Floral induction in Wolffia microscopica by salicylic acid and related compounds under non-inductive long days

Abstract

Flowering in Wolffia microscopica, a short-day plant, could be induced with salicylic acid (SA), under long days. Aspirin, benzoic acid and salicylaldoxime were also effective for induction of flowering in this duckweed. Amonsgt these, SA is the most effective compound, as it could induce flowering even at 10^-7 M. Flowering was further enhanced when Wolffia fronds were subjected to short days, in the presence of SA. However, SA neither showed any effect on flowering ofW. microscopica in the absence of EDTA in the nutrient medium, nor could it, by itself, support even the vegetative growth. The probable mechanism of action of SA has also been discussed. It appears that the effect cannot be due simply to chelation of metal ions and perhaps the salicyl moiety itself exerts a specific effect.