Diversity of the germplasm of Saccharum species and related genera available for use in directed breeding programmes for sugarcane improvement

Sugarcane is primarily a crop raised by sett cuttings. After the discovery of fertility in sugarcane seeds, attempts have been made for its improvement through concerted breeding efforts. The first phase was limited to crossing among Saccharum officinarum clones and the resulted hybrids although had high sucrose content, lower fibre, lacked vigour, ratooning ability and resistance to diseases. In the second phase after the realization of adaptability to diverse environs, resistance to insect pests and diseases, and tolerance to abiotic stress and ratooning ability in the indigenous canes (S. barberi, S. spontaneum and S. robustum), a limited number of these was used in the crossing and subsequent nobilization for varietal improvement. However, the limited use of germplasm could not sustain the challenges to the crop, so also the pace of varietal development. Realization of the fact that further incorporation of S. spontaneum germplasm in breeding sporadic efforts paid dividends, attempts have been made to look into the diversity for traits of agronomic interest not only in Saccharum species, but also in the Saccharum complex, i.e. in the related genera. The present study reviews the diversity available for agronomic traits in Saccharum species clones and related genera which could be made available for use in directed breeding programmes for sugarcane improvement for the ever-increasing need of not only of sugar but also of the energy, paper and other value-added products from sugarcane.