光照强度对美花石斛试管苗生长及光合特性的影响

Effects of Light Intensity on the Growth and Photosynthetic Characteristics of Dendrobium loddigesii in vitro

关键词:  美花石斛  试管苗  生长发育  光合特性  荧光特性

Key words:  Dendrobium loddigesii  plantlets in vitro  growth and development  photosynthetic characteristics  fluorescence characteristic

摘要:

为探究光照强度对美花石斛（Dendrobium loddigesii）试管苗生长及光合特性的影响，研究对不同光照强度处理2个月和4个月的美花石斛试管苗的生长情况、多糖含量、光合特性和荧光特性进行测定和分析。结果显示，随着光照强度的增大，处理2个月和4个月的美花石斛试管苗的生长指标和多糖含量均显著增大；在光照处理2个月时，36 μmol·m^-2·s^-1的光照强度有助于试管苗光系统Ⅱ （PSⅡ）最大光化学效率的提高和热耗散能力的增强，而54 μmol·m^-2·s^-1的光照强度有助于试管苗碳循环系统的完善；在光照处理4个月时，54 μmol·m^-2·s^-1光照强度有利于试管苗光反应系统的完善和热耗散能力的增强。研究结果表明，美花石斛试管苗在不同发育时期对光照强度的要求不同，培育过程中可根据试管苗的生长节律进行光照强度的调节。

Abstract:

To study the effects of light intensity on the growth and photosynthetic characteristics of the test-tube seedlings of Dendrobium loddigesii, the growth indexes, polysaccharide content, photosynthetic and fluorescent characteristics of the test-tube seedlings of D.loddigesii treated with different light intensity for 2 months and 4 months were determined and analyzed. The results showed that the growth indexes and polysaccharide content of the test-tube seedlings of D.loddigesii at 2 months and 4 months were significantly increased with the light intensity. After 2 months of light treatment, 36 μmol·m^-2·s^-1 light intensity was helpful to improve the quantum efficiency and heat dissipation capacity of PSⅡ seedlings, while 54 μmol·m^-2·s^-1 light intensity was helpful to improve the carbon cycling system of the test-tube seedlings of D.loddigesii.After 4 months of light treatment, 54 μmol·m^-2·s^-1 light intensity was beneficial for the improvement of light system and the enhancement of heat dissipation ability.It is suggested that the light intensity requirements of the test-tube seedlings of D.loddigesii were different at different developmental stages, and the light intensity could be adjusted according to the growth rhythm of test-tube seedlings.