不同水量交替灌溉对小桐子生长调控与水分利用的影响

为研究不同水量交替灌溉对小桐子生长调控与水分利用的影响。采用4种水分处理模式(灌水定额分别为T1处理:10mm;T2处理:20mm;T3处理:30mm;T4处理:10和30mm,均不断的对2种灌水定额进行轮回交替)。结果表明:T1处理能在灌水定额为10mm,灌水周期为7d的环境下存活,表现出极强的抗干旱胁迫能力,其原因不仅是通过停止生长和叶片脱落适应干旱环境,而且最主要的原因是通过木质部有类似海绵状的物质能储存较多的乳白色的液体而继续存活。在节水21.6%前提下,与T3处理相比,T4处理的平均外皮层厚度显著增加了24%,叶片、叶柄、主杆、冠层和整株的单位干物质质量的贮存水能力分别显著增加28.3%、28.8%、13.7%、17%和12.3%,平均蒸散量和蒸腾量分别显著降低36.8%和20.4%,而根系和总干物质质量分别增加21.3%和1.3%,因此,总水分利用效率显著提高30.2%。可见,采用灌水定额为10和30mm交替灌溉的T4处理增强了贮存水调节能力,提高了小桐子的根系和总干物质质量,而降低了蒸腾量和蒸散量,从而使得水分利用效率显著提高。

Effects of alternated different irrigation amount modes on growth regulation and water use of Jatropha curcas L.

A pot-grown Jatropha curcas L.experiment was conducted to investigate the effects of alternated different irrigation amount modes on growth regulation and water use efficiency.Four watering treatment mode were designed in pot experiment,i.e.T1(every time irrigation amount for 10mm),T2(every time every time irrigation amount for 20mm),T3(every time every time irrigation amount for 30mm),T4(repeated alternate two kinds of combined irrigation amount as 10mm or 30mm).Result show that:1) Jatropha curcas L.can live in the environment where irrigation amount was 10 mm and irrigation cycle was 7 d,it was thus clear that it showed great resistance ability to drought stress under T1 treatment,the reason for continue to live and adapt to drought environment was not only by stopping growth and fall off more leaves,but the main reason was that the xylem have similar spongy material can storage more ivory liquid;2) compared to T3 treatment,T4 treatment saved irrigation water by 21.6%,mean significantly increased the cortex thickness by 24%.Meanwhile,T4 significantly increased WSC leaf,WSC petiole,WSC master rod,WSC canopy and WSC whole plant by 28.3%,28.8%,13.7%,17% and 12.3%,respectively.However,T4 treatment significantly reduced the evapo-transpiration quantity and transpiration by 36.8% and 20.4%,respectively,but increased mean the root mass and total dry mass by 21.3% and 1.3%,respectively,thus significantly increased total water use efficiency by 30.2%.Therefore,T4 treatment realized the optimal allocation of water supply by constantly alternate watering quota for 10mm and 30mm,could increase water use efficiency and water storage capability of Jatropha curcas L.by increased root and total dry mass,and significantly reduced transpiration and evapo-transpiration.