Microsatellite markers of finger millet (Eleusine coracana (L.) Gaertn) and foxtail millet (Setaria italica (L.) Beauv) provide resources for cross-genome transferability and genetic diversity analyses in other millets

The cross-genome transferability of 101 simple sequence repeats (SSR) markers of finger millet and 26 SSR markers of foxtail millet were analyzed in 8 other millets. In total, 33 finger millet and 2 foxtail millet SSR markers showed 100% cross-genome transferability in other millets. The cross-genome transferability of 101 finger millet and 26 foxtail millet SSR markers ranged from 47.52% to 61.38% and from 30.76% to 69.23% respectively. Expressed sequence tags SSR (EST-SSR) markers of finger millet showed higher level of cross-genome transferability than genomic SSR (gSSR) markers. The observed polymorphic information content (PIC) values were the same for finger millet and foxtail millet SSR markers which ranged from 0.14 to 1.00. Further, these data were also used for genetic diversity analysis among 8 millets using the software version 2.1 of NTSYSpc tool and PAST version 2. All millet species were grouped into one major cluster based on finger millet SSR markers, through UPGMA analysis. But two major clusters were observed by the analysis using foxtail millet SSR markers. Similarity value ranged from 0.238 to 0.714. Higher bootstrap values were observed in all cluster nodes. Successful analysis of genetic diversity was also confirmed by PCO and PCA analyses. This study would pave the way to understand the genetic structure of many nutritionally important millets lacking genomic resources. The SSR markers can also be used for further studies on analysis of genetic variation, population structure and germplasm characterization of millets.