不同土壤水分冬小麦根、冠关系及其对叶片水分利用效率的影响

Relationships between root and shoot of winter wheat under different soil water conditions and their effects on the water use efficiency

  • 摘要: 试验研究不同土壤水分冬小麦根、冠关系及其对叶片水分利用效率的影响结果表明,水分条件对根系与叶冠间干物质分配模式影响较小,而对根系功能与叶冠结构建成之间关系影响较大,水分胁迫抑制植株结构的建成,随作物由营养生长向生殖生长的过渡其根系功能发挥与叶冠结构建成之间矛盾愈加明显,拔节期复水有利于植株根系功能的增强和叶冠结构的改善。根冠比与叶片水分利用效率关系呈单峰倒“V”型曲线,水分多少可影响曲线的斜率和高低。根量达最大值前沿根冠比降低的方向,叶片水分利用效率增加;当根量达最大值时叶片水分利用效率也达最大值,此时根冠比为0.1~0.2。而抽穗期后沿根冠比降低的方向,其叶片水分利用效率也降低。

     

    Abstract: Relationships between root and shoot of winter wheat under different soil water conditions and their effects on the water use efficiency of leaf(WUEL)were studied.The results indicate that the effect of soil moisture on the dry matter allocation pattern between root and shoot is little,but is great on the relationship between root function and shoot structure forming.Water stress inhibits the structure forming of plant,with the crop growing from vegetive period to reproductive period,the inconsistency between root function exerting and shoot structure forming is more and more distinct.Rewatering during the jointing stage is favorable to strengthen the function of root and improve the structure of shoot.The correlation curve between ratios of root and shoot(R/S)and WUEL is a single peak of inverse “V”figure,and water content can influence the slope and intercept of the curve.WUEL increases with the decreasing of R/S before the root biomass reaches its maximal value;WUEL arrives at the peak value when the root biomass reaches its maximal value,while the R/S is between 0.1 and 0.2.WUEL reduces with the minishing of R/S after the heading stage.

     

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