Genetic variability in strawberry (Fragaria x ananassa Duch.) cultivars assessed by morphological traits and EST-SSR markers of Rubus ellipticus

Strawberry (Fragaria x ananassa Duch.) being an important commercial member of Rosaceae family, accounts for high nutritive value in terms of antioxidative and antibacterial properties. Owing to its unique therapeutic values, present study was done with the objective of characterizing 20 Fragaria x ananassa cultivars from Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, India based on their morphological descriptors and expressed sequence tags - simple sequence repeat (EST-SSR) markers of Rubus ellipticus L. (Smith). Broad phenotypic variability among the Fragaria x ananassa cultivars was detected using morphological descriptors. A set of 68 R. ellipticus EST-SSR primers were used for cross transferability analysis in strawberry cultivars for polymorphic marker identification and genetic diversity analysis. Out of 68 EST-SSRs, 51 (75%) showed amplification among the strawberry cultivars. The average (PIC) values of all the polymorphic loci for 20 strawberry cultivars were 0.34. Highest polymorphism information content (PIC) value (0.68) was obtained with contig 218, followed by contig 714 (0.65) and contig 408 (0.63), indicating that contig 218 has the most regions of diversity as amplified with these SSR and was found most suitable for cross transferability. The unweighted pair group method with arithmetic mean (UPGMA) was designed showing two separate groups for 20 cultivars of Fragaria x ananassa. The present study revealed that R. ellipticus microsatellites when used were able to distinguish strawberry cultivars accurately.