水分胁迫对冬小麦物质分配及产量构成的影响

Effect of Water Stress on Dry-matter Partition and Yield Constitution of Winter Wheat

通过设置不同土壤水分条件和不同生育期受旱处理,研究土壤水分条件对冬小麦生长发育的影响。从器官水平上详细考察了水分条件对小麦物质积累、分配以及产量的影响,并建立产量和耗水量关系。在相对适宜的土壤水分条件,茎秆所占比例较小,为24%,穗部则占56%;而过度灌溉和水分亏缺条件下,茎秆所占比例较大,分别为36%和37%,穗部比例相对较小,仅为43%和48%。各种条件下均以茎秆对产量的贡献量大。相对适宜的土壤水分条件,茎秆对产量的贡献量最大,为0.308g/茎;水分亏缺条件下,叶鞘对产量贡献量较适宜土壤水分条件的叶鞘贡献量要大,分别为0.18克/茎和0.09克/茎;而过度灌溉条件下各器官对产量的贡献量均较小。根据实测产量和蒸散耗水量模拟的产量、水分利用效率与蒸散耗水量的关系可知:禹城地区在现有的肥力水平和栽培管理措施下冬小麦的理论最大产量为6240kg/hm2,蒸散耗水量为473mm,而获得最高水分利用效率的蒸散耗水量为403mm。由于该地区地下水埋深浅,地下水对冬小麦生育期需水量的补给作用明显,试验年份冬小麦拔节期至成熟期地下水补给量占同期耗水量的22%。

Dry-matter accumulation,partition and yield of winter wheat by different irrigation or water stress in different development stages was analyzed.The proportion of stem was low and the proportion of spike was high under the fitting water condition,there were24%of stem and56%of spike.But on the condition of water stress,the proportion of stem became higher and the proportion of spike was lower.On condition of water shortage,the proportions of stem and spike were36%and43%respectively,and on the redundant water condition,the proportions were37%and48%.The contribution from stem to yield was0.308g/stem under the fitting wa-ter condition;on the condition of water shortage the contribution from sheaths to yield was high-est in treatments,was0.18g/stem.The relationship between yield and evapotranspiation indicat-ed that the highest theoretical yield was6240kg/hm 2 in Yucheng under present fertilizer and management level.The evapotranspiration at highest yield was473mm;and the evapotranspira-tion was403mm when water use efficiency was highest.Groundwater was an important water resource in this area.Amount of water supplied by groundwater to wheat from jointing to maturi-ty stages was22%of total water consumption of winter wheat.