Inhibition of photoperiodic floral induction in pharbitis nil by ethylene

Abstract

Application of ethylene at 100 ppm or higher completely inhibited flowering in Pharbitis nil when made during an inductive dark period. Exposing plants to ethylene before or after the inductive dark period produced only slight or almost no inhibition. Ethylene was effective when it was applied only to a cotyledon, but was ineffective when applied only to a receptor bud. Ethylene had no effect on translocation of the floral stimulus. Ethylene-treated cotyledon did not transfer any flower inhibiting entity. Thus, ethylene is considered to inhibit the induction process(es) in cotyledons.Except for an initial temporary cotyledon epinasty, ethylene treatment had no effect on the subsequent growth and vigor of plants. This temporary cotyledon epinasty disappeared within the next 24 hr. © 1972 Oxford University Press.