Improve of new powdery mildew tolerant grape cultivars for stuffed vine leaf

Powdery mildew disease caused by Erysiphe necator is a serious grape vine disease worldwide. The use of resistant or tolerant cultivars to this disease can eliminate the use of chemical fungicides or minimize their negative impact on human and environmental health by minimizing the number of applications. In this study, the as female parent cultivar of Narince; It was carried out on 447 F1 genotypes obtained as a result of crossing studies in which Isabella, Regent and Kishmish Vatkana cultivars were used as male parents. In 2021, the first year of the study, the genotypes were examined in terms of leaf quality by considering some OIV criteria, and at the same time, 100 promising genotypes were selected by pre-selection by weighted rating method after being evaluated in terms of susceptibility to powdery mildew. In 2022, the second year of the study, a second selection was made by marker-based selection in the selected genotypes, wrapping and the sense of taste in genotypes with good leaf quality, powdery mildew inoculation in greenhouse and laboratory conditions. As a result of the study, in terms of leaf quality; two genotypes (NVL-35, NVL-77), three genotypes with low powdery mildew density and good leaf quality (NRG-181, NRG-146 and NRG-66), three genotypes (NVL-58, NRG-194 and NRG-66) for leaf taste testing came into prominence. In the combinations of Narince x Kishmish Vatkana and Narince x Isabella, resistant genotype could not be determined as a result of powdery mildew scoring. Narince x Regent hybrids generally showed powdery mildew symptoms late. Six genotypes (NRG-7, NRG-174, NRG-195, NRG-196, NRG-197 and NRG 200) were identified, with consistent powdery mildew scores and marker-based selection results. In the study, susceptibility to powdery mildew of Narince, Künefi, Erciş, Dökülgen, Fenerit, Hatun Parmagi, Horoz Karasi, Muhammedi, Karaerik, Vakkas, Italia and Kyoho cultivars were also investigated. Of these cultivars; Horoz Karasi showed powdery mildew symptoms late. Muhammedi, Hatun Parmagi and Erciş cultivars showed sensitivity against powdery mildew from the first weeks. The genotypes selected look promising have been preserved in the collection vineyard of Tokat Gaziosmanpaşa University, Faculty of Agriculture.