The effects of simulated trampling on shoot morphology and ethylene production of a trampling-tolerant perennial forb asiatic plantain were investigated. Trampling increased the number of leaves or inflorescences per plant, the petiole diameter, and the leaf blade length to width ratio but decreased the leaf blade width to petiole diameter ratio and the inflorescence length. Ramets subjected to trampling produced more ethylene than did nontrampled ramets originating from the same root crown. Moreover, an ethylene releaser ethephon decreased the leaf blade width to petiole diameter ratio and increased the leaf blade length to width ratio, in a manner similar to the changes induced by trampling. These results suggested that trampling-induced ethylene might be closely related to some of the adaptive morphological changes in asiatic plantain in response to trampling.
Nomenclature: Ethephon, 2-chloroethylphosphonic acid; asiatic plantain, Plantago asiatica L.