Diversity of Molecular Factors of Resistance to Bacterial Wilt (Ralstonia solanacearum) in Eggplant

The Ralstonia solanacearum species complex (RSSC) causes the bacterial wilt (BW) on a wide range of hosts including Solanaceae crops such as eggplant. BW is a major disease in tropical and subtropical areas. Varietal resistance is considered the most effective way to sustainably control the BW at a reasonable cost. We studied a double haploid (DH) population of 207 lines, obtained from F1 hybrids [MM1800 x MM738]. The parent S.melongena MM1800 is a resistant S. melongena line created by the AVRDC (Asian Vegetable Research Development Center, Taiwan). MM1800 is resistant to a large range of RSSC strains in particular to phylotype I and IIB-1 strains (Lebeau et al., 2011) . The parent MM738 (susceptible), is a French S. melongena line created by INRAe (Institut National de Recherche pour l'Agriculture, l'alimentation et l'Environnement, France).The DH population and controls were infected with the most prevalent strains of RSSC, phylotype I-31 in summer and II-B1 in winter, using the irrigation inoculation method.  Genetic data from an DH population were analyzed using Stacks and  a high-density map was developed with 2,846 genotyping-by-sequencing (GBS)-generated single nucleotide polymorphism (SNP) markers using 187 DH progenies from F1 hybrids [MM1800 x MM738]. This analysis will allow us to identify QTLs associated with resistance. This study should provide a useful resource for marker-assisted selection already in place for two Reunion Island eggplant varieties.