大气CO_2浓度升高对辣椒光合作用及相关生理特性的影响

Effects of elevated [CO_2] on photosynthesis and relevant physiological characteristics of pepper( Capsicum annuum L.)

研究大气CO_2浓度升高对辣椒光合作用及相关生理特性的影响,揭示大气CO_2浓度变化与辣椒光合作用及生理指标之间的关系,为辣椒的栽培管理及果实加工提供理论参考。利用OTC(open-top chamber)系统,采用盆栽试验,研究CO_2浓度增高200μmol·mol-1对辣椒形态指标、叶片生理指标、光合参数、光合色素、维生素C(Vc)含量、糖类化合物和产量的影响。结果表明:大气CO_2浓度升高促进了辣椒生长,增加株高、产量和植株总生物量。叶片净光合速率(Pn)、胞间CO_2浓度(Ci)和水分利用效率(WUE)明显提高;开花坐果期气孔导度(Gs)和蒸腾速率(Tr)增加,结果期气孔导度(Gs)和蒸腾速率(Tr)下降;大气CO_2浓度升高促进辣椒叶和辣椒果实中Vc含量的显著升高,叶片中叶绿素和糖类化合物含量也显著增加;CO_2浓度升高能改善辣椒叶片光系统,增加光合作用,促进辣椒代谢物质的积累,有利于辣椒的生长发育。

Studying the effect of elevated atmospheric CO2 concentration on photosynthesis and relevant physiological characteristics of pepper and revealing the relationship between atmospheric CO2 concentration and photosynthesis and physiological indexes of pepper can provide a theoretical basis for the cultivation and fruit processing of pepper. Changes in morphological parameters, leaf physiological indexes, photosynthesis, photosynthetic pigment content, Vc content, biomass and yield in response to elevated CO2 concentration （control level＋200 μmol·mol-1） were determined in pot experiment using an open-top chamber （OTC） experimental facility. The results showed that the elevated CO2 concentration promoted the growth of pepper and increased plant height, yield and total biomass. At elevated CO2 concentration, leaf net photosynthetic rate （Pn）, intercellular CO2 concentration （Ci） and water use efficiency （WUE） increased, stomatal conductance （Gs） and transpiration rate （Tr） increased in blossom and fruit period while decreased during fruiting stage. Elevated CO2 concentration also significantly increased Vc content in the leaves and fruits and the contents of chlorophyll and carbohydrate in the leaves of pepper. Elevated CO2 concentration improved the photosynthetic system and increased the photosynthesis of pepper leaves, and then promoted the accumulation of metabolic substances, which are beneficial to the growth and development of pepper.