Dynamics of endogenous auxins, cytokinins and abscisic acid-like inhibitor in embryonic shoots of young Scots pine (Pinus silvestris L.) at the time of flower primordia initiation

Abstract

Auxins, cytokinins and ABA-like inhibitor were determined in the embryonic shoots of young pines. It was stated that the transition from vegetative to reproductive stage of pine development is connected with the decrease of the IAA level. In the group of vegetative plants an unknown auxin-like substance was detected. This substance appeared in the period of generative development initiation. It was also stated that differentiation of female inflorescences was connected with the increase of the level of ABA-like inhibitor. However the differentiation of male ones was connected with decrease of the amount of this inhibitor. No correlation between sex determination and the level of auxins and cytokinins was observed.