掌叶木幼苗对不同光照强度的响应

The Responses of Hadeliodendron bodinievri Seedling to Different Light Intensity

采用人工模拟不同的光照条件(100%全光照、40%光照、20%光照、10%光照)进行盆栽试验,探讨不同光照条件对掌叶木幼苗生长、生理指标的影响。结果表明:在不同光照环境条件下,掌叶木1年生幼苗高生长量差异显著,地径生长量差异不显著;总生物量、叶生物量、茎生物量、根冠比均随光照强度降低而减少,各器官生物量分配均为:叶>根>茎;随着光照强度的减弱,幼苗净光合速率、蒸腾速率、叶绿素a/叶绿素b均表现出下降的趋势,叶片中SOD、MAD、质膜相对透性、叶绿素a、叶绿素b、叶绿素总量均呈不同程度的上升趋势。研究表明适当遮荫有利于掌叶木幼苗的培育。

The pot experiment was conducted with artificially simulating different light conditions （100% full light ;40% ,20% and 10% of full light） ,in order to determine the effects of different illumination conditions on the physiological and growth indexes of Hadeliodendron bodinievri seedlings. The results show that the high growth was significantly different and diameter growth was not sig- nificantly different of one year old Hadeliodendron bodinievri seedlings under different light environmental conditions. Total biomass, leaf biomass, stem biomass and shoot ratio decreased with light intensity reducing, the biomass allocation are leaf 〉 root 〉 stem ; With the increasing of shading intension, the photosynthetic rate and transpiration rate of seedlings decreased; the contents of MDA, the chlorophyll-a, chlorophyll-b,total chlorophyll, the membrane permeability and the SOD activity all increased gradually with the de- crease of light intensity, and the chlorophyll a/b ratio under severe shading decreased significantly. The research results indicated the appropriate shading measure should be adapted to cultivating I-Iadeliodendron bodinievri seedlings.