Analysis of genetic diversity among high sucrose genotypes of sugarcane (Saccharum spp.) derived from CoC 671 using sugarcane specific microsatellite markers

Sugarcane breeders target genetic improvement for sucrose content using conventional and molecular approaches in order to produce more sugar per unit area. The sucrose rich clone viz. CoC 671 is a widely used parent in juice quality improvement programmes. The present study is carried out using twenty eight derivatives of CoC 671 bred through crossing as male parent, as female parent, selfing, through somaclonal variation and induced mutagenesis. The clones were evaluated based on 30 sugarcane specific STMS markers in order to identify more diverse types to be used as parents and to compare the efficiency of different breeding methods to generate more variability for imparting selection.. Genetic diversity was estimated using Dice, Jaccard’s and Simple Matching coefficient methods. STMS markers were found to be suited to detect genetic differences among the clones of common descent as supported by the lower similarity index values. Mean genetic similarity among the somaclones (SI value = 0.72), mutants (SI value = 0.81), clones derived from CoC 671 as a female (SI value = 0.73) parent and male parent (SI value = 0.70) clearly showed that the clones with CoC 671 as the male parent were more diverse and indicated the role of male parent in creating a more segregating population than when used as female parent. Tissue culture based selection through somaclonal variation and induced mutations were less efficient in creating variability than the conventional methods. More diverse clones and combinations were identified to be used in hybridization for sucrose improvement in sugarcane.