Since the beginning of agriculture about 10, 000 years ago, there was a concomitant increase in food supply with growth in human population. Increases in food production were ascribed to availability of new agricultural land for greater food production as well as increased yields of crops due to breeding. The rapid development of molecular biology techniques and their application to plant breeding have resulted in significant genetic gains in agricultural crops, some of which have already entered the market. Sugarcane is susceptible to many viral, bacterial, fungal, and phytoplasma diseases, and there are a number of diseases of unknown etiology. Conventional breeding efforts have attempted to address many of the constraints facing vegetatively propagated crops, but progress has been slow because most of the crops have complex genetic systems that makes it difficult to breed efficiently. Molecular markers are discovered by establishing statistical associations between variations in particular DNA sequences and any traits that may be of interest.