A pot experiment was conducted to study the ecological significance of redundancy in tillers of winter wheat and effect of reducing redundancy on water use efficiency by clipping some tillers of winter wheat and simulating environmental disturbance at two growing stages (jointing stage and heading stage). Plants were subjected to three treatments: (A) the main stem and the biggest tiller were retained, clipping all other tillers at jointing stage; （B）all small tillers were retained, clipping main stem and two bigger tillers at jointing stage; （C）all barren tillers were retained, clipping main stem and fertile tillers at heading stage. The undisturbed plants were considered the controls (CK). At flowering stage, the chlorophyll content, chlorophyll fluorescence parameters, stomatal conductance and transpiration rates were measured to evaluate the physiological and biochemical activity of winter wheat. The results showed physiological and biochemical activity of barren tillers could restore to the level of fertile shoots after clipping the main stem and big tillers. It is clear that barren tillers can afford to supplement and substitute for fertile shoot in physiological and biochemical activity at flowering stage. At maturity, although the uniform degree of plant height and spike weight, spike number and grain yield decreased significantly, which had no influence on propagation of the next generation. Therefore, tillers redundancy ensured that the disturbed plant can propagate and decrease the risk of plant extinction. After clipping barren tillers, the yield was unaffected, but water use efficiency for grain yield increased by about 10% compared to the control. It is shown that tiller redundancy is unfavorable to water use efficiency while reducing redundancy by taken some suitable agricultural measures is helpful to improve water use efficiency of crop.
全 文 ：