Assessment of molecular diversity and genetic relationship and structure of Iranian sugarcane germplasm using microsatellite markers

Considering the potential of sugarcane in terms of energy and sugar production the study of genetic diversity is the best way to use available genetic germplasm for breeding programs in this plant. Thirty microsatellite primer pairs were used to screen 160 varieties. In total 169 alleles were recorded with an average of 5.6 alleles per locus. The number of effective alleles per locus was ranged from 1.06 (locus AP-SSR03) to 1.921 (locus SMC119CG) with an average of 1.508. The PIC value was variable ranging from 0.06 (for AP-SSR03) to 0.5 (for SMC851MS). The principal coordinate analysis (PCoA) revealed six groups, so that the first three axes explained 15.20% of cumulative variation altogether. Clustering analysis was done using Neihbour-Joining algorithm and population structure analysis was performed using Bayesian method. The best number of sub-populations was identified as six. The grouping of genotypes in the sub-populations was not in consistent with their geographic origins. The grouping obtained from Bayesian method, phylogenetic relatedness analysis results and principal coordinates analysis grouping showed good agreement with each other. Analysis of molecular variance revealed that variation within subgroups was significantly higher than that of among subgroups. So it will be better to do selection within populations in order to select suitable parents in sugarcane breeding programs. The knowledge obtained in this study would be useful for breeding programs to improve the conservation and management of this valuable genetic resource to meet the demand of sugarcane cultivation for sugar and bioenergy production.