遮荫对风箱果幼苗光合能力和碳水化合物积累的影响

Effects of Shading on Physocarpus amurensis Seedlings Photosynthetic Ability and Carbohydrate Accumulation

以1年生风箱果幼苗为材料,采用人工遮荫方式设置CK(全光)、轻度遮荫L1(60%全光)和重度遮荫L2(20%全光)3种光环境,测定不同光环境下风箱果幼苗的光合特性、光合色素含量、非结构性碳水化合物(NSC)积累等,分析风箱果幼苗对不同遮荫环境的适应性。结果表明:风箱果属于阳生树种,对光环境的变化非常敏感;遮荫显著降低了表观量子效率(AQY)、最大净光合速率(P_(max))、暗呼吸速率(R_d)、光补偿点(LCP)、光饱和点(LSP)和类胡萝卜素含量(Car)(P<0.05),显著提高了叶绿素a(Chla)、叶绿素b(Chlb)、总叶绿素(Chl)含量和叶绿素/类胡萝卜素(P<0.05);遮荫显著减少了根、茎、叶中NSC含量(P<0.05),尤其是L2时,分别比CK减少了52.5%、44.9%和43.9%。综上所述,风箱果幼苗对于遮荫环境的适应和调节能力较差,生产实践中应栽植在阳光充足的环境中。

For studying the adaptability of Physocarpus amurensis seedlings under different shading environment, we measured the photosynthesis characteristics, photosynthetic pigment content, non-structural carbohydrate（NSC） accumulation of one-year seedlings through three intensities of artificial shading （control （full light, CK）, moderate shading（60% of full light, L1 ） and heavy shading（20% of full light, L2））. P. amurensis was heliophilous trees, and was very sensitive to changes of the light environment. The shading resulted in significant decrease in the apparent quantum efficiency （AQY）, maximum net photosynthetic rate （P~,）, dark respiration rate （ Ra ）, light compensation point （ LCP ）, light saturation point （LSP） and carotenoid content（Car） （P 〈 0.05 ）, and significant increase chlorophyll a （Chla）, chlorophyll b （Chlb）, total chlorophyll（Chl） content and chlorophyll/carotcnoid（P 〈 0.05）. The shading had resulted in significant decrease in the NSC content of root, stem and leaf（P 〈0.05）, especially L2, decreased by 52.5%, 44.9% and 43.9%, respectively, compared to CK. Thus, the ability of adaptation and regulation of P. amurensis seedling to shading environment was inferior, and it should be planted in a sunny environment in practice.