Genetic base-broadening in the West Indies sugar cane breeding programme by the incorporation of wild species.

Modern sugarcane varieties are complex interspecific hybrids and are highly polyploid with a degree of aneuploidy. Although progress was initially good, by the 1960s it was realized that the exceedingly narrow genetic base of the existing clones was beginning to impede further progress. The need for the introduction of new genetic material into breeding programmes was generally accepted. Several new collections of wild relatives of sugarcane were made, particularly of Saccharum spontaneum. A wider collection of the cultivated forms of S. officinarum was also accumulated. This chapter describes a genetic base-broadening programme in the West Indies that utilizes this wide diversity of genetic material. Essentially, the programme repeats the nobilization stage of the crop's evolution, on a wider genetic base.