Gibberellic Acid and Vernalization

Abstract

SEVERAL workers^1,2 have reported that treatment with gibberellic acid induces early flowering in certain biennial plants in the same season and thus replaces their normal low-temperature requirement. In these biennial plants, extension growth and flowering go hand in hand, and it is quite likely that gibberellic acid replaces vernalization treatment incidentally, by bringing about the former, which is an almost universal action of the chemical. In the present investigation this suggestion has been tested by determining the effect of gibberellic acid on the flowering of both vernalized and normal plants of Brassica campestris L., Cicer arietinum L., Linum usitatissimum L. and Lens esculanta Moench, none of which has any obligatory low-temperature need for flowering. In Brassica, the reproductive process is associated with a change in the growth habit of the plant from that of rosette formation to stem elongation, while in the rest it is not so.