Endogenous hormone levels at technical maturing stage of sugarcane

Abstract

Ethylene evolution of leaf and contents of ABA and IAA in cane-tip were measured during late growth stage of sugarcane. The ethylene evolution of different leaves (the leaf with TVD was defined as leaf +1, other leaves were count downward) showed that the younger leaves had higher ethylene release rates and the older leaves lower. This indicated that the ethylene evolution in leaf was not associated with leaf ripening or senescence but possibly depended on the physiology of whole plants. There appeared ethylene evolution peaks at the onset of ripening process in all varieties examined. These ethylene peaks were more than triple of normal. The ABA accumulation characters varied from varieties. The ABA peak appeared at the onset of ripening, one or two week(s) before the ethylene peak presented, for Guitang15 and ROC16 but no discernible ABA peak for Guitang11. These results indicated that both ethylene and ABA would play roles in inducing ripening of sugarcane. And divers mechanisms of hormones action or interaction were suggested. IAA content increased at the early time of ripening stage, indicated that IAA did not play opposing role to ABA and ethylene in the ripening of sugarcane.