Nature of light requirement for the flowering of Chenopodium rubrum L. (Ecotype 60� 47?N)

Abstract

It has been shown that induction of flowering in Chenopodium rubrum L. (ecotype 60° 47' N) seedlings in BCJ light conditions is intensity dependent (Cumming, 1969, Canad. J. Bot. 47, 1247-1250) and that, this intensity dependence is not based on photosynthesis (Sawhney and Cumming, 1971, Can. J. Bot. 49, 2133-2137). Since BCJ light emits a high proportion of energy in the far-red, and the High Energy Reaction (HER) has its action maxima in the far-red and blue regions of the spectrum, we tested the involvement of HER in the light induction of flowering in C. rubrum. Our results show that optimum intensities of blue light are effective in inducing flowering in C. rubrum. Red light exposure does not lead to flower induction. We suggest the HER may be involved in the flower induction of C. rubrum in light. However, when high energy in blue and/or farred is provided in presence of energy between 500-700 nm wavebands, there is no flowering in C. rubrum. We suggest that flower inducing activity of HER may be counteracted by flower inhibitory action of red wavebands.