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Fusarium oxysporum Schlecht. f.sp. melongenae (FOM), Verticillium dahliae (Ve) and Ralstonia solanacearum are major limiting pathogens affecting eggplant cultivation and their yield in the world. Natural resistance genes are the most environmentally friendly method to control the disease. Thus, marker-assisted selection (MAS) is preferred as a tool for screening resistance genes (R-genes) in eggplant resistance breeding. In this study, markers that are specifically linked to major disease resistance genes conferring resistance to F. melongenae, V. dahliae and R. solanacearum were tested in a population containing breeding materials to validate the resistance. Resistant Solanum melongena accessions LS1934 and LS2436 and their reciprocal crosses were used as the resistance resource for this validation study. Moreover, classical resistance tests to FOM and Ve were performed with the root-dip inoculation method for classification of all the accessions based on their resistance/susceptibility responses. The SCAR426, CAPs_903 and SIVR844 markers were highly informative for the determination of resistance genes (Fomg, Ve and ERs1). Therefore, in areas with high susceptibility to diseases, a highly efficient combination of the relevant R-genes and their pyramiding into commercial eggplant varieties are proposed to be implemented as a pragmatic approach.

Clavibacter michiganensis subsp. michiganensis (Cmm) is one of the phytopathogenic bacteria causing bacterial wilt disease and severe yield losses in tomatoes and other solanaceous vegetables. Although there are some reports on Cmm infections in eggplants (Solanum melongena), there is no information available on the resistance sources and genetic control of the resistance to Cmm in this crop. We performed a search for resistance sources to Cmm in eggplants, in a set of 46 genotypes including landraces, inbred lines and cultivars and some cultivated and wild relatives, as well as an analysis of the genetic control of the resistance. A mixture of different Cmm strains from different genomic groups was used for the screening. Plants were inoculated through the injection of 10 µL of a Cmm suspension at a concentration of 107 cfu/mL in a single point of the stem. The symptoms were recorded at nine weeks after the inoculation with a 0-4 symptoms scale. The differences were observed in the symptoms in the collection evaluated, with the disease severity index of the genotypes ranging from 0.00 to 4.00. While 31 genotypes displayed no symptoms, three cultivated eggplant genotypes were highly susceptible. Reciprocal F1 and F2 generations were obtained from the crosses between the most susceptible genotype (CT30) and a resistant one (CT49). The genetic control of the resistance adjusted well to one dominant and one recessive gene model underlying the resistance to Cmm. These results are important for selection and breeding for resistance to Cmm in eggplants.