玉米根系形态性状和空间分布对水分利用效率的调控  

The effect of root morphological traits and spatial distribution on WUE in maize

作　　者：慕自新[1] 张岁岐[1] 郝文芳[1] 梁爱华[1] 梁宗锁[1] 

机构地区：[1]西北农林科技大学生命科学学院中国科学院,水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《生态学报》2005年第11期2895-2900,共6页Acta Ecologica Sinica

基　　金：中国科学院知识创新工程重要方向资助项目(KZCX3-SW-444);国家自然科学基金资助项目(30170559);西北农林科技大学青年基金资助项目~~

摘　　要：玉米根系形态性状(总根长、根系表面积和根系干物质重)与植物整体水分利用效率间具有显著或极显著的相关性,回归曲线趋势基本相同,均呈二次曲线关系,只是相关系数不同。说明从提高水分利用效率来说,根系需要维持适宜的大小。其中根长对水分利用效率的贡献是第一位的,而根系干物质重的贡献最小,根系表面积介于二者之间。从空间分布来说,玉米每层节根数、节根长度和直径在父母本和杂交种间也具有显著或极显著的差异。与中下层根量相比,母本与不抗旱的父本处于上层干土中的根系数量明显较多,且根系直径大,吸水困难。而杂交种在干旱条件下上层根重和数量维持不变,或略高于不抗旱品种,但中层和下层根系数量和长度明显高于不抗旱品种,且根系直径小于不抗旱品种,这样从多的有效根系数量和低的吸水阻力两方面保证了水分的吸收,从而使其产量和水分利用效率均最高,说明通过根系形态特性和空间分布的优化能够调节作物整体的水分利用效率。As water resources for agronomic use and the potential of engineer water-saving become more limiting, the improvement of water use efficiency （WUE） for plant themselves becomes increasingly more important. Root systems obviously play an important role in water acquisition for plants and are a significant component of tolerance to water-deficit stress. Yet, it is unclear what correlation exists between roots themselves and water use efficiency. We used three maize （Zea Mays L. ） varieties, HD4 （F1）,478（ ♂）and TS（♀） to study the relationship between various root characteristics and WUE under potted conditions conducted in a rainout shelter. The results indicated that there was a significant relationship between root characteristics and WUE. Regression analysis of WUE and total root length （TRL）, root system surface area （RSA） and total root biomass （RBM） presented parabola relation. Their trends were basically similar. When TRL, RSA, and RBM were small, then WUE increased as root size increased. However, when those parameters increased to a certain value, WUE began to drop, which suggested that root systems should maintain a suitable size in order to have a high WUE. The greatest WUE occurred when RSA,TRL and RBM were 4714 cm^2, 1. 118 ×10^5cm and 22. 8g,respectively. Among the root characteristics that were analyzed, TRL had the largest effect on WUE（r=0. 9312,p〈0.01）, RBM had the smallest effect （r=0. 7141, p〈0.05）, and RSA was intermediate （r=0. 9055, p〈0. 01）. WUE was also affected by the root spatial distribution pattern along the axis of the root systems. Varieties 478 and TS had more large diameter roots in the dry, upper layer of the soil compared to the middle and lower layers. This led to a reduction in water absorption. In contrast, the HD4 had more roots in the middle and lower layers of the soil. Total root length of HD4 was also larger in the middle and lower levels, but root diameter was smaller. The overall result was that HD4 had a more eff

关 键 词：玉米 根系形态特征 空间分布 水分利用效率 

分 类 号：S513[农业科学—作物学]