Flower color change of Boronia heterophylla as affected by light intensity and preservative chemicals

Abstract

This study was conducted to examine the effect of ethylene inhibitors [1-methylcyclopropene (1-MCP) and amininooxyacetic acid (AOA)] and light intensity on flower color deterioration of potted Boronia heterophylla plants. We tested 1-MCP and AOA as ethylene inhibitors or senescence-inhibiting chemicals, and ethepon as a senescence-promoting chemical. Along with two light conditions, lab and greenhouse, plants were treated with different combinations of chemicals and application methods (1-MCP vaporization, 1-MCP vaporization plus ethepon spray, AOA spray, AOA drench, AOA spray plus ethepon spray, AOA drench plus ethepon spray, and ethepon spray). The experiment was laid out in a split-plot design with four replications per treatment. The recorded environmental conditions in the greenhouse were 36.9% relative humidity, 23.2C temperature, and 901 Lmol-ni S light intensity, and in the lab were 68.2% relative humidity, 17.5 degrees C temperature, and 35 mu mol.m(-2). s(-1) light intensity. The changes in anthocyanin content and flower color were measured. Although senescence-inhibiting and senescence-promoting chemicals were expected to cause changes in the anthocyanin content and flower color deterioration, there was no signigicant differences among the treatments. Since keeping boronia plants in the greenhouse, having higher light intensity, is more efficient than keeping them in the lab to maintain antocyanin content and the flower color, it is concluded that light intensity had a major effect, while senescence-inhibiting and senescence-promoting chemicals played a minor role. More research using a diverse light intensities are needed in the future.