论文部分内容阅读
[目的]比较环草石斛和铁皮石斛试管苗叶片的气孔特征和光合特性。[方法]对环草石斛和铁皮石斛不同生长发育时期试管苗叶片的气孔进行扫描电镜观察,并用调制式荧光仪测定荧光诱导光响应曲线。[结果]在各个生长发育时期,环草石斛试管苗叶片的气孔密度均明显高于铁皮石斛,而气孔开放率则较低。随着生长时间的延长,环草石斛和铁皮石斛试管苗叶片气孔的大小变化不大,而气孔的数量则逐渐增加,气孔密度分别增加了83%和17.6%,两者均以播种生长240d时叶片的气孔开放率最高。在设定的3种光照强度下,环草石斛试管苗叶片气孔开放程度随光强的增加而增大,光强为54μmol/(m2.s)时气孔的开放度最大。在相同的培养条件下,环草石斛试管苗的最大电子传递速率14μmol/(m2.s)和光饱和点318μmol/(m2.s)均低于铁皮石斛20μmol/(m2.s),483μmol/(m2.s),其潜在的光合作用能力较差。[结论]不同种类石斛试管苗的气孔特性不同,因而光合速率也不同。通常组培室内的光强为27μmol/(m2.s),这样的条件下,两种石斛试管苗叶片气孔的开度都未达到最佳状态。若能遵循试管苗对光照强度的需求规律,选择合适的培养条件,增大气孔开度,提高光合速率,将更有利于试管苗的生长发育。
[Objective] The aim was to compare the stomatal characteristics and photosynthetic characteristics of Dendrobium officinale and Dendrobium officinale in vitro. [Method] The stomata of test tube seedling leaves of Dendrobium officinale and Dendrobium officinale were observed by scanning electron microscope (SEM) at different growth and development stages, and the fluorescence induced light response curve was measured by using the modulation fluorescence instrument. [Result] The stomatal density of Dendrobium officinale in vitro was significantly higher than that of Dendrobium candidum at all growth stages, while the stomatal opening rate was lower. With the extension of growth time, the stomatal size of the leaves of Dendrobium officinale and Dendrobium candidum changed little, but the number of stomata increased gradually, the stoma density increased by 83% and 17.6% respectively, both of which were planted for 240 days Leaf stomatal opening rate is the highest. Under the three light intensities, the stomatal opening of the leaves of Dendrobium officinale increased with the increase of light intensity, and the stomatal opening was the largest when the light intensity was 54μmol / (m2.s). Under the same culture conditions, the maximum electron transfer rate of 14μmol / (m2.s) and light saturation point 318μmol / (m2.s) of D. officinale were lower than that of 20μmol / (m2.s), 483μmol / ( m2.s), its potential for photosynthesis is poor. [Conclusion] The stomatal characteristics of different kinds of Dendrobium plantlets were different, so photosynthetic rate was also different. Normally, the light intensity in the tissue culture chamber is 27 μmol / (m2.s). Under these conditions, the opening of stomata of two Dendrobium candidum leaflets did not reach the optimum state. If we can follow the law of the demand for light intensity of tube seedlings, select the appropriate culture conditions, increase the stomata opening, increase photosynthetic rate, will be more conducive to the growth of test tube seedlings.