Assessment of genetic diversity among local accessions of melon and identification of DNA markers linked with agro-morphological characteristics

In this project, ۱۴ local melon accessions were collected from five regions of Iran and examined in a randomized complete block design with three replications in the field over two consecutive years. The combined analysis of variance showed significant differences between accessions for the majority of characters, including days to flowering, flower petal width, fruit ripening time, peduncle diameter, fruit storage at room temperature, seed width, and seed length. The interaction effect of genotype×year was significant for variables including days to flowering, leaf tail length, number of seeds per fruit, thickness of fruit flesh, fruit fresh weight, ۱۰۰-seed weight, and fruit width. Among the studied characters, fruit fresh weight and fruit length were selected through stepwise regression as remarkable variables that have direct and indirect effects, respectively, on total fruit yield. Regarding principal component analysis, the first two principal components (PCs) explained ۵۴.۵% of the data variability, and the studied accessions were distinguished into two groups based on their PC۱ and PC۲ scores. Using ۱۲ RAPD primers, ۱۴۶ loci were amplified across the studied melon accessions. Results showed that primer OPB۱۳, with a polymorphism information content value of ۰.۳۸, has significant power in screening local melon germplasm. Classification of the studied melon panel using the Jaccard similarity coefficient and UPGMA algorithm produced three main groups. In this study, molecular classification did not coincide with agro-morphological classification. Here, co-localized genomic loci were identified that could potentially be utilized in local melon breeding programs through marker-assisted selection.

کلیدواژه ها:

Genetic variability ، marker-trait association ، RAPD marker ، stepwise regression