Abstract
Vernalization treatment to pea seeds (cv. Atsumi-kinusaya) at 5°C for 20 days exerted flower promotion by 2.4 nodes. Endogenous gibberellins were found to increase in response to vernalization treatment although no difference could be detected in the plant height between vernalized and nonvernalized plants. Gibberellin activities were also detected in the water which contained materials that had diffused out of the vernalizing seeds. Bioassay data suggested that detected gibberellins from vernalized seeds and shoots are gibberellins possessing no OH substitution on C-3 position of ent-gibberellane ring. Exogenously applied gibberellin A3 and A7, possessing OH-substitution at the position, increased stem length but rather acted in inhibitory manner to the flowering as indicated by increase of the first flower nodes.
