摘要
采用盆栽试验方法,以NaCl为盐分模拟不同盐度环境,研究了施氮(N)对盐环境下生长的甜菜(Beta vulgaris)功能叶光系统Ⅱ(PSⅡ)荧光特性的影响及光合色素含量的变化。结果表明:在轻度、中度及重度盐环境下,施N均能增大PSⅡ最大光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、PSⅡ实际光量子产量(Y(Ⅱ))、非调节性能量耗散的量子产量(Y(NO))、相对电子传递速率(ETR)及光化学猝灭系数(qP),且在适宜的施N范围内(0–1.2g·kg–1)上述参数随施N量的增加而增大。各叶绿素荧光参数光响应的结果表明,随着光强的增加,各处理下调节性能量耗散的量子产量(Y(NPQ))、ETR及非光化学猝灭系数(NPQ)呈上升趋势,相反,Y(Ⅱ)、Y(NO)及qP则呈下降趋势,在有效的光强范围内(0–1000μmol·m–2·s–1)施N提高了甜菜功能叶PSⅡ反应中心的开放程度,并且在高光强下调节PSⅡ耗散掉过剩的光能以避免对其反应中心造成伤害。各盐度环境下施N也显著增加了甜菜功能叶叶绿素与类胡萝卜素含量,增大了叶绿素a/叶绿素b值,且叶绿素与类胡萝卜素含量随施N水平的增加而增加。说明盐环境下施N能够增强甜菜功能叶PSⅡ的活性,提高PSⅡ光能利用率,从而增强其对盐渍环境的适应性。
Aims Our objective was to determine the effects of nitrogen regulation on photosystem Ⅱ （PSⅡ） chlorophyll fluorescence of functional leaves in sugar beet （Beta vulgaris） under salt environment. Methods Using potted sugar beet plants, different salt environments were produced with NaCl; nitrogen was produced with NH4NO3. Important findings Maximal PSⅡ quantum yield （Fv/Fm）, and latent PSⅡ quantum yield （Fv/Fo）, effective PSⅡ quantum yield （Y（Ⅱ））, quantum yield of non-regulated energy dissipation （Y（NO））, electron transport rate （ETR） and coefficient of photochemical quenching （qP） were increased by nitrogen application under mild, moderate and high salt environments, and these parameters increased with increased nitrogen application. The results of rapid light-response curves of chlorophyll fluorescence parameters showed that quantum yield of regulated energy dis-sipation （Y（NPQ））, ETR and coefficient of nonphotochemical quenching （NPQ） increased with the increase of light intensity under every treatment. By contrast, Y（Ⅱ）, Y（NO） and qP decreased with increased light intensity. Openness of PSⅡ reaction centers of functional leaves in sugar beet were also improved in range of effective in-tensity （0–1000 μmol·m–2·s–1） by nitrogen application, and PSⅡ was adjusted to dissipate excess photon energy to protect the PSⅡ reaction centers. Application of nitrogen could also increase the content of chlorophyll, carotenoid and ratio of chlorophyll a to chlorophyll b, and the content of chlorophyll and carotenoid were increased with the increase of nitrogen application under every salt environment. These results indicated that PSⅡ activity and light-use efficiency could be improved by nitrogen application, and then the adaptability of sugar beet to salt en-vironment was strengthened.
出处
《植物生态学报》
CAS
CSCD
北大核心
2013年第2期122-131,共10页
Chinese Journal of Plant Ecology
基金
农业部公益性行业科研专项(2009-03001-4)
"十二五"农村领域国家科技计划课题(2012AA101404-6)
关键词
甜菜
叶绿素荧光
氮素
光合色素
盐度
Beta vulgaris
chlorophyll fluorescence
nitrogen
photosynthetic pigments
salinity
