摘要：以秦豆8号为材料进行盆栽试验,研究了大豆苗期、花期及结荚期不同土壤控水处理对大豆结荚期光合生理和生物量的影响.结果表明:当苗期-花期前土壤相对含水量控制为65％～75％情况下,在花期分别进行轻度(土壤相对含水量控制为55％～65％)、中度(土壤相对含水量控制为45％～55％)水分胁迫,结荚期复水至正常供水后,与对照(大豆不同生长阶段土壤相对含水量均保持为65％～75％)相比,随胁迫程度的加剧光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)降幅加大,中度胁迫下分别降低13.16％(P＜0.05)、28.60％(P＜0.01)、7.64％、49.51％(P＜0.01),而气孔限制值(Ls)、叶片温度(T1)较对照有所提高,中度胁迫下分别提高48.07％(P＜0.01)、0.36％；当苗期-花期正常供水结英期分别进行轻度、中度胁迫时,Pn、Tr、Ci、G较对照均降低,而Ls及T1较对照提高.当苗期-花期前土壤相对含水量控制为55％～65％情况下,在花期或结英期进行中度胁迫均使Pn、Tr、Ci、Gs降低,Ls及T1升高,复水后则反之.当苗期-花期前土壤相对含水量为45％～55％时,不论花期或结荚期进行正常供水或轻度胁迫,各处理Pn、Tr、Ci、Gs均高于对照(大豆不同生长阶段土壤相对含水量均保持为45％～55％),而Ls及L1低于对照.当苗期—结荚末期土壤相对含水量连续控制在3个水平条件下,随土壤含水量的降低,Pn、Tr、Ci、Gs呈下降趋势,而Ls及T1升高.当苗期-花期前分别进行正常供水、轻度胁迫、中度胁迫控水处理时,不同处理结荚期单株生物量呈显著差异,中度胁迫与轻度胁迫各处理的单株生物量差值小于正常供水与轻度胁迫各处理单株生物量差值.%A study was conducted on the effects of water stress and re-watering on photosynthesis and biomaas of soybean (Qin Dou NO.8) under different soil water treatments during the stages of seedling, blooming and pod-setting. The low-grade (55% ~ 65%) and middle-grade (45% -55%) water stress was controlled respectively at blooming stage, with relative soil water content of 65 % - 75 % from seedling to early blooming stage. The results showed that Pn , Tr, Ci and Gs declined extremely with the stress increasing, and reduced respectively by 13.16% , 28.60% , 7.64% and 49.51 % under middle-grade stress compared with CK (65 % ~ 75 % ), while Ls and T, improved by 48.07 % and 0.36% separately. When soil water content was remained at 65% - 75% from seedling to blooming stage, and low-grade and middle-grade water stress was controlled respectively at pod-setting stage, Pn, Tr, Ci and Gs decreased compared with CK (65% -75%) , while Ls and T1 increased. When soil water was remained at 55% - 65% from seedling to the early blooming stage, and the middle-grade water stress was controlled at blooming or pod-setting stage, the results showed that Pn, Tr, Ci and Gs decreased, but Ls, T1 increased compared with CK (55% ~65%); while soil water was turned to 65% ~ 75% at blooming or pod-setting stage, the photosynthesis parameters above showed adverse situation compared with middle-grade water stress treatments. When soil water content was remained at 45% ~ 55% from seedling to the early blooming slage, and soil water was remained at 65% - 75% or low-grade water stress was controlled in blooming or pod filling stage, the results showed that Pn, Tr, Ci and Gs improved compared with CK (45% ~ 55 % ), but is and T^ decreased. When the relative soil water content from seedling to end of pod-setting stage was 65% ~ 75% , 55% ~ 65% and 45% ~ 55% , respectively, Pn, Tr, Ci and Gs showed a declining trend with the soil water content decreased, while Ls, T1 showed an ascendant trend. The difference of plant biomass between middle-grade and low-grade water stress treatments was less than that between normal water treatment and low-grade water stress.