Assessment of Susceptibility to Downy Mildew Disease in Some Grape Varieties and Genotypes Using Marker-Assisted Selection

The leaves of the vine plant, like its fruits, are used in human nutrition and meals in many countries. Grape leaves serve as an important ingredient in traditional foods. In Türkiye, the leaves of Narince, Sultani Çekirdeksiz and Yapıncak grape varieties are preferred for stuffed grape leaf production. However, pesticide residues generate a serious problem for brined vine leaves. Fungicides with different active ingredients are used to combat downy mildew and powdery mildew diseases in viticulture. Improper use of these chemicals results in serious residue problems on product surfaces. Such cases pose serious threats to human health and the environment. This study used the marker-Assisted Selection (MAS) method to identify individuals containing genes resistant to Plasmopara viticola in grape genotypes obtained through hybridization. The presence of the Rpv3 gene in hybrid individuals was examined. Total nucleic acids were extracted from fresh leaves of the plants, and the regions related to the Rpv3 gene were amplified on the genomic DNA with GF18-06/GF18-08 primers. PCR products were visualized using an agarose gel electrophoresis system, and allele gene sizes were also determined by fragment analysis. MAS method yielded 27 genotypes with the Rpv3 gene. DNA sizes were also confirmed by fragment analysis. The promising genotypes were selected for future studies.