The Identification of Potential Genetic Markers in Sugarcane Varieties for the Prediction of Disease and Pest Resistance Ratings

The use of genetic markers that are linked to specific traits in sugarcane has the potential to increase the efficiency of the selection of improved varieties. Conventionally, markers are identified by analysing the segregation of potential markers and traits in the progeny of single crosses. However, this approach is not practical for sugarcane breeding programmes where replicated, well characterised progenies do not exist. The objective of this project was to investigate the potential of using commercial varieties for identifying markers associated with some of the important traits in sugarcane. This approach would be far more effective than dealing with single progenies since the traits of commercial varieties have already been characterised. The DNA of fifty commercial varieties of sugarcane was amplified by RAPD PCR using 41 arbitrary decamer primers. Analysis of the resulting banding profiles, obtained by agarose gel electrophoresis, yielded 54 reliable polymorphic fragments. Multiple regression analysis was used to identify putative markers associated with the traits of resistance to eldana, sugarcane mosaic virus and smut, and the predictive power of the markers was determined. Further analysis of sugarcane varieties using additional polymorphisms has the potential to identify markers linked to important traits. These markers could be used for marker-assisted selection to increase the efficiency of selecting for improved sugarcane genotypes for commercial release.