SYNERGISTIC EFFECT OF GA-3 AND EDDHA ON THE PROMOTION OF FLOWERING IN THE PHOTOPERIODICALLY NEUTRAL PLANT SPIRODELA-POLYRRHIZA (L) SCHLEIDEN

The effects of gibberellic acid and ethylenediamine-di-o-hydroxyphenylacetic acid (EDDHA) on flowering in the photoperiodically neutral plant, Spirodela polyrrhiza, were investigated. Sterilized isolated plants were grown axenically in modified Pirson-Seidel nutrient medium with Heller microelemental nutrient solution, illuminated by 3000 +/- 100 lx from 6 gro-lux fluorescent tubes (Sylvania 40 W/220 V). The temperature was kept constant (28 +/- 1-degrees-C). GA3 and EDDHA were added prior to, or after, sterilization of the nutrient medium. Under long-day conditions, the combination of GA3 (150-mu-g.L-1) and EDDHA (7.02 mg.L-1) has a synergistic effect on the promotion of floral induction.