In-silico identification of simple sequence repeat (SSR) markers and phylogenetic analysis from chloroplast genomes of the genus Bambusa

Microsatellites or simple sequence repeats (SSRs), are short DNA sequences composed of repetitive units typically 1 to 6 base pairs long. These highly variable sequences are found in both protein-coding and noncoding DNA regions and exhibit a high degree of polymorphism. In the present study, chloroplast genomes of five species of Bambusa viz. B. bambos, B. multiplex, B. teres, B. vulgaris, and B. tulda, along with three outgroup species viz. Sorghum timorense, Hordeum vulgare, and Triticum aestivum were retrieved from NCBI in FASTA and GenBank formats and screened for chloroplast SSRs (cpSSRs) using MISA Perl script. The sequence analysis of the chloroplast genomes of different species of Bambusa confirmed the presence of 144 cpSSRs. The number of cpSSRs varied among the five bamboo species, with B. vulgaris exhibiting the highest count (31) and B. multiplex showing the lowest (27). Tetranucleotides were the most observed repeats in Bambusa, followed by mono-, di- and trinucleotides. Of the 144 SSR markers identified, only 16 (11.11 %) were suitable for primer design since the remaining sequences failed to produce acceptable primer pairs. An unweighted pair-group method with an arithmetic mean (UPGMA) dendrogram was constructed to analyze the genetic relationships among the genotypes. This analysis revealed three distinct clusters among the genotypes. SSR markers were found to be informative in differentiating the species of Bambusa and were likely to find potential applications in genetic fingerprinting, population genetics, conservation, and phylogenetics.