Microsatellite markers as an important tool in the genetic analysis of sugarcane (Saccharum ssp)

Cultivated sugarcane clones (Saccharum spp., x = 8) are derived from complex interspecific hybridisations between the species S. spontaneum and S. officinarum. To analyse this complex genome, we have investigated the potential of microsatellite sequences as genetic markers with respect to their abundance, variability and ability to detect polymorphisms. An international consortium has been developed to isolate and characterise these microsatellites. To date, primer pairs have been designed and synthesised for over 100 microsatellite sequences isolated from an enriched sugarcane microsatellite library. The majority have produced polymorphic products when tested on 5 Saccharum genotypes, including two parents and a single F1 progeny of a mapping cross. Fluorescently labelled primers for 8 of these microsatellite markers were synthesised and used to confirm size differences down to 1 bp on an ABI 310 genetic analyser. Data gathered indicate that microsatellite markers can identify co-dominance, polymorphism and inheritance in sugarcane. Microsatellites can therefore be used as a tool in fingerprinting sugarcane genotypes, in genetic mapping, and to assist in selecting specific, genetically diverse parents for use in introgression.