局部根区灌溉对棉花主要生理生态特性的影响

Growth and Allocation of Photosynthetic Produces in Cotton Under Alternative Partial Root-Zone Irrigation

【目的】探讨局部根区不同灌溉模式对棉花主要生理生态特性的影响。【方法】以盆栽棉花为试验材料,比较分根交替灌溉(APRI)、分根固定灌溉(FPRI)和常规灌溉(CK)下,棉花的生长、光合产物分配及相关生理响应。【结果】当灌溉量减少50%时,APRI处理的总生物量仅比CK降低10%左右,而FPRI则降低23%。不同处理的根系总量虽无差别,但APRI和CK处理的吸收根干重明显高于FPRI;APRI的根系分布与CK基本一致,FPRI处理未灌溉一侧的吸收根数量则显著低于灌溉一侧。分根灌溉条件下,棉株的叶片与木质部汁液ABA浓度大幅增加,调控气孔运动,减少蒸腾耗水。【结论】分根交替灌水能刺激棉株吸收根生长,有效调节同化产物在根冠间的比例和分配,是一种切实可行的节水灌溉方式。

[Objective] The objective of this experiment is to study the effect of alternative partial root-zone irrigation on the physiological and ecological characters of cotton. [Method] With pot-grown cotton plants, the current study compared the physiological effects, growth and allocation of photosynthetic produces under alternative partial root-zone irrigation （APRI）, fixed partial root-zone irrigation （FPRI）, and conventional full root-zone irrigation （CK）. [Result] It was found that with 50% reduction in the amount of irrigation as compared with CK, biomass in APRI reduced by only 10%, while in FPRI the reduction was 23%. The results also revealed that although the total amounts of root biomass were the same in every treatment, the root/shoot ratio in APRI and FPRI increased significantly. Further analysis revealed that, the total amount of absorbing roots in CK and APRI were approximately the same, but higher than in FPRI in both cases. With partial root-zone irrigation, ABA content in leaves and stems increased significantly, which regulated the water loss through adjusting stomatal opening. [Conclusion] Results show that APRI could stimulate the growth of absorbing roots, adjust allocation of photosynthetic produces between shoots and roots, therefore it is a promising irrigation method for saving water and keeping reasonable crop product.