限量灌溉对小桐子生长和水分利用效率的影响

摘要

A pot-grown experiment was conducted to investigate the effect of limited irrigation on growth,storage water amount and water use of Jatropha curcas L. seedlings. Four watering treatments were designed in the study,i. e. (W1:0. 3θf,W2:0. 5θf,W3:0. 7θf and W4:0. 9θf,θf is the field capacity). Results show that Jatropha curcas L. seedlings has the higher resistance ability to drought-stress,it can survival in lower soil moisture (0. 3θf). Storage water capability of unit dry mass shows that petiole>branch and master rod>leaf>root. Compared to W4 treatments,W2 reduces irrigation water by 29. 09%,mean leaf area reduces by 25. 8%,but root-shoot ratio increases by 6. 1%,and the mean storage water capability of unit root,lateral branch and master rod,leaf,shoot and total plant dry mass increase by 15. 4%,1. 3%,7. 4%,0. 6% and 1. 8% respectively. But the mean root and shoot dry mass accumulation reduce by 11. 4% and 17. 7%respectively. Therefore,irrigation water use efficiency and total water use efficiency of Jatropha curcas L. seedlings increase by 15. 5% and 14. 9% respectively. It is clear that W2 treatment has the higher water use efficiency and storage water capability,thus Jatropha curcas L. seedlings can improve water regulation and control water balance capability and resistance ability to drought-stress.%为探索限量灌溉对盆栽小桐子幼树生长、各器官贮水能力和水分利用的影响，进行了4种灌水处理（W1：0．3θf；W2：0．5θf；W3：0．7θf；W4：0．9θf。θf为田间持水量）的盆栽试验。结果表明：小桐子能在较低土壤水分（0．3θf ）下存活，具有较强的抗旱性。各器官单位干质量的贮水能力表现为叶柄＞带侧枝主秆或冠层＞叶片＞根系。与W4处理相比，在W2处理节水达29．09％，其平均叶面积下降25．8％，而根冠比增大6．1％，根系、带侧枝主秆、叶片、冠层、全株的贮水能力分别提高15．4％、1．3％、7．4％、0．6％、1．8％，根干质量、冠层干质量仅分别降低11．4％、17．7％，W2处理的平均灌溉水利用效率和总水分利用效率分别提高15．5％和14．9％。可见，W2处理不仅提高水分利用效率，而且促进贮水调节能力的提高，从而增强了调控小桐子幼树体内水分平衡和抗干旱胁迫的能力。