摘要
采用20W和40W的UV-B灯辐射增强处理,测定分析了UV-B辐射增强对麻花艽(Gentiana straminea Maxim)叶片净光合速率及相关生理参数的影响.结果显示:2008年8月3日,研究区大气温度从09:00开始上升,到14:00达到最高点,叶温和大气饱和水气压变化与气温变化趋势相似;光合有效辐射强度从07:00开始上升,至13:00达到最高,之后下降;麻花艽叶片净光合作用速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(E)和水分利用效率在对照下最高,在40WUV-B辐射下最低;Pn在08:00—10:00最高,Gs在07:00—08:00最高,Ci在日出及日落时最高,E在09:00—13:00及14:00—18:00最高,水分利用效率在日出后最高;Pn与Gs,叶片温度,大气温度,光合有效辐射和大气饱和水气压亏缺呈正相关,与Ci呈负相关,与光合有效辐射强度的相关系数较高.Pn在光合有效辐射强度为0～800μmol/(m2·s)时随光合有效辐射强度增加而增加,在2200～3000μmol/(m2·s)时变化不大;Gs和E随光合有效辐射强度的增加而增加;Ci在光合有效辐射强度为0～800μmol/(m2·s)时,随光合有效辐射强度的增加而呈下降趋势;水分利用效率在光合有效辐射强度为0～800μmol/(m2·s)时随光合有效辐射强度的增加而呈增加的趋势,在800～3000μmol/(m2·s)时呈下降趋势.说明UV-B辐射增强将使高寒草甸植物叶片Pn,Gs,Ci,E和水分利用效率降低.
The effects of enhanced UV-B radiation on the laminae net photosynthetic rate and related physiological parameters of strawyellow gentian（Gentiana straminea Maxim） were determined and analyzed by using 20 W and 40 W UV-B lamps to increase the UVB radiation.The results showed that air temperature in the studied area began to rise from 09：00 am and peaked at 14：00.The variation trend of leaf temperature was similar with that of the atmospheric saturated vapor pressure and air temperature on August 3rd,2008.The photosynthetic active radiation（PAR） intensity began increasing at 07：00 am,peaked at 13：00,and then decreased.The laminae net photosynthetic rate（Pn）,stomata conductance（Gs）,intercellular CO2 concentration（Ci）,transpiration rate（E） and water use efficiency（WUE） of straw-yellow gentian were the highest under the control treatment,and lowest under 40 W UV-B lamp treatment.Pn was the highest from 08：00-10：00;Gs was the highest from 07：00-08：00;Ci was the highest at time of sunrise or sunset;E was the highest at 09：00-13：00 or 14：00-18：00;and,WUE was the highest after sunrise.Pn was positively related with Gs,leaf temperature,atmosphere temperature,PAR or atmospheric saturated vapor pressure deficit,and negatively related with Ci.The correlation coefficient between Pn and PAR was higher.Additionally,the results showed that Pn increased with increasing PAR when the PAR ranged from 0-800 μmol /（m^2·s）,but it varied little when the PAR ranged from 2200-3000 μmol /（m^2·s）.Gs and E increased with increasing PAR.Ci decreased with increasing PAR when the PAR ranged from 0-800 μmol /（m^2·s）.WUE increased with increasing PAR when the PAR ranged from 0-800 μmol/（m^2·s）,but decreased when PAR ranged from 800-3000 μmol/（m^2·s）.The results indicated that enhanced UV-B radiation would result in decreases of Pn,Gs,Ci,E or WUE of alpine meadows leaves.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2010年第11期1395-1404,共10页
Research of Environmental Sciences
基金
中央级公益性科研院所基本科研业务专项(2007KYYW05)
关键词
UV-B辐射
高寒草甸
光合作用
麻花艽
青藏高原
UV-B radiation
alpine meadows
photosynthesis
straw-yellow gentian
Qinghai-Tibet plateau
