不同土壤水分处理对冬小麦根冠生长的影响

Effect of different soil water conditions on growth of root and shoot of winter wheat

通过温室冬小麦不同水分处理(土壤含水量分别为田间持水量的75%～100%,65%～55%,35%～45%)盆栽试验,研究了冬小麦根冠对水分的响应。试验结果表明:不同供水量并不影响冬小麦根系、冠层干物质累积过程的总趋势,但随胁迫的增强,根、冠干物质累积速率、干物质累积总量降低,且二者并不呈线性相关关系;根冠比(R/S)随胁迫的增强而增大;水分供应量的减少缩短了冬小麦的生育周期,随胁迫的增强,根冠生物量最大值出现的时间提前;充分供水的处理则有最大的根冠比(R/S)。这可能是由于水分胁迫发生,大量的同化产物运往根系,分配于根系的同化干物质增加,调整了根系的结构,改善其功能以增大水分的吸收量,缓减植株由于缺水造成的损失,导致根系干重增加,根冠比增加。对于供水超过75%的植株,根冠比达到所有处理的最大,可能原因为过量水分促使庞大根系的建成,从而消耗较多的同化产物,使根重增加,冠重减少。

The pot experiments were conducted in greenhouse under three water conditions, that is, 75%~100%, 65%~75% and 35%~45% of field capacity, to analyse the effect of water conditions on the growth of root and shoot of winter wheat. The results indicate that root growth, shoot growth and the ratio of root/shoot (R/S) get, and the growth period becomes shorter when water supply is decreased although the general accumulative trend of root and shoot of winter wheat is not affected by different water conditions. The responses of root and shoot to the same water condition are not identical. Under the wellwatered treatment, the ratio of R/S is the largest, which may be caused by the building of extensive root system.\;