Molecular Markers EST-SSRs for Genotype-Phenotype Association in Sugarcane

摘要

Sugarcane supplies raw material for several byproducts, speciality sugar and ethanol is highly productive, but presents high phenotypic variability due to its genetic complexity, polyploidy and gene duplication; these factors limit genetic advances and productivity gains. The application of linkage disequilibrium (LD)-based association mapping is an alternative powerful molecular tool to dissect and exploit the genetic diversity in sugarcane and greatly accelerating plant breeding marker-assisted selection (MAS) programs. However, the extent of genome-wide LD has not been determined in sugarcane. We select nine genes coding for agronomic traits of interest and primers EST-SSRs was obtained for application in 80 improved genotypes and in 16 non-improved genotypes with phenotype identified from vegetative growth, biomass accumulation and sugars was obtained 210 amplicons of which 115 were polymorphic, on average 23.2 alleles was obtained in the each primer combination and the polymorphism information content was between 0.48 and 0.69. The genotypic analysis structured five groups with genetic distance of ～0.8 between different groups. Genotype-phenotype expression was detected with allele-specific with distance 5-43 cM of agronomic trait. These ESTs-SSRs allele-specific can be appointed to the MAS in sugarcane plant breeding.