We measured the two-year-old Zhenzhuyouxing apricot's photosynthetic physiology parameters under different soil moister conditions (RWC is from 84. 7% to 22. 8%) with CIRAS-2 portable photosynthesis system. The parameters include net photosynthetic rate, transpiration rate, water use efficiency and intercellular CO2 concentration. Then we investigate the effect of soil moisture and light intensities on pho-tosynthetic. The results show that: (1) With the decreasing of soil moisture, net photosynthetic rate,transpiration rate,dark respiration rate and light saturation point represent a tendency of decreasing; apparent quantum yield increased first,then decreased;meanwhile light compensation point decreased first,then increased. (2) When the relative soil moister were from 43. 6% to 84. 7% ,the photosynthetic active radiation were from 800 to 2 000 μmol· m-2· s-1, it is good for Zhenzhuyouxing apricot to conduct higher net photosynthetic rate and water use efficiency. So we came to the conclusion that Zhenzhuyouxing apricot adapt, to a wider range of soil moisture and light intensity. (3)Stomata limitation is the main reason result in lower net photosynthetic rate when the soil moister were from 43. 6% to 73, 5%,and non-stomatal limitation result in lower net photosynthetic rate when the relative soil water moister were less than 43. 6%. Finally, we could come to the conclusion that the Zhenzhuyouxing apricot is a very strong drought resistance plant, and it is suitable to cultivating in the arid and poor mountain lands in North China.%用CIRAS-2便携式光合仪测定了不同土壤水分条件下(土壤相对含水量为84.7％～22.8％)2年生珍珠油杏叶片净光合速率、蒸腾速率、水分利用效率、胞间CO2浓度等光合生理参数的光响应过程,探讨其光合生理特性对土壤水分和光照强度的响应规律.结果表明:(1)随着土壤水分含量的降低,珍珠油杏叶片净光合速率、蒸腾速率、暗呼吸速率、光饱和点均呈降低趋势,表观量子效率先升高后降低,光补偿点先降低后升高.(2)利于珍珠油杏进行高光合作用并维持高水分利用效率的土壤相对含水量为43.6％～84.7％,适宜的光照强度为800～2 000μmol·m-2·s-1,即珍珠油杏对土壤水分和光照强度适应范围较广.(3)在土壤相对含水量43.6％～73.5％范围内,气孔限制是导致珍珠油杏光合速率下降的主要原因,在低于43.6％范围内,非气孔限制是导致光合速率下降的主要原因.研究认为,珍珠油杏是一种抗旱性比较强的植物,适合在华北干旱瘠薄山地引种栽培.
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