Inheritance of resistance to Ralstonia pseudosolanacerum in the tomato genotypes Yoshimatsu and Hawaii 7996

Abstract The aim of this study was to study the inheritance of resistance to Ralstonia pseudosolanacearum in the tomato genotypes Yoshimatsu and Hawaii 7996 and to determine whether the resistance loci governing this trait in these genotypes are the same. The Yoshimatsu and Hawaii 7996 genotypes and the F1, F2, BC11 and BC21 generations were evaluated in one experiment, and 60 F2:3 progenies were evaluated in a second experiment. The severity of bacterial wilt was assessed using a descriptive scale of scores at 20 days after inoculation. In the Yoshimatsu genotype, the inheritance of resistance to R. pseudosolanacearum is governed by two major genes involved in recessive homozygosity. In the Hawaii 7996 genotype, the inheritance of R. psedosolanacearum resistance is governed by a gene with partial dominance. The greatest contribution of gene effects was due to additive variance. For R. psedosolanacearum, it is recommended that F2:3 progenies be selected 20 days after inoculation and within. Significance of this study What is already known on this subject? Bacterial wilt caused by Ralstonia species, especially Ralstonia pseudosolanacearum, causes significant losses in peppers of the genus Capsicum and also in tomatoes (Solanum lycopersicum) under conditions of high temperature and humidity. Its control is difficult due to the high capacity of the pathogen to remain in the soil for many years associated with the rhizosphere of a large number of host species. Obtaining resistant cultivars is therefore of great value for controlling the disease. What are the new findings? We found that in the Yoshimatsu genotype, the inheritance of resistance to bacterial wilt is governed by two genes in homozygous recessive traits, whereas in the Hawaii 7996 genotype, the inheritance of resistance to bacterial wilt is governed by one gene with partial dominance. The major contribution of genetic effects was due to additive variance. Therefore, it is recommended that F2:3 progenies be selected 20 days after inoculation. What are the expected impacts on horticulture? It is hoped that, with the continuation of our tomato breeding programme, we will obtain a new cultivar that is highly resistant to bacterial wilt and thus contribute to a more sustainable and economically viable crop.