Ethylene and abscisic acid in the control of development of the rhizome of Kohleria eriantha (Benth.) Hanst. (Gesneriaceae)

kohleria eriantha has rhizomes which are underground stems with buds enclosed by modified leaves, that store starch. the buds of this rhizome can develop in two morphological patterns: an aerial shoot (similar to the mother plant) or a rhizome, depending on the water level present in the substrate. development of the shoot was inhibited by low water availability (1 ml) in the substrate. it was verified that ethylene and aba were involved in controlling the development of the rhizome pattern under low water availability. treatments with ethrel, peg and aba induced shoot development whereas treatments with agno3 or avg inhibited shoot development. increased ethylene and aba were observed under conditions that inhibited shoot development. moreover, it is suggested that aba may induce the production of ethylene in the sections of the rhizome under low water availability.