EFFECTS OF PLANT-GROWTH REGULATORS ON SHOOT GROWTH AND FLOWERING OF APERENNIAL PADDY WEED, SAGITTARIA-PYGMAEA MIQ

Plant growth regulators (PGRs) including gibberellins (GAs) were exami ned for their effects on shoot growth and flowering of a perennial pad dy weed, Sagittaria pygmaea Mig. Among PGRs tested, only GAs (A(1), A( 3), A(4), and A(5)), AC-94377 1,3-dioxo-2H-isoindol-2-yl)cyclohexaneca rboxamide] and 2,6-diisopropylphenoxyacetic acid (DIPA) promoted both shoot growth and flowering. Structural requirements of GAs for promoti on of flowering seemed to be different from those for shoot growth of the weed. In addition, since the course of flowering induced by DIPA w as clearly different from that observed in plots treated with GA(3) or AC-94377, different mechanisms may be involved in promotion of flower ing.