EFFECT OF IN-VITRO CULTURE ON RUST RESISTANCE AND YIELD IN SUGARCANE

The purpose of this study was to compare the susceptibility to rust (P uccinia melanocephala) and the yield characteristics of sugarcane plan ts derived either from callus or bud cultures with those of plants obt ained by the normal method of vegetative propagation. Plants regenerat ed from callus cultures (somaclones) generally had higher rust severit y, thinner stalks and smaller leaves than the control. The magnitude o f these effects depended on the method used to obtain the somaclones. Plants derived from bud cultures also showed an altered rust resistanc e and had improved yield components in two trials. The effect on rust resistance persisted for in vitro-derived plants even after two vegeta tive propagations. It is thus necessary to take account of these effec ts when using in vitro culture techniques for sugarcane improvement or mass propagation.