盐胁迫条件下不同水量交替灌溉对小桐子生长和水分利用的影响

Effects of alternative irrigation on growth and water use for Jatropha curcas L. under salt stress condition

为了研究盐胁迫条件下,不同水量交替灌溉对小桐子幼树生长和水分利用效率的影响,采取盆栽试验,设置3种供水水平[W1:19.8 mm,W2:19.8/39.6 mm(对2种灌溉定额进行交替灌溉),W3:39.6 mm]和3种施盐水平(每kg风干土中加入Na Cl分析纯的质量分别为S0:0 g,S1:3 g,S2:6 g),对小桐子幼树进行处理.结果表明:与处理W3相比,W2节水19.72%,其平均茎粗、叶面积及叶片数仅分别下降了4.10%,6.14%,1.32%,总蒸散量和干物质质量分别减少19.68%和10.14%,从而水分利用效率提高了11.61%.在处理W2下,与处理S0相比,S1的小桐子总干物质质量和水分利用效率分别显著增加17.49%和20.30%,表明在处理W2下,处理S1对提高小桐子的生长和水分利用效率具有一定的促进作用.盐分S2胁迫时,与处理W3相比,W2的株高和茎粗分别提高44.99%和3.47%,总蒸散量显著降低20.30%,总干物质质量和水分利用效率分别显著增加30.90%和65.38%,表明在盐胁迫程度较高的处理S2下,采用处理W2具有提高小桐子抗盐胁迫的能力.可见,在盐胁迫条件下采取不同水量交替灌溉处理,不仅可促进小桐子生长和水分利用效率提高,而且提高了小桐子的抗盐胁迫能力.

To investigate effects of alternative irrigation on growth and water use for Jatropha curcas L.under salt stress condition,three irrigation quotas( W1: 19. 8 mm,W2: 19. 8 /39. 6 mm,W3: 39. 6mm) and three salt contents( pure Na Cl) levels( S0: 0 g / kg,S1: 3 g / kg; S2: 6 g / kg) in the airdried soil are adopted in the pot-grown experiments on Jatropha curcas L.. Note that quotas 19. 8 /39. 6 mm are alternatively applied in case W2. The results show that in case W2 the irrigation water is saved by 19. 72% compared with case W3,but the stem diameter,size and number of leaves,evapo-transpiration and dry mass are decreased only by 4. 10%,6. 14%,1. 32%,19. 68% and 10. 14%,respectively,causing 11. 61% improvement in water use efficiency. In case W2,compared with S0 case,the dry mass and water use efficiency are increased by 17. 49% and 9. 95%,respectively,in case S1,indicating that case S1 is helpful for Jatropha curcas L. to grow and for water use efficiency to be improved. In salt stress case S2,compared with case W3,the plant height and stem diameter,dry mass and water use efficiency are increased by 44. 99%,3. 47%,30. 90% and 65. 38%,respectively,in case W2,and the evapotranspiration is decreased by 20. 30%,suggesting alternative irrigation can help Jatropha curcas L. to resist salt stress. Thus,it's clear that alternative irrigation is not only beneficial for Jatropha curcas L. growth and water use efficiency improvement under salt stress condition,but also helpful for Jatropha curcas L. to improve the ability to resist the salt stress.