土壤水分亏缺对冬小麦根系的影响

Effects of Different Soil Water Deficits on Roots of Winter Wheat

为给小麦高产稳产栽培提供依据,利用桶栽试验方法,通过人工调节土壤含水率形成4个水分梯度,即土壤水分含量分别占田间最大持水量的75%-80%(CK)、65%-70%(T1)、55%-60%(T2)和45%-50%(T3),研究了土壤水分亏缺对冬小麦根系的影响。各生育时期冬小麦单株平均次生根数随含水率的减少而减少,但不同生育时期水分亏缺对发根数的影响差异很大。拔节-孕穗期土壤水分亏缺引起次生根数的差异最明显,T1、T2、T3的次生根数分别只有CK的79%、70%、62%;抽穗-开花期的影响其次,T1、T2、T3的次生根分别为CK的82%、70%、64%;灌浆-成熟期的影响最小,分别为CK的97%、93%和89%。冬小麦根系在生育前期比生育后期对水分适应能力强。分蘖期水分亏缺处理对根系干重的影响不显著,拔节-孕穗期和抽穗-开花期根系干重受水分的影响达到极显著水平。拔节-孕穗期的水分亏缺处理对根系伸长有益,其中以轻度水分亏缺处理(T1)的伸长作用最强;抽穗-开花期水分亏缺处理也有助于根系伸长,但轻度水分亏缺处理(T1)对根系的伸长作用最弱。

The influence of different percentage of soil moisture 75 %- 80 % （ CK）, 65 %- 70 % （ T1 ）, 55%-60%（T2）,45%-50%T3） on winter wheat roots was studied by using pot experiment. The average numbers of secondary radical of wheat reduced with the decrease of soil moisture percentage in every growing stage. In jointing-booting stage, the average number of secondary radical per plant under the treatments of T1 ,T2 and T3 is 79%, 70%,62%of that under CK; and in heading-flowering stage, it is 82%,70%,64% of that under CK; and in grain-filling harvest stage, it is 97%,93%,89% of that under CK, respectively. The adaptation of roots in the earlier growing stage is better than in the later growing stage. In the tillering stage, the difference among treatments of water deficit are not remarkable on roots. But in jointing-booting stage and heading-flowering stage, the influence on roots among water deficit treatments are significant. Water deficit is benefit for the elongation of roots in jointing-booting stage and heading-flowering stage. The roots of T1 treatment is the longest in jointing-booting stage and the shortest in heading-flowering stage.