Interactions of red and far-red light modification with temperature on shoot extension and flowering in stock (Matthiola incana(L.) R. Br.)

SummaryEffects of light and temperature on stem extension and flowering of M. incana were investigated. Stem extension was markedly suppressed by red (R)-rich spectrum treatment until the flower buds became visible, whereas it was slightly promoted or was not affected by the far-red (FR)-rich spectrum treatment. The R-rich spectrum treatment markedly suppressed the response to gibberellin A4 (GA4) by stem extension and the FR-rich spectrum treatment occasionally increased it. The FR-rich spectrum treatment accelerated flowering and the R-rich spectrum treatment delayed flowering under weakly flower-inducing temperatures. However, these phenomena were eliminated under strong flower-inducing temperatures. Dark treated plants did not initiate flower buds in spite of cold treatment. These results indicate that light quality is involved in regulation of stem extension and flowering but temperature is more responsible than light quality in the flowering of M. incana.