ON THE ROLE OF ETHYLENE IN SEED-GERMINATION AND EARLY ROOT-GROWTH OF PISUM-SATIVUM

Requirement for endogenous ethylene in germination of pea seeds was in vestigated by using inhibitors of ethylene synthesis, 2-aminoethoxylvi nyl glycine and cobalt ions, and ethylene action, 2,5-norbornadiene. I n particular, continuous application of high concentrations of aminoet hoxyvinyl glycine alone or combined with cobalt ions did not affect ge rmination, although inhibiting almost completely ethylene production. On the other hand, these inhibitors increased the length and decreased the diameter of elongating pea roots. Anatomical analysis showed that changes in root morphology were related to changes in the dimensional shape of cortical cells. Application of 2,5-norbornadiene from the st art of imbibition strongly inhibited pea germination and the inhibitio n was mostly counteracted by ethephon. However, seeds fully escaped th e sensitivity to NBD after 15 h of imbibition.