CO2倍增对铁皮石斛光合特性和生长的影响

Effects of Doubling the CO2 Concentration on Photosynthetic Characteristics and Growth of Dendrobium officinale

【目的】评估CO2倍增对铁皮石斛光合特性和生长的影响。【方法】以铁皮石斛秋芽为试材,比较CO2浓度400μmol/mol(大气浓度,对照)和800μmol/mol(处理浓度)处理180 d对铁皮石斛光合特性、生长和有效成分的影响。【结果】CO2倍增提高了铁皮石斛的净光合速率、气孔导度、蒸腾速率和水分利用率,但铁皮石斛未出现"光合适应"现象。CO2倍增也显著增加了铁皮石斛的茎干质量、茎鲜质量、茎高、单株叶片数和叶片厚度,分别比对照提高30%、13%、49.3%、42%和3.5%,而单叶面积和比叶面积则分别显著下降11.8%和20%;CO2倍增处理叶片可溶性蛋白含量比对照显著提高19%,而茎的多糖、生物碱、总氨基酸和总黄酮等有效成分含量均有所提高,但与对照差异不显著。【结论】CO2倍增处理能显著促进铁皮石斛的生长,提高其主要药用部位茎的产量。

【Objective】The study was to evaluate the effects of doubling the CO2 concentration on photosynthetic characteristics and growth of Dendrobium officinale.【Method】With the autumn buds of D.officinale as test materials,the effects of treatments with CO2 concentration of 400 μmol/mol (atmospheric concentration,control) and 800 μmol/mol (treatment concentration) for 180 days on the photosynthetic characteristics,growth and effective components of D.officinale were compared.【Result】After doubling the CO2 concentration,the net photosynthetic rate,stomatal conductance,transpiration rate and water use efficiency of D.officinale were increased significantly compared with those of the control,however,there was no photosynthetic acclimation on D.officinale during the experiments.The stem dry weight,stem fresh weight,stem height,numbers of leaves and leaf thickness were also significantly increased in double treatment,with the increases of 30%,13%,49.3%,42% and 3.5%,respectively,while the single leaf area and the specific leaf area were decreased by 11.8% and 20%,respectively.The soluble protein content in leaf was increased by 19%.The contents of polysaccharides,alkaloids,total amino acids and total flavonoids in stem were slightly improved,but there was no significant difference compared with those of the control.【Conclusion】The growth of D.officinalis could be promoted by doubling the CO2 concentration,and the yield of its main medicinal part (stem) was increased.