Orta Asya'dan (Kırgızistan, Özbekistan) kavunlarda (Cucumis melo L.) genetik çeşitliliğin seçimi, değerlendirilmesi, morfolojik ve moleküler analizi

This study investigated the morphological and molecular biodiversity of 48 melon accessions, including 31 Kyrgyz, 16 Uzbek local genotypes, and 1 wild type, grown under greenhouse and open field conditions. Detaled analysis of 79 morphological and biochemical attributes, including seed, leaf, and fruit characteristics, was conducted to understand the relationship between genotypes. Significant variations were observed in seed size and shape, leaf morphology, and fruit attributes across different genotypes and growth conditions. Molecular analysis utilizing SRAP markers revealed significant genetic diversity, with an average polymorphism of 83%. Statistical techniques, including principal component analysis (PCA), descriptive statistics, UPGMA dendrogram, and structural analysis, were employed to interpret the data. The genotypes were categorized into four primary groups based on structural analysis. Cluster analysis indicated that the first two components accounted for 22% of the overall variation in morphological traits, while Principal Coordinates Analysis (PCoA) revealed that the top three axes accounted for 25.48% of the total molecular variance. AMOVA analysis highlighted significant genetic differentiation (11.6%) among the three populations. STRUCTURE analysis identified four distinct genetic clusters within the samples, with Cluster 2 showing the greatest heterozygosity. The study also assessed disease resistance among the melon genotypes. For Fusarium wilt, 70% of Kyrgyz genotypes and several Uzbek accessions demonstrated complete resistance to Fom1, while resistance to Fom2 was less common but included key accessions from both regions. Notably, some genotypes exhibited resistance to both Fom1 and Fom2, making them promising candidates for breeding programs aimed at developing Fusarium wilt-resistant melon cultivars. Susceptibility to anthracnose and powdery mildew varied among the genotypes, with some accessions like KGZ-13, KGZ-14, KGZ-15, and UZB-12 showing low susceptibility, highlighting their potential for breeding disease-resistant cultivars. This research provides valuable knowledge for breeding and conservation efforts, emphasizing the importance of genetic diversity in melon germplasm and identifying key genotypes for disease resistance and improved agronomic traits.