Polyploidy Induction by Sodium Azide and Ethyl Methane Sulfonate in Grape Genotypes

Continuous improvement of vine rootstocks and grape varieties is necessary for the sustainability of viticulture. In this context, grapevine breeding and especially the development of polyploid grapevine genotypes offer opportunities. This study investigated the effectiveness of sodium azide (SA, five dozes and two treatment duration) and ethyl methane sulfonate (EMS, four dozes and two treatment duration) in inducing polyploidy. In Ekşi Kara and Gök Üzüm grape cultivars and 41B and Fercal grapevine rootstocks, different parameters were studied, such as seedling growth, stoma, chlorophyl and chloroplast observations, and cytogenetic analysis. In the experiment, each mutagen dose was applied to twenty seeds, 300 for each genotype and 1200 seeds in total. As a result of both mutagen treatments, a total of 268 seedlings survived: 39 in cv. Ekşi Kara, 48 in cv. Gök Üzüm, 78 in 41B and 103 in Fercal. A total of 50 seedlings, 8 in Ekşi Kara, 17 in Gök Üzüm, 9 in 41B and 16 in Fercal, were selected through preliminary screening by observing shoots, leaves, chlorophyll, stomata and chloroplasts, and the polyploidy level was examined by flow cytometry (FC) analysis. In the FC analysis, only one seedling selected from the Gök Üzüm SA 0.05% 2-h treatment was confirmed to be triploid. In addition, in the chromosome count performed on the root tip-sample of the seedling selected by FC analysis, 57 chromosomes were counted that this was exactly triploid with 3n = 57 chromosomes, and ploidy verification was repeated. The triploid Gök Üzüm seedling obtained in this study is the first productive result in which polyploidy was induced with SA in grapevine genotypes. In subsequent studies to induce polyploidy in grapevine, SA 0.05% 2-h treatment may be recommended.