干旱胁迫对冬小麦根系生长及营养代谢的影响

研究了不同程度土壤持续干旱对冬小麦根系生长及营养代谢的影响。结果表明，干旱胁迫使小麦次生根发育迟缓，数量减少，根系发硬，根尖萎缩，拔节至扬花阶段对发根潜能的影响最大。根系干物质积累量减少，峰值延后；根系中氮、磷积累量下降，分配比例在生殖胁迫有较多的氮、磷损失；根系中的含量下降，Ｃ／Ｎ失调。维持根系对氮、磷良好吸收、分配、运转和Ｃ／Ｎ协调的土壤含水量不能低于６０％。

Effects of Drought Stress on Roots Growth and Nutrient Metabolism of Winter Wheat

The effect of roots growth and nutrient metabolism of winter wheat was studied under different degree of soil sustaining drought. It showed that under the drought stress condition the secondary roots develop slowly, the amount of those decreased, roots were harden, root tip shrink back. Rooting ability was effected badly in jointing flowering stage. The roots dry matter accumulation also declined, the peak appearance was delayed. The total accumulation of N and P decreased. The distribution ratio of accumulation declined at the early and middle stages, then rises after flowering. More N and P stayed in the roots at the late stage, less was transported outward, and to lose more above middle degree drought stress. The content of total soluble sugar decreased, and the ratio of C to N is disorder. The content of soil water which maintain the roots uptake and transport N,P well and form the appropriate ration of C to N can't be less than 60% percent.