遮光处理对天女木兰幼苗光合特性的影响

在生长季节,对天女木兰幼苗采取四个遮光率处理（A（CK）：0;B：30％;C：60％;D：90％）,采用Lcpro＋便携式光合测定仪测定天女木兰幼苗的净光合速率日变化,同时测定叶片叶绿素含量,结果表明：天女木兰净光合速率日变化规律在不同的遮光处理下均呈现双峰型曲线,有明显的光合“午休”现象,净光合速率日最大值为B＞A＞C＞D;在四种遮光处理中,叶绿素含量为D＞C＞B＞A.综合得出：苗期采取30％遮光处理是最适宜的遮光率,适度遮光可促进幼苗生长.本研究为天女木兰在吉林地区的育苗、绿化应用提供了技术支撑.

On the Effects of Shading Treatment on the Photosynthetic Characteristics of Magnolia sieboldii Seedlings

During the growing season, four shading rate procession were taken on Magnolia sieboldii seedlings （A （CK）： 0; B： 30%; C： 60%; D： 90%）. used Lcpro＋ portable photosynthesis Instrument to determine the net photosynthetic rate day changes of by seedlings, meanwhile determine the chlorophyll content in leaves, and tested once every interval of 15 days. The results showed that： the diurnal variation of net photosynthetic rate of Magnolia siebodii showed a bimodal curve in different shading treatments, and had obvious ＂midday depression＂ phenomenon. The maximum of net photosynthetic rate were B〉 A〉 C 〉 D. In four shading treatment, the chlorophyll content were D〉 C〉 B〉 A. So got the conclusion that 30% of shading rate is the most suitable in seeding, moderate shading could promote seedling growth. Hope this study could provide technical supports in seeding cultivation and green applications in Jilin area.