光照强度和氮水平对白三叶幼苗生长与光合生理特性的影响  

Effects of light intensity and nitrogen application on the growth and photosynthetic characteristics of Trifolium repens L.

作　　者：安慧[1,2] 上官周平[2] 

机构地区：[1]宁夏大学西北退化生态系统恢复与重建省部共建教育部重点实验室,西部生态与生物资源开发联合研究中心,宁夏银川750021 [2]西北农林科技大学水土保持研究所,陕西,杨陵712100

出　　处：《生态学报》2009年第11期6017-6024,共8页Acta Ecologica Sinica

基　　金：国家科技部重大基础研究前期研究专项(973预研)(2008CB426304);国家教育部长江学者和创新团队发展计划资助项目(IRT0749);宁夏大学自然科学基金资助项目(ZR200838)

摘　　要：采用植物生长箱溶液培养方式,对白三叶幼苗进行了不同光强(2个水平)和氮浓度(5个水平)处理,探讨其生长、生物量和光合生理特征对生境变化的响应。结果表明:两种光强下白三叶幼苗茎和叶生物量随氮素浓度呈先升高后降低,而根系生物量和根冠比则随氮素浓度增高而降低。光照强度降低使白三叶幼苗根、茎、叶和整株生物量分别降低67.8%、29.9%、42.5%和45.2%;低光处理使幼苗的根冠比显著下降,而比叶面积(SLA)明显提高。幼苗根系体积随氮素浓度增高而降低,高生长光强根系体积显著高于低生长光强下的白三叶。幼苗根系表面积、根系长度和根系直径随氮素浓度增加呈先增加后降低趋势,两种不同生长光强下幼苗根系长度和根系直径差异显著,而根系表面积差异不明显。白三叶叶片光合速率(Pn)随氮素浓度增加呈先增加后降低趋势,高生长光强白三叶Pn显著高于低生长光强下的白三叶。两种生长光强间叶片气孔导度(Gs),胞间CO2浓度(Ci)和蒸腾速率(Tr)无显著差异,但氮素浓度对叶片Gs、Ci和Tr均有显著影响。光、氮及其交互作用对白三叶幼苗生长发育产生了显著影响,光照不足和氮缺乏都将导致白三叶幼苗生长减弱,但幼苗对这些不利环境具有较强的调节和适应能力。The responses of Trifolium repens L. seedlings in growth, biomass and photosynthetic characteristics to 2 light intensity levels and 5 nitrogen application rate levels were hydroponically studied in growth chamber. The results showed that the stem and leaf biomass of Trifolium repens L. seedlings increased as the nitrogen concentrations increased from 5 to 15 mmol·L^-1 and then decreased with the nitrogen concentrations moved from 20 to 25 mmol·L^-1, but the root biomass and root/shoot ratio of Trifolium repens L. seedlings decreased with the increasing nitrogen concentration. The biomass of roots, stems, leaves and whole plant under low light decreased by 67.8% , 29.9% , 42.5% and 45.2% , respectively, and the root/shoot ratios decreased, but the specific leaf areas （ SLA ） was opposite. The root volumes of Trifolium repens L. seedlings decreased with the increasing nitrogen concentrations, when the root volume of Trifoliura repens L. seedlings at the higher light intensity were higher than those at the lower light intensity. The root surface areas, root diameters and root lengths of Trifoliurn repens L. seedlings increased as the nitrogen concentrations from 5 to 15 mmol·L^-1 and then decreased with the nitrogen concentrations moved from 20 to 25mmol·L^-1. The effects of light intensity on root length and root diameter of Trifolium repens L. seedlings significantly differed, but the root surface areas did not significantly differed. The photosynthetic rates （Pn） of Trifolium repens L. seedlings at the higher light intensity were higher than those at the lower light intensity, and the Pn increased as the nitrogen concentrations increased from 5 to 15mmol·L^-1 and then decreased as the nitrogen concentrations moved from 20 to 25 mmol·L^-1. The effects of light intensity on stomatal conductance （ G5 ）, intercellular CO2 concentration （ Ci ） and transpiration rate （ Tr ） did not significantly differed, but the effects of nitrogen concentration on G5, Ci and T were significant. The effect o

关 键 词：白三叶 光合生理特征 生长特性 光强 氮浓度 

分 类 号：S541.2[农业科学—作物学]