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Effects of Light Quality on Vegetative Growth and Flower Initiation in Phalaenopsis Kumala Dewi; Yekti Asih Purwestri; Yohana Theresia Maria Astuti; Lila Natasaputra; P. Parmi
Indonesian Journal of Biotechnology Vol 19, No 1 (2014)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (500.288 KB) | DOI: 10.22146/ijbiotech.8632

Abstract

The effects of LEDs (Light-Emitting Diodes) emitting different colours namely red, blue, red andblue, and white lights on vegetative growth and fl ower initiation of Phalaenopsis have been evaluated.Phalaenopsis“otohine/taisuco fi re bird” seedlings in vitro were subjected to different light qualities for either2 or 4 weeks, and then each seedling was planted in a plastic pot containing sphagnum and grown in thegrowth chamber under similar light quality for 3 months. For fl ower induction, mature Phalaenopsis plantshaving 4 – 6 leaves were grown for 3 months in the growth chamber under different light qualities. The leafspan, chlorophyll, gibberellin and cytokinin content were determined. In addition, the expressions of FT-likegene in the leaf, axillary bud, fl ower bud and stalk were examined.Vegetative growth was enhanced under blue, red-blue or white LEDs compared to that of the control.Gibberellin and cytokinin content increased in the seedlings subjected to white LEDs. Based on the averageof leaf span increment it was suggested that the growth of Phalaenopsis seedlings can be promoted by givingeither blue, red-blue or white LEDs. From the second experiment, it was found that fl ower induction inPhalaenopsis can be obtained in plants that had just fi nished fl owering without the application of LEDs. Theexpression of FT-like gene in the leaf as well as fl ower bud and stalk suggests that this gene is involved infl ower regulation of Phalaenopsis.
EFFECTS OF BLUE LIGHT AND PACLOBUTRAZOL ON SEED GERMINATION, VEGETATIVE GROWTH AND YIELD OF BLACK RICE (Oryza sativa L. 'Cempo Ireng') Kumala Dewi; Rizkika Zakka Agustina; Farida Nurmalika
BIOTROPIA - The Southeast Asian Journal of Tropical Biology Vol. 23 No. 2 (2016)
Publisher : SEAMEO BIOTROP

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1254.435 KB) | DOI: 10.11598/btb.2016.23.2.478

Abstract

Black rice (Oryza sativa L. 'Cempo Ireng') is one of local rice varieties in Sleman Regency, Yogyakarta. The black color is caused by high anthocyanin content which is important source of antioxidant. The cultivation of black rice is still limited due to its tall phenotype, long vegetative stage and low productivitycompared to white rice. Paclobutrazol is a growth retardant causing dwarfing in several crop plants and reducing lodging. Blue light can improve plant quality. This research was aimed to evaluate the effect of blue light and paclobutrazol on seed germination, vegetative growth and yield of black rice. The results showed that the average of seed germination as well as the activity of α-amylase of seeds subjected to blue light were lower compared to those subjected to sunlight; however, paclobutrazol concentrations did not affect seed germination percentage. The height of rice plants treated with paclobutrazol decreased in accordance with the increase of paclobutrazol concentration. Chlorophyll content and tiller numbers increased by paclobutrazol treatment of 12.5 ppm. Nitrate reductase activity was higher in rice seedlings subjected to blue light compared to those subjected to sunlight. Iron (Fe) content of rice plants treated with 25 or 50 ppm paclobutrazol increased compared to control. It was concluded that paclobutrazol application of 12.5 ppm already reduced plant height. The higher concentration of paclobutrazol applied the greater reduction on plant height was observed. Blue light treatment applied during black rice seed germination slightly reduced germination percentage and α-amylase activity in the germinated seeds. However, blue light treatment combined with paclobutrazol application during black rice seed germination increased chlorophyll content, tiller numbers and Fe content in black rice grain.