【摘要】 以杨树品种中嘉2号(Populus deltoides cv.Zhongjia No.2)和中石2号(P.deltoides cv.ZhongshiNo.2)为供试材料,采用Li-CoR-6200便携式光合仪测定它们在干旱胁迫时的净光合速率(Pn)及影响净光合速率的主要因子。结果表明,2个杨树品种对干旱胁迫的响应有相同的趋势,但在响应程度上存在一定的差异。中午干旱、光照强度大于等于1 270mol/(m2.s)条件下,2个品种均发生了光合作用的光抑制或光呼吸,其净光合速率均受到干旱的不利影响,但中石2号由于气孔导度(Gs)较大、羧化效率(CE)较高,这些内在遗传特性造成了中石2号的光合活性大于中嘉2号,从而使中石2号表现出较强的抵抗干旱胁迫的能力。更多还原

【Abstract】 Two poplar varieties Populus deltoides cv.Zhongjia No.2 and P.deltoides cv.Zhongshi No.2 were used as the experimental materials and the net photosynthetic rate(Pn) and other factors affecting it were measured using Li-CoR-6200 portable photosynthesis system under drought stress.The results demonstrated that two varieties showed similar response trend,but different response intensity to drought stress.Light inhibition or light respiration might occurred in both bleedings when light intensity was equal or greater than 1 270 mol/(m2·s),Pn was also negative influenced by drought.The results also showed that stomata conductance(Gs) and carboxying efficiency(CE) of P.deltoides cv.Zhongshi No.2 were bigger than that of P.deltoides cv.Zhongjia No.2.These innate heredity characteristics in P.deltoides cv.Zhongshi No.2 made it had higher photosynthesis activity than that in P.deltoides cv.Zhongjia No.2,witch indicated that Zhongshi No.2 had the stronger ability to resist the drought stress.更多还原