Studies on the inheritance of resistance to verticillium wilt in eggplant (solanum melongena L.)

Eggplant has an important role in agricultural production in the world and Turkiye. Turkiye is 4th in eggplant production in the world. There are many biotic stress factors that limit greenhouse eggplant cultivation. Verticillium wilt caused by soil-borne wilt pathogen Verticillium dahliae Kleb., is one of the most important plant diseases that limits production in eggplant production areas of our country. The pathogen can survive in the soil for many years, and when environmental conditions are suitable for the disease, wilting can be observed in the new plant planted the following year. Cultural and chemical methods are used to control the pathogen. However, these methods are not only ineffective against the disease agent but also uneconomical. Cultural control methods applied by producers during cultivation play a role in slowing down the emergence and spread of the disease, but are insufficient in effective control of the disease. For this reason, this situation necessitates studies to develop pathogen-resistant varieties. Breeding programs have been initiated in our country to obtain varieties resistant to Verticillium dahliae, which is an important problem in eggplant cultivation both in the world and in our country. In our study, two different F2 populations were obtained by reciprocal crossbreeding of pure line LS2436 resistant to Verticillium and pure line LS1934. Within the scope of the project, 300 genotypes consisting of LS2436xLS1934 and LS1934xLS2436 hybrid combinations were tested classically and resistant and susceptible individuals were determined. 350 SSR primers were tested for use in QTL mapping studies and a total of 33 primers were found to be polymorphic in the parents. As a result of QTL analyses, it was determined that only one marker was associated with Verticillium resistance at the highest LOD value (LOD = 2.494). For the purpose of developing markers to be used in mapping studies, the parents of the mapping population were sequenced using next-generation sequencing technology and a total of 1,039,550 polymorphic SNPs were found among the parents. In addition to these SNP markers, 221,764 InDel markers were also developed. 4,249 of the InDel markers have at least 30 nucleotide allelic differences between the parents and are suitable for agarose gel electrophoresis analysis. These markers have been physically mapped in the eggplant genome and are distributed homogeneously in the genome. The genome map is high resolution (0.27 Mb/InDel) and the developed markers are a valuable molecular tool for eggplant genomic studies and can be used in Verticillium resistance studies.