RESISTANCE OF SUGARCANE RELATIVES INJECTED WITH USTILAGO-SCITAMINEA

We evaluated the resistance of 102 clones of sugarcane (Saccharum spp. ) relatives to Ustilago scitaminea, causal agent of sugarcane smut, in two greenhouse experiments. Relatives included Erianthus spp. section Ripidium, S. barberi/S. sinense, S. officinarum S. robustum, S. spont aneum, and Saccharum interspecific hybrids (cultivars). Clones of Eria nthus spp. section Ripidium were the most resistant and clones of S. o fficinarum and S. robustum were the most susceptible of the six taxono mic groups included in the first experiment. Clones in the second expe riment, predominantly S. spontaneum from recent germ plasm collection expeditions, were assigned to one of three groups depending on their g eographic origin. Clones from India, Indonesia, and the Philippines ha d means of 1, 37, and 51% infection, respectively. Exotic, smut-resist ant clones will be crossed with elite clones to enhance smut resistanc e in Louisiana sugarcane germ plasm.