Abstract
Effects of day-length and GA3 on flowering and endogenous hormone levels during flowering process of Rhynchostylis gigantea (Lindl.) Ridl. were studied. Three-year-old plants were grown under natural condition and short-day (10 h of light) combined with GA3 at 0 and 3,000 ppm, for 3 months. The results revealed that short-day could induce flower faster than natural condition around two weeks. Short-day and natural condition had effects on stem height and bush width, while GA3 had effects only on number of leaves per plant. ABA in leaf seemed to decreased in all treatments accept under NC-GA3, there was a peak of ABA at 30 days. Furthermore, under SD, GA3 seemed to decrease ABA in leaf. In shoot, ABA concentration was increased during 0-30 days in all treatments, after that GA3 seemed to decrease ABA concentration under NC, while the ABA concentration kept constancy under SD. On the other hand, GA3 seemed to boot t-ZR up in leaf under SD, but did not in shoot, where GA3 seemed to drop t-ZR. The reducing ABA and increasing t-ZR in leaf and/ or shoot might be related to flower buds initiation and early flowering of R. gigantea, especially, under SD.
Highlights
Flowering is a process that plant changes from vegetative to reproductive phase, from leaf to flower (Boonyakiat, 2003; Taiz and Zeiger, 2007)
Plants grown under Natural condition (NC)-GA3 and those grown under NC+GA3 could give visible flower shoot on September 30th and 20th 2009, respectively; whereas those grown under SD±GA3 could give visible flower shoot on September 11th 2009, which was 19 days earlier than those grown under NC±GA3
This result was similar to the report that R. gigantea could give flower shoot faster after exposed to dark period of 14 and 16 h combined with night temperature of 18°C, which was faster than dark period of 14 and 16 h combined with night temperature of 20°C (Theesoda, 2004)
Summary
Flowering is a process that plant changes from vegetative to reproductive phase, from leaf to flower (Boonyakiat, 2003; Taiz and Zeiger, 2007). This process is controlled by hormonal level (Ruamrungsri, 2004) and environmental condition (Hew and Yong, 2004). Plants grown under short-day of 10 h and night temperature at 18 C could give visible flower spike at average of 30.67 days after treatment, whereas those receiving 8 h light and night temperature at 18 C could give visible flower spikes at average of 34.50 days after treatment. Plants grown under those two conditions could give flower faster than those grown under natural condition (Theesoda, 2004). Talee (2008) reported that R. gigantea receiving www.ccsenet.org/jas dark period at 14 h along with 1,000 and 3,000 ppm GA3 application could give flower faster than natural condition for about 5-7 weeks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
