Molecular characterization of some local watermelon genotypes of Türkiye with SSR markers

This study investigates the genetic diversity and relationships among some of the Turkish watermelon landraces and commercial varieties using Simple Sequence Repeat markers. Watermelon genotypes primarily from the Marmara, Thrace, and Central Anatolia regions were analyzed to assess their genetic structure and potential value for breeding programs. The research employed 13 SSR markers, of which 10 were found to be polymorphic. Results revealed two main genetic clusters among the studied genotypes, reflecting their genetic relationships and potential origins. The genetic similarity analysis showed that the genotypes were grouped under two main branches, with specific genotypes exhibiting close genetic similarities. The study found an average number of alleles of 1.32 and an effective number of alleles of 1.18 across the analyzed SSR markers. The observed heterozygosity (Ho) was 0.135, while the expected heterozygosity (He) was 0.158. The Shannon's information index averaged 0.203, indicating moderate genetic diversity among the studied genotypes. These results align with previous studies suggesting a relatively narrow genetic base in cultivated watermelon. However, the identification of unique alleles in some Turkish landraces highlights their potential value for broadening the genetic base in watermelon breeding programs.