CO2浓度递增对蕨菜净光合速率的影响

目的]研究CO2浓度递增对蕨菜净光合速率的影响。方法]利用L1-6400便携式光合仪的红蓝光源控制系统和CO2控制系统,对蕨菜苗初期和苗中期的净光合速率变化进行测定。设定光合有效辐射分别为100和200μmol/（m2·s）,CO2浓度梯度为1 000、900、850、800、750、700、650、600、550、500、400、300、200、100、50、25和0μmol/mol。结果]在蕨菜＂第一生长阶段＂,其净光合速率随光合有效辐射和CO2浓度的上升而上升,在光合有效辐射为200 mol/（m2·s）,CO2浓度达到650μmol/mol时,净光合速率也表现出明显减缓,接近饱和现象;在＂第二生长阶段＂,其净光合速率也随光合有效辐射和CO2浓度的上升而上升,当CO2浓度达到750μmol/mol,光合有效辐射为200 mol/（m2·s）时,净光合速率也表现出明显减缓,接近饱和现象。结论]更好的了解了蕨菜的光合生理生态机制,为蕨菜的引种驯化、种植栽培、种质保存及产量的提高提供理论依据和技术指导。

Effects of Progressively Increasing CO_2 Concentration on Net Photosynthetic Rate of Pteridium aquilium

Objective] The aim was to study the effects of progressively increasing CO2 concn.on net photosynthetic rate(NPR) of Pteridium aquilium.Method] The red blue light source control system and CO2 control system of L1-6400 portable photosynthetic instrument were used to determine the NPR changes of P.aquilium in the early seedling stage and the middle seedling stage.The photosynthetic available radiation(PAR) were set up as 100 and 200 μmol/(m2·s),resp.and the CO2 concn.gradient were set up as 1 000,900,850,800,750,700,650,600,550,500,400,300,200,100,50,25 and 0 μmol/mol,resp.Result] In the "first growth stage" of P.aquilium,the NPR was increased with the rising of PAR and the CO2 concn.,when the PAR was 200 mol /(m2·s) and CO2 reached 650 μ/mol,the NPR also showed obvious slow,approaching to saturation phenomenon.In the "second growth stage" of P.aquilium,the NPR was also increased with the rising of PAR and the CO2 concn.,when the CO2 reached 750 μ/mol and the PAR was 200 mol /(m2·s),the NPR also showed obvious slow,approaching to to saturation phenomenon.Conclusion] The study provided the theoretical basis and the technical guidance for better understanding the photosynthetic and physioecological mechanism and for the introduction and domestication,planting cultivation,germplasm preservation and yield increase of P.aquilium.