Light quality effects on in vitro shoot proliferation of Spiraea nipponica
department or school: Land and Food Systems, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Herrington, Edward John
issued: 2010-09-29T19:50:39Z
issued: 1990
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: The work on Spiraea in vitro shoot cultures was done to determine the feasibility of using light quality to modify endogenous phytohormone balances to decrease apical dominance. Such an effect would enable a reduction in the high levels of exogenous cytokinin benzyladenine (BA) applied in culture and thus reduce potential side-effects. The Spiraea in vitro light quality response was characterized by examining the effects of different light wavelengths on growth. A mixture of red/FR induced rates of shoot proliferation with 0.25 mg/1 BA that were as high as rates obtained under white light with 0.5 mg/1 BA. Shoot quality, as determined by the proportion of shoots 1 cm or longer (useful shoots), was highest under red/FR light. The lowest shoot proliferation rate was observed under blue light. When light wavelengths intermediate between blue and red light (green, yellow, and orange) were applied to explants only minor growth modifications occurred. Green light did not inhibit shoot initiation but inhibited shoot elongation at the 0.5 mg/1 BA level. The efficacy of the light source-filter combinations in the first experiment was studied in two further experiments. With the three light sources (tungsten filament, fluorescent, and metal halide) together with a blue filter, results supported the putative blue light inhibitory effect suggested in the first light quality experiment. Under the red filter, the tungsten filament source induced the highest shoot number means at both BA levels used (0.25 and 0.5 mg/1). Two factors may have contributed to the red/FR effect observed in the first experiment; the time under an incubation light regime before transfer to the treatment regime, and the photon fluence rate of each regime. In the subsequent study to examine these factors, shoot initiation was optimized at the lower BA levels of 0.25 and 0.4 mg/1 when cultures under low fluence red/FR were transferred after four weeks to white light of a higher fluence for one more week. Gl…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/28809
note: LIGHT QUALITY EFFECTS ON IN VITRO SHOOT PROLIFERATION OF SPIRAEA NIPPONICA B . S c . ( B o t a n y ) , U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1983 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF THE FACULTY OF GRADUATE STUDIES We a c c e p t t h i s t h e s i s as conforming t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA September 1990 (c) Edward John H e r r i n g t o n , 1990 By Edward John H e r r i n g t o n MASTER OF SCIENCE i n PLANT SCIENCE In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia Vancouver, Canada DE-6 (2/88) Abstract i i The work on Spiraea i n v i t r o shoot c u l t u r e s was done t o determine the f e a s i b i l i t y of u s i n g l i g h t q u a l i t y t o modify endogenous phytohormone balances t o decrease a p i c a l dominance. Such an e f f e c t would enable a r e d u c t i o n i n the high l e v e l s of exogenous c y t o k i n i n benzyladenine (BA) a p p l i e d i n c u l t u r e and thus reduce p o t e n t i a l s i d e - e f f e c t s . The Spiraea i n v i t r o l i g h t q u a l i t y response was c h a r a c t e r i z e d by examining the e f f e c t s of d i f f e r e n t l i g h t wavelengths on growth. A mixture of red/FR induced r a t e s of shoot p r o l i f e r a t i o n w i t h 0.25 mg/1 BA t h a t were as h i g h as r a t e s obtained under white l i g h t w i t h 0.5 mg/1 BA. Shoot q u a l i t y , as determined by the p r o p o r t i o n of sh…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0302364
language: eng
degree discipline: Plant Science
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/28809