Genome-wide identification and characterization of novel non-coding RNA-derived SSRs in wheat.

Expression of eukaryotic genes is largely regulated by non-coding RNAs (ncRNA). Sequence variations in the regulatory RNAs may have critical biological consequences including transcriptional and post-transcriptional gene regulation. ncRNA-derived markers thus can be proved useful in molecular breeding, QTL mapping and association studies for trait dissection. In present study, we identified a total of 661 SSRs dwelling in pre-miRNA (15), small nuclear RNA (25) and lncRNA (621). Of these, 46 were validated and 100% amplification success was observed in selected wheat genotypes. A set of 36 ncRNA-SSRs markers was utilized for genetic variability assessment in forty-eight Indian wheat genotypes (which includes bread wheat, durum wheat and relatives). Number of alleles ranged from 1 to 4 with an average of two alleles per SSR locus. Mean PIC, observed heterozygosity and Shannon information index were found to be 0.258, 0.37 and 0.476 which suggests ncRNA-SSRs show higher polymorphism compared to genic SSRs but lower polymorphism compared to genomic SSRs. Thirty-six ncRNA-SSRs showed transferability ranging from 42.1% to 100%. Average genetic dissimilarity among wheat genotypes was found to be 0.29 based on Jaccard's dissimilarity. This is the first report of ncRNA-SSRs in wheat which will be useful for molecular breeding and genetic improvement of wheat.