在干旱的影响下,较年轻的上端器官,如穗、上茎、旗叶鞘、旗叶能够较久地保持稍好的水分供应,以维持其生理功能。干旱通过水分胁迫的直接影响和促进早衰而减低植物的光合能力,并因同化产物供应不足,使粒重降低导致减产。灌浆前半期经受于旱的处理,因光合产物损失多、减产较多。但在同化产物供应不足的情况下,被利用于充实籽粒的贮存物质的数量则有所增多。中度到近于严重的水分胁迫并不妨碍筛管中物质运输。相反,却因为促进早衰而使叶、茎中所含的氮、磷和糖加速运出。运入每穗籽粒中的氮素和对照近似,磷则明显减少。 讨论了小麦对花后土壤干旱的保护性适应。 Under the influence of drought, younger upper organs, such as ears, upper stems, flag leaf sheaths and flag leaves, can maintain a slightly better moisture supply for a long time in order to maintain their physiological functions. Droughts reduce the photosynthetic capacity of plants through the direct effects of water stress and promote premature aging and reduce production due to under-supply of assimilation products. The first half of grouting suffered drought treatment, due to the loss of photosynthetic products and more yield reduction. However, in the case of inadequate assimilation products, there is an increase in the amount of stored substances utilized to enrich the grain. Moderate to near-severe water stress does not prevent material transport in the screen. On the contrary, the nitrogen, phosphorus and sugar contained in the leaves and stems are expelled expeditiously because of the promotion of premature aging. Nitrogen transfered into grains per panicle was similar to the control and phosphorus was significantly reduced. The protective adaptation of wheat to soil drought after anthesis was discussed.