Genetic diversity analysis of Valencia and Navel group sweet orange cultivars by SSR markers

Abstract

Sweet orange [Citrus sinensis (L.) Osbeck] fruit is one of the main citrus fruits, Navel and Valencia group sweet orange being the most representative and recognizable species of this species. The aims of this study were to determine genetic relationships and diversity of 84 Navel and 36 Valencia groups of sweet orange using SSR (simple sequence repeat) molecular markers. Twenty-six SSR primers were tested on these accessions. Seven SSR primers produced thirteen polymorphic fragments, eight SSR primers produced monomorphic fragments, and eleven SSR primers produced no scorable fragments. Thirteen SSR primers produced a total of 29 fragments and 13 of them were polymorphic. The number of average polymorphic fragments per primer was 1.93. The mean polymorphism information content (PIC) and marker index (MI) are 0.16 and 11.74, respectively. The Dice’s similarity coefficient among Navel and Valencia group sweet oranges ranged from 0.42 to 1.00 and matrix correlation (r) was 0.79. In the cluster analysis, Navel group sweet oranges were indicated as a separate group from Valencia group sweet oranges. ‘Antalya (40)’ was most distinct accessions from the others.

Keywords

• Citrus sinensis L.
• Genetic diversity
• Genetic resources
• SSR