Analysis Of Genetic Diversity In Chinese 56 Broomcorn Millet (Panicum Miliaceum L.) Resources Using Genic-SSR Markers

Broomcorn millet(Panicum miliaceum L.) could be tolerant to extreme drought climate and infertile soil. The specie germplasms has a wide range of spread in the whole world and a shorter growth cycle. The study revealed genetic diversity of 56 millet accessions from China using Genic-SSR molecular markers. The L16(44) orthogonal experiment was carried out to explore the optimum system for Genic-ssr PCR reaction, and develop the polymorphic primers and detect the loci of SSR among 56 broomcorn millet accessions by using the efficient analysis system--Fragment Analyzer’s automated capillary electrophoresis. Meanwhile, we used STRUCTURE 2.3.1 and POPGENE32 software to run genetic diversity analyses of 56 broomcorn millet accessions. The main results were as follows:1. Through the orthogonal experimental design, a 20μl reaction system was established, which contained a 0.2 mM dNTPs,0.2 μM SSR primer,1.5 mM Mg2+, and 0.5 U Taq DNA Polymerase.2.220 pairs of Genic-SSR primers were designed and synthesized in this test. Among them, 129 pairs were effective primers that accounted for 58.6% of the total number of primers.11 pairs of primers with good polymorphism was identified that accounted for 8.5% of the total number of effective primers. Most of the repeating loci for these screened polymorphic primers were A and T. The repeat unit included (AA)n, (AT)n, (CTT) n, and so on.3. Population genetic structure was analyzed in the 56 broomcorn millet accessions by STRUCTURE 2.3.1 and POPGENE32 software, which clustered into 7 subgroups. From the clustering results, the broomcorn millet of the same subgroup came from two or more different provinces, but these broomcorn millets from the same area were not completely gathered as the same subgroup. The results showed that these broomcorn millet germplasm resources have not obvious distribution pattern related with geographic regions.