土壤水分亏缺对春小麦根系干物质累积和分配的影响

THE EFFECT OF SOIL WATER DEFICIENCY ON THE ACCUMULATION AND ALLOCATION OF ROOT BIOMASS OF SPRING WHEAT

在人工气候室中进行实验，实施光、温自动控制，研究了土壤水分对春小麦根系干物质积累和分配的影响，３个处理是春小科整个生长发育期内土壤水分分别控制在田间持水量的３０％，６０％，９０％，实验结果表明，在四叶一心－抽穗开花期间，３个处理气孔阻力逐渐降低，光合速率蒸腾速度逐渐上升，其中，中等水分条件下蒸腾速率明显低于充分供水，而光合速率则接近或显著高于是。抽一开花期，下层以根长。

An experiment was conducted in a plant growth chamber,in which light and temperature were controlled automatically. The soil water content was controlled to 30% (SD),60%(LD) and 90%(CT) of the field watercapacity.This experiment indicated that from the seedling stage to the heading and flowering stage,stomatal resistance in all treatments decreased,but the rate of photosynthesis and transpiration increased gradually.The rate of photosynthesis in LD treatment was similar to or significantly higher than that in CT,but the rate of transpiration in the former was significantly lower than that in the later.From heading stage to flowering stage,root length and root weight in the deeper soil layer in LD treatment were significantly higher than those in the other two treatments, although root length in the upper layer was no significantly different among three treatments, but root weight in the upper layer was higher in the treatment with higher soil water content.All these results show that LD treatment is favorable to a deeper root system.It will be helpful to use soil water in the deeper layer,tap productivity and yield potential.