene. The ratio of resistance to susceptibility in the F2 hybrid and the Bc1 hybrid(from a backcross to the susceptible parent) populations was 3 : 1 and 1: 1, respectively. The results showed that the earliness and fruit weight were inherited quantitatively. The nature of dominance for some components of resistance to fusarium wilt disease of tomato ranged from partial dominance to over dominance in the different interspcific crosses. The Broad sense heritability estimates ranged from 52.59% to 73.33% and from 56.90% to 84.15%, Meanwhile the narrow sense heritability ranged from 31.11% to 44.28% and from 24.45% to 54.33% for earliness and fruit weight, respectively. The minimum number of effective gene pairs controlling earliness ranged from 1 to 4 and for fruit weight ranged from 2 to 16 gene pairs. Highly significant positive correlations were found between plant reaction to fusarium wilt and each of Reducing, Non – reducing and total sugars. Meanwhile, highly significant negative correlations were observed between plant reaction to fusarium wilt and each of number of branches/plant, number of fruits/plant, fruit weight, total yield/plant and total, free and congested phenols. Highly significant correlation was detected between total yield/plant and some component characters, i.e. resistance to fusarium wilt disease, number of fruits/plant, fruit set percentage, fruit weight, length and diameter. |
