Effects of Light Quality on Vegetative Growth and Flower Initiation in Phalaenopsis

• Main Authors: Kumala Dewi, Yekti Asih Purwestri, Yohana Theresia Maria Astuti, Lila Natasaputra, Parmi P
• Format: Article
• Language: English
• Published: Universitas Gadjah Mada, Yogyakarta 2015-12-01
• Series: Indonesian Journal of Biotechnology
• Online Access: http://journal.ugm.ac.id/ijbiotech/article/view/8632

The effects of LEDs (Light-Emitting Diodes) emitting different colours namely red, blue, red and<br />blue, and white lights on vegetative growth and fl ower initiation of Phalaenopsis have been evaluated.<br />Phalaenopsis“otohine/taisuco fi re bird” seedlings in vitro were subjected to different light qualities for either<br />2 or 4 weeks, and then each seedling was planted in a plastic pot containing sphagnum and grown in the<br />growth chamber under similar light quality for 3 months. For fl ower induction, mature Phalaenopsis plants<br />having 4 – 6 leaves were grown for 3 months in the growth chamber under different light qualities. The leaf<br />span, chlorophyll, gibberellin and cytokinin content were determined. In addition, the expressions of FT-like<br />gene in the leaf, axillary bud, fl ower bud and stalk were examined.<br />Vegetative growth was enhanced under blue, red-blue or white LEDs compared to that of the control.<br />Gibberellin and cytokinin content increased in the seedlings subjected to white LEDs. Based on the average<br />of leaf span increment it was suggested that the growth of Phalaenopsis seedlings can be promoted by giving<br />either blue, red-blue or white LEDs. From the second experiment, it was found that fl ower induction in<br />Phalaenopsis can be obtained in plants that had just fi nished fl owering without the application of LEDs. The<br />expression of FT-like gene in the leaf as well as fl ower bud and stalk suggests that this gene is involved in<br />fl ower regulation of Phalaenopsis.