摘要
利用开顶式气室和盆栽方法,以冬小麦品种"小偃6号"和"小偃22"为供试材料,在2种CO2浓度(375μL.L 1和750μL.L 1)和3个施氮水平[0、0.15 g(N).kg 1(土)和0.30 g(N).kg 1(土)]下分析了小麦抽穗期绿色叶片、非叶光合器官(茎鞘、穗、芒)的形态和光合面积以及粒叶比对CO2浓度升高和施氮的反应。结果表明,施氮有助于小麦叶和非叶光合器官伸长和增宽(粗),增加其光合面积、穗粒数、穗粒重、粒数叶比和粒重叶比。与背景CO2浓度(375μL.L 1)相比,CO2浓度升高对叶片和茎节长度、茎叶和芒光合面积具有明显的正向效应(P〈0.05),但对叶宽、茎节直径、穗面积影响不明显(P〉0.05),使"小偃6号"和"小偃22"单茎光合面积分别增加8.1%~15.1%和2.8%~13.2%,且均以0.30 g(N).kg 1(土)施氮水平下增幅最大。CO2浓度升高后,穗粒数和粒数叶比在3个施氮水平下均不同程度增加,其中2个品种粒数叶比分别在0.30 g(N).kg 1(土)和0.15g(N).kg 1(土)施氮水平下增加最明显,增幅分别为44.2%和41.4%;穗粒重和粒重叶比在不施氮时下降,在施氮时显著增加,其中2个品种粒重叶比平均增幅分别为43.6%和20.7%。由于芒面积远小于其他源器官面积,在单茎光合面积中所占比例较小(3%左右),因此认为CO2浓度升高主要通过促进小麦茎叶伸长生长来增加光合面积,同时提高单位叶面积库承载力和物质调运能力,改善源库关系,增加氮素供应有利于小麦源库生长对CO2浓度升高的反应。
Either CO2 enrichment or nitrogen(N) application influences growth and development of wheat(Triticum aestivum L.).The effects of elevated CO2 concentration and nitrogen addition on the photosynthetic area of source organs(green leaves,stem sheath,spike and awns),grain number and weight per spike,and grain-leaf ratio of winter wheat at heading stage were investigated in this study.The pot experiment was carried out in open top chambers(OTCs) with two wheat varieties,"Xiaoyan 6" and "Xiaoyan 22",as materials in 2008—2009.Wheat plants were grown under different treatments of two CO2 concentrations(375 μL.L 1 and 750 μL.L 1) and three nitrogen application levels [0,0.15 g(N).kg 1(soil) and 0.30 g(N).kg 1(soil)].The results showed that nitrogen application significantly increased leaf length and width,stem node length and diameter,spike length and width,awn length.The photosynthetic area,grain number and weight per spike,and grain-leaf ratio of wheat were also enhanced under nitrogen application.Compared with ambient CO2 concentration(375 μL.L 1),elevated CO2 concentration(750 μL.L 1) positively influenced leaf and stem node length,photosynthetic area of leaf,stem node and awn(P 0.05);but it insignificantly affected leaf width,stem node diameter and spike area(P 0.05).CO2 concentration elevation increased the photosynthetic area per stem of "Xiaoyan 6" and "Xiaoyan 22" by 8.1%~15.1% and 2.8%~13.2%,respectively,with the biggest variable amplitude under the nitrogen application level of 0.30 g(N).kg 1(soil).Under three nitrogen levels,CO 2 enrichment increased spike grain number and the ratio of grain number-leaf area in varying degrees.The grain number-leaf area ratio of two varieties increased most obviously under 0.30 g(N).kg 1(soil) and 0.15 g(N).kg 1(soil),with 44.2% and 41.4% increments compared with the ambient CO 2 concentration.Moreover,high CO 2 concentration reduced spike grain weight and the ratio of grain weight-leaf area under no nitrogen application,but raised them by 43.6% and 20.7% averagely under nitrogen application.The awn area was only 3% of the total photosynthetic area,greatly smaller than those of other resources organs.It suggested that CO 2 enrichment enlarge the photosynthetic area of wheat mainly through elongating leaves and stem.It improved the relationship between sources and sink to increase sink number and mater translocation captivity per unit leaf area simultaneously.Nitrogen addition would promote the response of wheat source and sink growth to CO 2 enrichment.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2013年第9期1049-1056,共8页
Chinese Journal of Eco-Agriculture
基金
中央高校基本科研业务费专项(QN2009083)资助
关键词
冬小麦
CO2浓度
施氮
光合面积
粒叶比
库源关系
Winter wheat
CO2 concentration
Nitrogen addition
Photosynthetic area
Grain-leaf ratio
Sources-sink relationship