摘要
为探究水曲柳(Fraxinus mandschurica)幼苗对不同遮荫强度的响应机制,确定最适宜水曲柳幼苗生长的光环境,以2年生水曲柳实生苗为研究对象,人工设置不同的遮荫环境(L1-L4,透光率依次为76.4%,62.3%,39.8%,19.8%),并设置全光对照组(CK),对水曲柳幼苗生长以及光合特征指标进行测定。结果表明:仅在重度遮荫环境下,水曲柳幼苗生长会受到抑制,与其它处理出现显著性差异(P<0.05)。适度的遮荫可以提高水曲柳叶片的光合色素含量,其中透光率39.8%处理的水曲柳叶片光合色素含量最高,相较于CK提高了42.1%,总光合色素含量从大到小依次为L3>L4>L2>L1>CK。不同的遮荫强度会改变水曲柳叶片的非结构性碳水化合物含量。强光会使水曲柳幼苗叶片的PSⅡ反应中心被破坏,光合系统活性降低。透光率39.8%会增加PSⅡ反应中心的活性,提高电子传递效率和叶片的光能利用效率。因此,适度遮荫不会抑制水曲柳幼苗的生长发育,并会提高水曲柳幼苗叶片的光合色素含量与光能利用效率,39.8%的光照强度是最适合水曲柳幼苗生长的光照环境。
In order to investigate the response mechanism of Fraxinus mandschurica seedlings to different shading intensities and determine the most suitable light environment for their growth,this study used two-year-old Fraxinus mandschurica seedlings as the research subjects.Different shading conditions were artificially established(L1-L4,with light transmittance rates of 76.4%,62.3%,39.8%,and 19.8%,respectively),along with a full-light control group(CK).Growth and photosynthetic characteristics of the seedlings were measured.The results showed that only under severe shading conditions was the growth of Fraxinus mandschurica seedlings significantly inhibited,with a notable difference compared to other treatments(P<0.05).Moderate shading increased the photosynthetic pigment content in the leaves,with the highest content observed under the 39.8%light transmittance treatment,which was 42.1%higher than that of the CK.The total photosynthetic pigment content across treatments ranked as follows:L3>L4>L2>L1>CK.Different shading intensities also altered the non-structural carbohydrate content in the leaves.Strong light exposure damaged the PSⅡreaction centers in the seedlings,reducing the activity of the photosynthetic system.In contrast,a light transmittance of 39.8%enhanced the activity of PSⅡreaction centers and electron transport efficiency,thereby improving light energy utilization efficiency in the leaves.Therefore,moderate shading does not inhibit the growth and development of Fraxinus mandschurica seedlings but instead increases both photosynthetic pigment content and light energy utilization efficiency in the leaves.A light intensity of 39.8%is the most suitable light environment for the growth of Fraxinus mandschurica seedlings.
作者
高谢雨
林强
GAO Xieyu;LIN Qiang(Liaoning Provincial Institute of Forest Management;Liaoning Liaodong Peninsula Forest Ecosystem Observation and Research Station,Dandong 118002,China)
出处
《辽宁林业科技》
2026年第1期1-8,共8页
Liaoning Forestry Science and Technology
基金
辽宁省应用基础研究计划项目(2023JH2/101300151)。
关键词
水曲柳
遮荫
光合特性
Fraxinus mandschurica
shading
photosynthetic characteristics
