Mechanism of resistance in Australian sugarcane parent clones to smut and the effect of hot water treatment

Abstract. Resistance of sugarcane plants to smut is believed to be manifested by two mechanisms, (i) external resistance, governed by structural barrier of bud scale and/or chemical secretion from the bud, and (ii) internal resistance, regulated by interaction of plants and fungus within the plant tissue. Hot water treatments are routinely used to treat seed cane to eliminate a range of diseases including smut. It is believed that hot water treatment predisposes sugarcane plant to smut. This study was conducted to determine the resistance mechanisms of some important Australian parent clones, and their response to hot water treatment in relation to smut infection. Twenty-one clones, used regularly in the Australian sugarcane breeding program, were evaluated. Results showed that ∼47% of clones had external and 33% had internal resistance mechanisms, indicating that parent clones selected for this study possessed diverse mechanism of resistance. There is a possibility some or all clones with internal resist...