为筛选适宜北疆绿洲区滴灌春小麦高产栽培的水分管理模式,比较分析了耕层(0-40cm土层)不同墒度条件下滴灌春小麦旗叶SPAD值、灌浆期光合和荧光参数及产量的差异。结果表明,拔节至乳熟期土壤墒度过高或过低均会显著降低旗叶SPAD值(P〈0.05),乳熟期增加土壤墒度延缓了叶片衰老。在灌浆期,旗叶光合速率随土壤墒度的增加而显著提高;蒸腾速率在15∶00时T4处理(苗期-拔节、孕穗-乳熟和成熟-收获阶段耕层土壤平均含水量分别为田间持水量的75%、80%和65%)显著高于其他处理,高墒度处理T5(苗期-拔节、孕穗-乳熟和成熟-收获阶段耕层土壤平均含水量分别为田间持水量的80%、85%和70%)最低;气孔导度(Gs)在15∶00时显著降低后,在17∶00时又逐渐升高,且T4处理显著高于其他处理;胞间CO2浓度变化趋势同Gs一致;叶绿素荧光参数Fv/Fo、Fv/Fm、ΦPSⅡ等随土壤墒度升高而显著增加;土壤墒度较低处理的qP相对较低,NPQ较高;土壤墒度过高或过低均会降低小麦籽粒产量,产量构成中穗粒数对土壤墒度最敏感,千粒重次之。说明在本试验条件下,苗期-拔节、孕穗-乳熟和成熟期耕层土壤平均含水量分别占田间持水量的70%-75%、75%-80%和60%-65%是滴灌春小麦获得高产的最佳水分管理模式。
In order to explore the changes of the SPAD values,photosynthetic characteristics,chlorophyll fluorescence kinetics parameters and yield components under different soil moisture of drip irrigated spring wheat,field experiment was carried out in Northern Xinjiang.The results showed that the SPAD values was significantly reduced under higher or lower soil moisture treatments during jointing and milking stage(P〈0.05).However,the higher soil moisture delayed the leaf senescence during maturity.The net photosynthetic rate(Pn)of flag leaf increased as soil moisture raised within filling period.The transpiration rate(Tr)was significantly greater than at other treatments at 15∶00 in T4treatment which was the second highest soil moisture(P〈0.05),however,Trunder T5which was the highest soil moisture was the lowest.The values of stomatal conductance(Gs)was the lowest at 15∶00and increased gradually at 17∶00under different treatments,which of T4was much higherthan others.Variation trends of intercellular CO2concentration(Ci)were similar to Gsin different treatments.Chlorophyll fluorescence kinetics parameters such as Fv/Fo,Fv/Fm,ΦPSⅡof spring wheat flag leaf increased as soil moisture raised.Photochemical quenching(qP)was the lowest while Non photochemical quenching(NPQ)was the highest under lower soil moisture.When soil moisture was suitable during spring wheat growth stages,grain yield could be higher,and among yield components,grain number of spike was influenced much more than 1000-grain weight.Therefore,the results revealed that the optimal water management pattern was the soil moisture of 70%-75%at seedling-jointing,of 75%-80%at booting-milking,of 60%-65%at maturity.