摘要
油蒿是荒漠与半荒漠地区植物群落的优势种或主要伴生种,研究其在不同土壤水分条件下的光合作用特性及光响应过程对于了解其适应性非常重要。采用盆栽试验方法,在土壤体积含水率分别为19%、16%、12%、9%、5%的5个不同土壤水分水平上,研究了水分胁迫条件下油蒿的光响应过程,并分别采用3种不同光响应模型对其进行了模拟。结果表明:1)随着土壤含水量的降低,油蒿的净光合速率(Pn)总体上呈下降趋势,当光照强度(PAR)低于1 000μmol/(m2·s)时,体积含水率16%处理的Pn大于19%处理的。在受到较强光照条件下,随着光强的增加,19%、16%、12%、9%4种土壤水分处理下的Pn能维持在最大光合速率(Pnmax)水平,受到的光抑制不明显;5%土壤水分处理下的Pn在光照强度大于500μmol/(m2·s)后随光强的增加表现出下降趋势,显示出明显的光抑制现象。所采用的3个模型均能较好地拟合19%、16%、12%、9%4种土壤水分处理下油蒿光合作用的光响应过程及其表观量子效率、光补偿点和暗呼吸速率等光响应特征参数,但对于5%土壤水分处理下的油蒿光响应过程及其光响应特征参数,只有直角双曲线修正模型拟合结果较好,能够满足试验要求。
Artemisia ordosica is the dominant species in arid and semi-arid areas. It is critical for understanding the adaptability of A. ordosica to study its photosynthetic characteristics and light-response process under different soil moisture gradients. Photosynthesis of A. ordosica under five different soil water content （ 19% , 16% , 12% , 9% and 5% ） was measured to explore its photoresponse process under water stress by pot cultivating. Three photoresponse models were used to simulate the photoresponse and characteristic parameters. The results showed that the photosynthetic rate （P.） of A. ordosica came down with the decrease of soil water content. When photosynthetically active radiation （PAR） was lower than 1 000 ~mol/（m2＂s） , the P. of 16% water content treatment was higher than that of 19% treatment. Under intense radiation, P of 4 water content treatments （ 19% , 16% , 12% and 9% ） maintained the peak level （P ） as PAR increased and photoinhibition was not observed. When PAR exceeded 500 ~mol/ （mz＂ s）, the P. decreased with increasing PAR for the treatment with 5% soil water content , and photosynthesis was inhibited. Three photoresponse models used can well fit the simulation of photoresponse process and characteristic parameters, including apparent quantum efficiency, dark respiration and light compensation point for the treatments with 19% , 16% , 12% and 9% soil water content. However, for the treatment with 5% soil water content, only the rectangle hyperbola revised model can well fit the simulation of photoresponse process and characteristic parameters.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2014年第1期55-61,共7页
Journal of Beijing Forestry University
基金
"十二五"国家科技支撑计划项目(2012BAD16B02)
关键词
油蒿
水分胁迫
光响应模型
植物光合生理
Artemisia ordosica
water stress
photoresponse model
photosynthetic physiology of plants
