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

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,36μmol·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54μmol·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,54μmol·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。

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,36μmol·m^(-2)·S^(-1) light intensity was helpful to improve the quantum efficiency and heat dissipation capacity of PSⅡseedlings,while 54μmol·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,54μmol·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.