Interspecific Hybridization between Cherry (Small Fry) Tomato and Petomech for Resistance to Root-Knot Nematodes (Meloidogyne Species)

Abstract

Root-knot nematode, (Meloidogyne spp) is one of the important plant parasitic nematodes of tomato worldwide. The high cost of resources involved in controlling diseases and pests in vegetable crop production, the impact of agro-chemicals on the environment and human health has made the use of resistant or tolerant cultivars the most appropriate control technique of plant parasitic nematodes. This study looked at producing nematode resistant tomato variety. Two pot experiments and a field work were carried out separately at Kwame Nkrunmah University of Science and Technology (KNUST) and Crops Research Institute (CRI), KWADASO. This was done to identify resistant tomato genotypes and incorporate in breeding for root knot nematode resistance. The pot experiments were laid out in a completely randomized design. Crosses were however, done on the field and this was between Petomech (susceptible variety) and Small Fry (resistant variety). The heaviest fresh root weight was found in Petomech 7.9g.Tomato genotypes Small Fry and the F₂ obtained the least weights of 3.3g and 3.6g respectively. Petomech recorded the highest mean number of eggs (53.6). The mean number of juveniles recovered from the roots of the three tomato genotypes ranged from 18.6 to 33.6. Petomech recorded the highest number of juveniles which was significantly different from Small Fry and F_2.Moreover, Petomech was significantly different from Small Fry and F₂ regarding reproduction factor. Nevertheless there was no significant difference between Small Fry and F_2.The study established that a total of 1500 eggs/tomato plant was found as the optimum initial inoculum level for screening for resistance in tomato to Meloidogyne spp. The F₂ genotype with gall index (GI) >2 and reproduction factor (R_f)(1.12) was moderately resistant to root-knot nematodes with good horticultural attributes.