干旱胁迫对不同施氮水平麻疯树幼苗光合特性及生长的影响  

Effect of drought stress on photosynthetic characteristics and growth of Jatropha curcas seedlings under different nitrogen levels

作　　者：尹丽[1] 胡庭兴[1] 刘永安 姚史飞[1] 马娟 刘文婷[1] 何操[1] 

机构地区：[1]四川农业大学林学院四川省林业生态工程重点实验室,四川雅安625014 [2]凉山州林业科学研究所,四川西昌615021 [3]阆中市林业局,四川南充637400

出　　处：《应用生态学报》2010年第3期569-576,共8页Chinese Journal of Applied Ecology

基　　金：中日技术合作四川省示范林营造项目(JICA);四川农业大学2008年国家级大学生创新性实验计划项目(2008-17)资助

摘　　要：采用盆栽控水的方法,研究了干旱胁迫(连续干旱0d,5d,10d,…,45d)对不同施氮水平(对照0kgN.hm-2、低氮96kgN·hm-2、中氮288kgN·hm-2、高氮480kgN·hm-2)麻疯树幼苗光合特性及其生长的影响.结果表明:随干旱胁迫强度的增加,各施氮水平麻疯树幼苗叶片相对含水量、苗高生长量、地径生长量、叶面积、净光合速率、蒸腾速率和气孔导度均降低,且各水分处理间差异极显著(P<0.01);随干旱时间的延长,叶绿素含量和水分利用效率表现出先升高后降低的趋势,而胞间CO2浓度呈先降低后升高的趋势.正常供水时,施氮处理均不同程度提高了麻疯树幼苗的光合能力,促进了麻疯树幼苗的生长,且施氮量越高效果越好;干旱条件下,氮素营养对植株光合能力和生长的影响与干旱程度和施氮水平有关.轻度干旱时,提高施氮水平对植株光合能力和生长具有明显的促进作用;中度干旱时,中氮的促进作用明显高于其他施氮水平;严重干旱时,低氮的促进效果最好,高氮的促进作用减弱并逐渐转向抑制.A pot experiment with controlled water supply was conducted to study the effects of drought stress （continuous drought for 0 d, 5 d, 10 d, …, 45 d） on the photosynthetic characteristics and growth of Jatropha curcas seedlings under different nitrogen fertilization levels （N0, 0 kg N·hm^-2; NL, 96 kg N·hm^-2; NM, 288 kg N·hm^-2; NH, 480 kg N·hm^-2）. With the enhancement of drought stress, the leaf relative water content （RWCl）, height growth （Zh）, basal diameter growth （Zd）, leaf area （La）, net photosynthetic rate （Pn）, transpiration rate （Tr）, and stomatal conductance （Gs） decreased significantly （P〈0.01）, irrespective of nitrogen fertilization level. The chlorophyll （Chl） content and water use efficiency （WUE） increased first and decreased then, while the intercellular CO2 concentration （Ci） had an increase after an initial decrease. Under adequate water condition, nitrogen fertilization promoted the photosynthesis and growth of J. curcas seedlings to different degrees, and the effect was increased with increasing nitrogen fertilization level. Under drought stress, the effects of nitrogen nutrition on the photosynthesis and growth were dependent on drought intensity and nitrogen fertilization level. Specifically, increasing nitrogen fertilization level could promote the photosynthesis and growth of J. curcas seedlings under mild drought, the promotion effect of NM was higher than that of NL and NH under moderate drought, and NL had the best promotion effect while NH weakened the effect or made it negative under severe drought.

关 键 词：麻疯树 干旱胁迫 施氮 光合特性 生长 

分 类 号：S792.99[农业科学—林木遗传育种]