Generation of denovo EST-SSRs and Validation in Newly Developed Interspecific Citrus Hybrids (Citrus maxima Merr. × Citrus sinensis (L.) Osbeck)

Interspecific hybridization of Citrus maxima Merr.(Pummelo) × Citrus sinensis (L.) Osbeck (Sweet Orange) resulted into new hybrids which is better than parents in terms of high juice recovery and decreased peel thickness. To characterize these newly developed 24 citrus hybrids and their 4 parents, a set of 50 de novo EST-SSR primers were generated. Of these specific primers, 19 showed polymorphism. Gene diversity (GD), average number of alleles per locus (An), polymorphism information content (PIC) and major allele frequency (Maf) observed were 0.36, 2.47, 0.30 and 0.73, respectively. Most of the hybrids (89%) along with red pummelo and male parents clustered together whereas white pummelo (PS-5 and PS-10) and hybrid (SCSH 3–10) clustered separately. Molecular markers clearly differentiated white and red pummelo parents in different groups. It is important to mention that, no previous investigations have done to characterize these interspecific citrus hybrids using EST-SSRs molecular marker. The information generated will be useful for characterization of interspecific citrus hybrids.