干旱胁迫下氮素对胡杨幼苗生长及光合的影响  

Effect of nitrogen on growth and photosynthesis of Populus euphratica seedlings under drought stress

作　　者：钟小莉[1] 马晓东[1,2] 吕豪豪 朱成刚[2] 杨余辉 ZHONG Xiao-li MA Xiao-dong LU Hao-hao ZHU Chen-gang YANG Yu-hui(College of Life Science, Xinjiang Normal University, Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, Urumqi 830054, China State Key Laboratory of Desert and Oasis Ecology, Institute of Ecology and Geography, Urumqi 830011, China)

机构地区：[1]新疆师范大学生命科学学院新疆特殊环境物种保护与调控生物学实验室,乌鲁木齐830054 [2]荒漠与绿洲生态国家重点实验室,乌鲁木齐830011

出　　处：《生态学杂志》2017年第10期2777-2786,共10页Chinese Journal of Ecology

基　　金：中国科学院西部之光项目(2015-XBQN-A-09);国家重点实验室开放课题(GZS-2015-03);国家科技支撑计划课题(2014BAC15B02);新疆师范大学硕士研究生科技创新项目(XSY201602004)资助

摘　　要：胡杨(Populus euphratica)是塔里木河流域荒漠河岸林重要的抗逆种质资源,胡杨幼苗的存活及生长受水分和氮素的限制。为了研究干旱胁迫下氮素供应对胡杨幼苗早期形态建成的影响,本试验以1年生胡杨实生幼苗为研究对象,采用温室盆栽试验,设置4个水分处理(D_1、D_2、D_3、D_4,土壤含水量为20%~25%、40%~45%、60%~65%、80%~85%)和3种施氮水平(N_0、N_1、N_2:0、3、6 g·pot-1),测定胡杨幼苗的生长指标、叶绿素荧光和光合参数。结果表明:轻度干旱胁迫(D_3)下,施氮量为N_1时,胡杨幼苗的表观生长和光合能力显著提高;幼苗根冠比在D_1时最低,施氮使其显著增大;干旱胁迫(D_1、D_2、D_3)下,N对幼苗生长的促进作用大于N_2;严重干旱胁迫(D_1)时,施氮显著提高幼苗荧光参数和光合速率,增强其光合能力;因此,胡杨幼苗在土壤相对含水量60%~65%(D3)、氮素量为3g·pot^(-1)(N_1)时,其生长表现为最佳状态;干旱胁迫下,氮素能显著增强幼苗地下部分生长和光合能力,表明氮素对干旱胁迫具有补偿效应,可促进幼苗的早期形态建成,有效帮助幼苗渡过生长脆弱期。Populus euphratica is an important stress-resistant germplasm resource for desert riparian forests in Tarim River Basin.The survival and growth of P.euphratica seedlings are always limited by water and nitrogen.In this experiment,we studied the effect of nitrogen supply on the early morphogenesis of P.euphratica seedlings under drought stress.Four water treatments（D1,D2,D3 and D4 with soil relative water contents of 20%-25%,40%-45%,60%-65% and 80%-85%,respectively） and three nitrogen application levels（N0,N1,N2：0,3,6 g·pot^-1） were used to determine the growth index,chlorophyll fluorescence and photosynthetic parameters of P.euphratica seedlings.The results showed that under slight drought stress（D3）,P.euphratica seedlings had a higher capacity of growth and photosynthesis when N1 was applied.Under severe drought stress（D1）,the root/shoot ratio of seedlings was the lowest,and significantly increased when the nitrogen level increased.Under the conditions of drought（D1,D2,D3）,the effect of N1 on seedling growth was higher than that of N2.Under severe drought stress（D1）,nitrogen application significantly increased the fluorescence parameters and photosynthetic rate.Therefore,P.euphratica seedlings had the best growth performance when soil relative water content was 60%-65%（D3） and nitrogen application level was 3 g·pot^-1（N1）.The root growth and photosynthetic capacity of seedlings was significantly increased by nitrogen fertilization under different drought stresses,indicating that nitrogen had a compensatory effect on drought stress.So,nitrogen fertilization can promote the early morphogenesis of P.euphratica seedlings and help the seedlings survive during the vulnerable period of growth.

关 键 词：胡杨幼苗 氮素 干旱胁迫 叶绿素荧光 光合 

分 类 号：S792.11[农业科学—林木遗传育种]