Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions
Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions
复制标题
DOI：
10.1111/j.1365-3040.2006.01581.x
复制
发表时间：
2006-11-01
影响因子：
7.3
通讯作者：
Ort, Donald R.
中科院分区：
文献类型：
--
作者：
Bernacchi, Carl J.;Leakey, Andrew D. B.;Ort, Donald R.
预计大气中二氧化碳的富集将增加 C3 植物的光合作用碳同化作用。迄今为止进行的受控环境研究分析表明，预计到 2050 年，植物在二氧化碳 ([CO2]) 浓度（接近 550 mu mol mol(-1)）下生长将刺激叶片光合碳同化 (A) 20% 至 40%。同时，到 2050 年，对流层臭氧 ([O-3]) 的浓度预计将增加，并且在 [O-3] 升高的受控环境中生长会显着减少 A。然而，在露天条件下，这两种增加对主要作物的同时影响从未得到测试。在连续三个生长季节中，对大豆 (Glycine max (L.) Merr) 进行了超过 4700 次 A、光合电子传递 (J(PSII)) 和气孔导度 (g(s)) 的单独测量。 （大豆）。实验处理采用完全复制的析因完整区组设计中的自由空气气体浓缩浓缩 (FACE) 技术。对照图中的平均 A 为 14.5 mu mol m(-2) s(-1)。 [CO2] 升高时，平均 A 升高 24%，并且治疗效果在 80% 的天数内具有统计显着性。白天最高气温与 [CO2] 升高时的平均日积分 A 之间存在很强的正相关性，这在很大程度上解释了日间 CO2 效应的变化。在水分胁迫条件下，[CO2] 升高对光合作用的影响也往往更大。升高的 [O-3] 处理对新展开的叶片的平均 A、g(s) 或 J(PSII) 没有统计学上的显着影响。 [CO2] 和 [O-3] 联合升高导致平均 A 的增加略小于单独升高 [CO2] 时的情况，但在 67% 的天数中显着高于对照。因此，根据为期三年的露天现场实验的结果，预测本世纪中叶大气成分的变化对光合作用、g(s)和通过光系统II的全链电子传输的影响将小于有关大豆和可能的大多数其他C3植物的相关受控环境研究的大量文献所预测的影响。
It is anticipated that enrichment of the atmosphere with CO2 will increase photosynthetic carbon assimilation in C3 plants. Analysis of controlled environment studies conducted to date indicates that plant growth at concentrations of carbon dioxide ([CO2]) anticipated for 2050 (similar to 550 mu mol mol(-1)) will stimulate leaf photosynthetic carbon assimilation (A) by 20 to 40%. Simultaneously, concentrations of tropospheric ozone ([O-3]) are expected to increase by 2050, and growth in controlled environments at elevated [O-3] significantly reduces A. However, the simultaneous effects of both increases on a major crop under open-air conditions have never been tested. Over three consecutive growing seasons > 4700 individual measurements of A, photosynthetic electron transport (J(PSII)) and stomatal conductance (g(s)) were measured on Glycine max (L.) Merr. (soybean). Experimental treatments used free-air gas concentration enrichment (FACE) technology in a fully replicated, factorial complete block design. The mean A in the control plots was 14.5 mu mol m(-2) s(-1). At elevated [CO2], mean A was 24% higher and the treatment effect was statistically significant on 80% of days. There was a strong positive correlation between daytime maximum temperatures and mean daily integrated A at elevated [CO2], which accounted for much of the variation in CO2 effect among days. The effect of elevated [CO2] on photosynthesis also tended to be greater under water stress conditions. The elevated [O-3] treatment had no statistically significant effect on mean A, g(s) or J(PSII) on newly expanded leaves. Combined elevation of [CO2] and [O-3] resulted in a slightly smaller increase in average A than when [CO2] alone was elevated, and was significantly greater than the control on 67% of days. Thus, the change in atmospheric composition predicted for the middle of this century will, based on the results of a 3 year open-air field experiment, have smaller effects on photosynthesis, g(s) and whole chain electron transport through photosystem II than predicted by the substantial literature on relevant controlled environment studies on soybean and likely most other C3 plants.