土壤水分对冬小麦根、冠干物质动态消长关系的影响

 在不同供水条件下 ,研究了冬小麦根、冠干物质积累的动态消长关系。结果表明 ,在水分胁迫条件下 ,冬小麦根系的干物质积累受到了明显的影响 ,40 %田间持水量处理植株的最终根重平均不到 80 %田间持水量处理的1/ 4。三叶期至分蘖期水分胁迫对根的抑制作用最大 ,拔节期至孕穗期水分胁迫对冠的抑制作用大于根 ,从分蘖期开始并延续到孕穗阶段的水分胁迫对根和冠的抑制作用较均衡 ,复水后干物质向根系和冠层的分配比例近似。拔节期至孕穗期复水对根的促进作用大于冠 ,干物质向根分配的比例增加 ,R/S提高 ,但提高的程度与复水前水分胁迫的历时有关。水分条件对冬小麦R/S值影响最小的时期是开花期至灌浆期 ,最大的时期是拔节期至抽穗期 ,此阶段 40 %田间持水量处理的R/S分别比 60 %和 80 %田间持水量处理提高 2 0 .93 %和 12 6.0 9%。

Effects of Soil Moisture on Dynamic Distribution of Dry Matter in Winter Wheat Root and Shoot

The dynamic relationship of dry matter accumulation a nd distribution in winter wheat root and shoot were studied under different soil w ater conditions. The dry matter accumulation in root was greatly influenced by water stress, so as to the final root weight of the treatment with 40% field moi sture capacity(FMC) was less than 1/4 of that of the treatment with 80% FMC on a verage. Water stress during the 3-leaf stage to the tillering stage had a great est influence on root, and the influence of water stress during the jointing sta ge to the booting stage on shoot was greater than root. However, water stress du ring the tillering stage to the booting stage had a balanced effect on root and shoot, and the proportion of dry matter that distributed to root and shoot was a lmost the same after rewatering. Water recovery during the jointing stage to boo ting stage could promote R/S, but increasing degree related to the duration of w ater limitation. Soil water condition had the lowest effect on R/S during the fl owering stage to the filling stage and the maximal effect on R/S during the join ting stage to the heading stage, R/S of 40% FMC treatment was 20.93% and 126.09% higher than that of 60% FMC and 80%FMC, respectively , at this period.