Phylogenetic Analysis of Strawberry, Fragaria x ananassa (Rosaceae: Fragaria) using Cytochrome C Heme Attachment Protein (ccsA) Gene

Abstract

Phylogenetic relationships and genetic diversity were inferred using nucleotide sequences of chloroplast ccsAgene (cytochrome c heme attachment protein, for c-type cytochrome synthesis) of strawberry, F. x ananassa and other Fragaria species. Genomic DNA was isolated from fresh and green leaves of strawberry cultivar 'Chandler' seedlings. The ccsA gene sequence was amplified and isolated by using gene specific primers designed from consensus sequences of Fragaria species. After sequencing, the isolated ccsA gene sequence was corrected using BioEdit programs. Then ccsA nucleotide sequence isolated from cultivated strawberry (F. x ananassa) cultivar 'Chandler' was deposited in GeneBank at NCBI with accession number MK872805.1. Based on the BLASTn hit results, two separate datasets were prepared, one for Fragaria genus and other for Rosaceae family species to study the diversity analyses. MEGA 7.0 program was then used for phylogenetic analyzes and the detection of evolutionary genetic divergence between the species. For Fragaria genus which also included cultivated strawberry (F. x ananassa) ccsA gene sequence, the mean nucleotide composition was estimated as 29.3% A, 37.8% T, 15.5% C and 17.4% G. The lowest divergence distance i.e., 0.00 was estimated for Fragaris species, while the highest distance 1.00 was observed only for Fragaria nipponica (KY769125.1). Overall, the molecular phylogenetic analysis revealed that no genetic variation was observed in Fragaria species that was due to the highly conserved chloroplast nucleotide sequences of ccsA gene during evolution. However, the ccsA nucleotide sequences can be useful to study intra genus evolutionary relationship between Rosaceae family members.