Flowering in Pisum: Evidence That Vernalization Does Not Influence the Length of Evocation

Abstract

Two further lines of peas with a high response to photoperiod are shown to possess long-lasting vernalization responses. However, the expression of these responses varies between lines and appears to be related to the sensitivity of the apex to the flowering hormones.

Vernalization is shown to reduce the number of days of continuous light required to induce flowering and the number of leaves expanded at induction. Unlike previous reports, this suggests that seed vernalization does influence the inductive processes. The length of evocation does not appear to be influenced by vernalization regardless of whether this period is measured in plastochronic or chronological terms. These results suggest that the vernalization and photoperiod responses in peas cannot be separated into effects on evocation and induction respectively. Further, this result does not allow the mechanism of the previously reported shoot response of vernalization to be determined.