不同氮素浓度下CO2浓度、温度对蒙古栎（Quercus mongolica）幼苗叶绿素含量的影响

叶片中叶绿素含量在光合作用中的光吸收、传递和转换过程中起到重要作用。为了预测未来大气CO2浓度升高并伴随温度上升的情况下,植物在不同的氮素营养水平下光合能力的变化,做了在3种氮素水平下（15mmol·L^-1 N,7.5mmol·L^-1 N和不施氮）CO₂倍增和温度升高4℃对蒙古栎一年生幼苗叶片中叶绿素含量的影响的实验。结果表明：氮素水平对叶绿素含量影响显著,在CO₂倍增(700μmol·mol^-1)、高温(+4℃)和正常温度、大气CO₂浓度条件下,高氮素水平下的叶绿素含量明显高于正常氮素水平和不施氮;CO₂浓度和温度对叶绿素含量的影响受到氮素的制约：在高氮的条件下CO₂浓度倍增促进叶绿素a、b的合成,而且对叶绿素b合成的促进尤为显著;而温度升高4℃能够促进叶绿素a的合成,但是对叶绿素b含量的影响不显著。在正常氮素条件下叶绿素a、叶绿素b及总量各个处理间的差异均不显著;在不施氮的条件下,CO₂倍增和升高适当的温度在一定的程度上可以促进叶绿素a的合成,不能同时保证叶绿素b的合成。CO₂浓度升高明显导致蒙古栎幼苗对氮素水平的需求也增加,高温条件下的蒙古栎幼苗也在一定程度上增加了对氮素的需求。     

浓度倍增对城市油松抗氧化酶活性的影响

利用OTC（开顶箱）法模拟未来CO₂浓度,于CO₂倍增浓度（700 μmol·mol^-1）和正常空气CO₂浓度(≈350 μmol·mol^-1）条件下,测定了沈阳市区油松（Pinus tabulaeformis）针叶超氧自由基（O^·₂）产生速率、过氧化氢（H₂O₂）含量、超氧化物歧化酶（SOD）与抗坏血酸-谷胱甘肽循环（ASA-GSH cycle）主要酶活性动态变化,探讨高浓度CO₂对油松抗氧化酶活性的影响。结果表明：在短期(60 d)内CO₂浓度倍增使油松超氧自由基（O₂^·）产生速率与过氧化氢（H₂O₂）含量减少,而SOD、抗坏血酸过氧化物酶（APX）、单脱氢抗坏血酸还原酶（MDAR）、脱氢抗坏血酸还原酶（DHAR）、谷胱甘肽还原酶（GR）活性升高;植株抗氧化能力增强,对活性氧清除能力提高;但长期（70 d以上）CO₂浓度倍增处理则可能使试验结果发生逆转。     

CO2浓度升高对红松和长白松土壤呼吸作用的影响

以开顶箱法研究了CO₂浓度升高对红松和长白松土壤呼吸作用的影响.结果表明,500 μmol CO₂·mol^-1使红松和长白松土壤呼吸速率明显降低,土壤表面CO₂浓度升高导致CO₂扩散受阻可能是土壤呼吸受到抑制的主要原因.500 μmol CO₂·mol^-1下两树种土壤表面CO₂浓度明显高于对照箱和裸地条件下的CO₂浓度,增加幅度在40～150 μmol·mol^-1之间;对照箱内长白松土壤表面CO₂浓度略高于裸地,差异不显著,红松差异显著500 μmol CO₂·mol^-1下的长白松土壤全氮及总有机碳含量略高于对照组,差异不显著,红松裸地的碳氮含量明显低于500 μmol CO₂·mol^-1 及对照箱内土壤碳氮含量;500 μmol CO₂·mol^-1 及开顶箱的微环境对地下3 cm处土壤温度没有明显影响.     

CO2浓度倍增、高氮沉降和高降雨对南亚热带人工模拟森林生态系统土壤呼吸的影响

 土壤呼吸响应全球气候变化对全球C循环具有重要作用。应用大型开顶箱(Open-top chamber, OTC)人工控制手段, 研究了大气CO₂浓度倍增、高氮沉降和高降雨处理对南亚热带人工森林生态系统土壤呼吸的影响。结果表明: 对照箱、CO₂浓度倍增处理以及高氮沉降处理下土壤呼吸速率都具有明显的季节变化, 雨季(4~9月)的土壤呼吸速率显著高于旱季(10月至次年3月) (p<0.001); 但高降雨处理下无明显的季节差异(p>0.05)。CO₂浓度倍增能显著提高土壤呼吸速率(p<0.05), 其他处理则变化不大。大气CO₂浓度倍增、高氮沉降、高降雨处理和对照箱的土壤呼吸年通量分别为4 241.7、3 400.8、3 432.0和3 308.4 g CO₂·m^–2·a^–1。但在不同季节, 各种处理对土壤呼吸的影响是不同的。在雨季, 大气CO₂浓度倍增和高氮沉降的土壤呼吸速率显著提高(p<0.05), 其他处理无显著变化; 而在旱季, 高降雨的土壤呼吸速率显著高于对照箱(p<0.05), 氮沉降处理则抑制土壤呼吸作用(p<0.05)。各处理的土壤呼吸速率与地下5 cm土壤温度之间具有显著的指数关系(p<0.001); 当土壤湿度低于15%时, 各处理的土壤呼吸速率与地下5 cm土壤湿度具有显著的线性关系(p<0.001)。     

高浓度二氧化碳对百合生长和两种化感物质的影响

在大棚栽培条件下,研究不同CO₂浓度（600、800、1 000 μmol·mol^-1）对亚洲型黄花多头切花百合的影响.结果表明,CO₂浓度为600 μmol·mol^-1时,切花百合维持较高的Pn,在CO₂浓度为600～1 000 μmol·mol^-1时并持续45 d,百合并未出现明显的光合作用下调,这与新生子球对高CO₂浓度下的百合光合适应性具有一定调节能力有关.CO₂浓度为600 μmol·mol^-1时,能提高百合切花0.57个茎高等级,对显色花蕾增长有正效应.不同CO₂浓度对百合叶片中的多酚类和类黄酮含量影响不同,CO₂浓度为600和800 μmol·mol^-1时,能明显提高多酚类和类黄酮含量,植株也未出现叶枯病病株,这与适宜的高CO₂浓度对Pn及碳水化合物的形成和转化以及化感物质与提高百合自身抗病性有关.在试验浓度范围内,CO₂浓度为600 μmol·mol^-1时最有利于百合叶片多酚类和类黄酮含量的提高.     

高浓度二氧化碳处理对红松幼苗土壤水解酶活性的影响

研究了700和500 μmol·mol^-1高浓度CO₂处理的红松幼苗0～10 cm土层土壤蛋白酶、脲酶、淀粉酶、转化酶和磷酸酶活性的变化.结果表明,土壤蛋白酶(除7月)、脲酶、淀粉酶(除7月)和磷酸酶(除9月)活性在高浓度CO₂条件下极显著增加,而转化酶(除9月)活性却极显著降低.不同高浓度CO₂对酶活性的影响程度不同,500 μmol·mol^-1浓度CO₂处理对蛋白酶和磷酸酶活性的影响较700 μmol·mol^-1处理明显,而700 μmol·mol^-1浓度CO₂处理对脲酶、淀粉酶和转化酶活性的影响较500 μmol·mol^-1显著.     

遮光处理对西葫芦幼苗形态特征及光合生理特性的影响

研究了不同遮光处理对西葫芦幼苗形态及光合生理特性的影响.结果表明,在60%透光率条件下,西葫芦幼苗具有较高的相对生长率、净光合速率、气孔导度、蒸腾速率、单叶水分利用效率、饱和蒸汽压、表观量子效率和叶绿素含量,而胞间CO₂浓度较低;西葫芦幼苗具有较高的光饱和点(1 125 μmol·m^-2·s^-1)、较低的光补偿点(15.2 μmol·m^-2·s^-1).弱光下西葫芦幼苗较耐低浓度CO₂,而强光下的幼苗较耐高浓度CO₂.60%透光率下西葫芦幼苗叶片丙二醛和脯氨酸含量最低,而过氧化物酶和过氧化氢酶活性则最高.     

不同氮素水平下二氧化碳加富对草莓叶片光抑制的影响

用便携式调制叶绿素荧光仪和光合仪研究了强光下不同供氮水平（12、4和0.4 mmol·L^-1）和不同CO₂浓度下（700和390 μl·L^-1）丰香草莓叶片的荧光参数及净光合速率的变化.结果表明,CO₂和氮素对草莓叶片光抑制有明显的互作效应.在富CO₂下,12 mmol·L^-1供氮水平的草莓叶片净光合速率升高了62.7%,4和0.4 mmol·L^-1供氮水平则分别降低了7.4%和21.3%;12 mmol·L^-1供氮水平的F_m和F_v/F_m在强光胁迫时降辐减小,暗恢复时F_m和F_v/F_m恢复程度提高,而4和0.4 mmol·L^-1供氮水平却相反.表明氮素供应不足时草莓叶片在富CO₂环境下光合作用出现适应性下调,光抑制增强.     

CO2浓度倍增减轻UV-B辐射对大棚番茄的抑制作用研究

在CO2浓度倍增(700 μmol·mol-1)条件下,以5个不同剂量的UV-B辐射对大棚番茄的光合作用及SOD、POD、CAT酶活性的影响进行了研究.结果表明CO2倍增能够明显提高番茄叶绿素含量、净光合速率和抗氧化酶活性.在CO2倍增条件下,低剂量UV-B辐射(<1.163 kJ·m-2·d-1)可以刺激番茄叶片叶绿素含量升高,抗氧化酶活性升高,与CO2的正效应有叠加现象,但对光合作用的影响不大;高剂量的UV-B(>1.163 kJ·m-2·d-1)辐射使植株的叶绿素含量、净光合速率和抗氧化酶活性降低,对植物产生胁迫作用,CO2倍增与UV-B辐射复合处理可以减弱和部分抵消这种抑制作用.     

红豆草与土壤氮含量对大气二氧化碳浓度升高的响应

在封闭的植物培养箱中,通过盆栽实验,研究了红豆草和土壤氮含量对CO₂浓度增加的响应.结果表明,与正常CO₂浓度(355～370 μmol·mol^-1)相比,CO₂浓度升高(700 μmol·mol^-1),植物生物量增加25.1%(P＜0.01),但植物体氮浓度降低25.3%(P＜0.001),植物全氮没有显著的变化.经3个月盆栽实验后,与原始土壤相比,两种CO₂浓度处理土壤全N、NO₃^--N和NH₄⁺-N都有所降低,而土壤微生物氮则显著增加,这可能与植物生长有关.不同CO₂浓度处理土壤NH₄⁺-N浓度基本一致,但在高CO₂浓度下,土壤NO₃^--N浓度显著降低,而微生物生物氮显著增加.对整个土壤-植物系统而言,盆栽实验后,整个系统全氮有少量增加,但变化不显著,特别是在高CO₂浓度条件下,土壤-植物系统全氮最大,这可能与培养材料红豆草为豆科植物,而且在高CO₂浓度下生物量增加,导致氮的固定量增加有关.     

Combined effects of enhanced ultraviolet-B radiation and doubled CO2 concentration on growth, fruit quality and yield of tomato in winter plastic greenhouse

Five different doses of ultraviolet-B (UV-B)radiation were supplied to tomato (Lycopersicon esculeutum.in the winter plastic greenhouse.The influences on the seedling growth,fruit quality and yield of tomato were investigated.Results showed that the seedling growth,and the contents of UV absorbing compounds,soluble sugar,organic acid,vitamin C and lycopene of tomato fruits,and yield of tomato increased under doubled CO2 concentration.Under the doubled CO2 concentration the effects of lost doses of UV-B radiation could further promote the effects of doubled CO:concentration.However,there is no significant increase in yield of tomato.The best dose of UV-B radiation is about 1.163 kJ.m-2.When the dose of UV-B radiation is more than it,the effects of UV-B will be reduced.     

CO2浓度倍增和UV-B辐射增强对冬季大棚番茄生长、果实品质和产量的影响

在CO₂浓度倍增(700μmol·mol^-1)条件下,对补充5个不同低剂量的UV-B辐射对大棚番茄幼苗的株高、茎粗、干重、鲜重,果实的紫外吸收物、可溶性糖、有机酸、Vc、番茄红素等含量,以及果实产量的影响进行了研究。结果表明,CO₂倍增能够明显促进番茄幼苗的生长,提高了番茄果实的紫外吸收物、可溶性糖、有机酸、Vc、番茄红素等含量以及果实的产量。在CO₂倍增条件下,补充低剂量UV-B辐射可以进一步促进番茄幼苗的生长,提高番茄果实的紫外吸收物、可溶性糖、有机酸、Vc、番茄红素等含量,说明在CO₂倍增的条件下低剂量UV-B辐射对番茄的生长有促进效应,但对果实的产量影响不大。当UV-B的辐射剂量为1.163kJ·m^-2时,这种促进效应最明显,超过这一剂量时,UV-B辐射对番茄的促进效应开始减弱。     

Combined effects of enhanced ultraviolet-B radiation and doubled CO2 concentration on growth, fruit quality and yield of tomato in winter plastic greenhouse

Five different doses of ultraviolet-B (UV-B) radiation were supplied to tomato (Lycopersicon esculeutum. Mill) with the doubled CO₂ concentration (700 μmol · mol⁻¹) in the winter plastic greenhouse. The influences on the seedling growth, fruit quality and yield of tomato were investigated. Results showed that the seedling growth, and the contents of UV absorbing compounds, soluble sugar, organic acid, vitamin C and lycopene of tomato fruits, and yield of tomato increased under doubled CO₂ concentration. Under the doubled CO₂ concentration the effects of lost doses of UV-B radiation could further promote the effects of doubled CO₂ concentration. However, there is no significant increase in yield of tomato. The best dose of UV-B radiation is about 1.163 kJ·m⁻². When the dose of UV-B radiation is more than it, the effects of UV-B will be reduced. __________ Translated from Journal of Wuhan Botanical Research, 2006, 24(1): 49–53 [译自: 武汉植物学研究]     

UV－B辐射增强对长白山五种藓类植物生长的影响

对生长在中国长白山的5种藓类植物——垂枝藓、拟垂枝藓、塔藓、星塔藓和高山金发藓分别以辐射强度为0.2(自然光照,对照)、3.0(紫外线中等辐射强度)和6.0kJ.m-2.d-1(高剂量辐射强度)的UV-B照射40d后,测定其株高、生物量及叶绿素含量.结果表明:中等和高强度的UV-B辐射使拟垂枝藓和塔藓的株高、生物量和叶绿素含量分别下降了32.3%、62.4%、81.3%和21.4%、59.4%、62.8%,其相对生长速率均为负值;高剂量UV-B辐射处理下垂枝藓的生物量稍有上升,而高山金发藓地下部分的生物量增加1倍,但叶绿素含量变化不明显.高山金发藓和垂枝藓抵抗UV-B辐射的能力较强,拟垂枝藓和塔藓对UV-B辐射较敏感.     

Enhanced UV-B radiation has little effect on growth, δ13C values and pigments of pot-grown rice (Oryza sativa) in the field

Predicted increase in ultraviolet-B (UV-B: 280–320 mn) radiation may have adverse impacts on growth and yield of rice ( Oryza sativa L.), as has been found in studies hitherto. However, most of the studies were conducted in growth chambers or greenhouses where the plants are generally more sensitive to UV-B than in the field, presumably because of the distorted balance between UV-B and ultraviolet-A as well as PAR. This study was conducted to address the effects of enhanced UV-B on growth and yield of rice under a realistic spectral balance in the field. Three cultivars, "Koshihikari",'IR 45'and'IR 74'were pot-grown and irradiated with enhanced UV-B for most of the growing season in the field at Tsukuba, Japan (36°01'N, 140°07'E). The UV-B enhancement simulated ca 38% depletion of stratospheric ozone at Tsukuba. The results showed no UV-B effects on plant height, numbers of tillers and panicles, dry weight of the plant parts or the grain yield for any of the 3 cultivars. Natural abundance of ¹³C in the flag leaves was not altered by the UV-B enhancement either. While UV-absorbing compounds showed no response to the UV-B enhancement, chlorophyll contents decreased with enhanced UV-B. However, the decrease of chlorophyll was limited to an early growth stage with no effect later. We thus found no extraordinary impact of the nearly doubled UV-B radiation on rice in the field, and it would appear that a reliable prediction of the effects of UV-B will require experiments carried out over a number of years under various climatic and solar UV-B regimes.     

UV-B辐射对报春花的生理生化效应

通过室内模拟试验,研究不同强度的UV-B辐射(10μW/cm2和20μW/cm2)对报春花生理代谢的影响,结果表明:(1)增强UV-B辐射下,报春花叶片叶绿素含量降低,且随UV-B辐射时间的延长,降低程度加大;(2)随UV-B辐射强度的增加,叶片质膜透性增加;(3)叶片类黄酮含量随着UV-B辐射强度的增加而增加,在辐射至40 d时,叶片类黄酮含量达到最大值;(4)增强UV-B辐射下,报春花花瓣中花青素含量增加.     

Senescence and hyperspectral reflectance of cotton leaves exposed to ultraviolet-B radiation and carbon dioxide

The objectives of this study were to determine the effects of UV-B radiation and atmospheric carbon dioxide concentrations ([CO(2)]) on leaf senescence of cotton by measuring leaf photosynthesis and chlorophyll content and to identify changes in leaf hyperspectral reflectance occurring due to senescence and UV-B radiation. Plants were grown in controlled-environment growth chambers at two [CO(2)] (360 and 720 micro mol mol(-1)) and three levels of UV-B radiation (0, 7.7 and 15.1 kJ m(-2) day(-1)). Photosynthesis, chlorophyll, carotenoids and phenolic compounds along with leaf hyperspectral reflectance were measured on three leaves aged 12, 21 and 30 days in each of the treatments. No interaction was detected between [CO(2)] and UV-B for any of the measured parameters. Significant interactions were observed between UV-B and leaf age for photosynthesis and stomatal conductance. Elevated [CO(2)] enhanced leaf photosynthesis by 32%. On exposure to 0, 7.7 and 15.1 kJ of UV-B, the photosynthetic rates of 30-day-old leaves compared with 12-day-old leaves were reduced by 52, 76 and 86%, respectively. Chlorophyll pigments were not affected by leaf age at UV-B radiation of 0 and 7.7 kJ, but UV-B of 15.1 kJ reduced the chlorophylls by 20, 60 and 80% in 12, 21 and 30-day-old leaves, respectively. The hyperspectral reflectance between 726 and 1142 nm showed interaction for UV-B radiation and leaf age. In cotton, leaf photosynthesis can be used as an indicator of leaf senescence, as it is more sensitive than photosynthetic pigments on exposure to UV-B radiation. This study revealed that, cotton leaves senesced early on exposure to UV-B radiation as indicated by leaf photosynthesis, and leaf hyperspectral reflectance can be used to detect changes caused by UV-B and leaf ageing.     

UV-B辐射对8个大豆品种种子萌发率和 幼苗生长的影响

在生长房5种(暗处、可见光、低、中、高强度紫外线-B)处理下,研究了8个大豆品种的种子萌发率和萌发后幼苗的生长状况。结果表明,暗处种子萌发率高于自然光和UV-B辐射的种子。UV-B辐射增强对大豆种子的萌发率没有显著影响,仅使部分品种的最大萌发率降低和导致部分品种达到最大萌发率的时间延长。幼苗的生长对增强的UV-B辐射非常敏感。使大部分品种的胚根变短增粗,这可能是植物激素作用的结果。大豆的叶绿素a、叶绿素b和总叶绿素含量明显受到UV-B辐射的抑制。UV-B作用能促进类黄酮在幼苗中的积累,紫外吸收色素的增设有利于提高对UV-B的抵抗力。UV-B辐射的这种效应及大豆品种间的差异在自然情况下会产生深远的生物学和生态学意义     

UV-B Radiation Suppresses the Growth and Antioxidant Systems of Two Marine Microalgae, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium (Ehrenb.) W. Sm

This study investigated whether increased solar UV-B radiation (280-315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium (Ehrenb.) W. Sm, were exposed to a range of UV-B radiation and both showed reductions in their growth rates, and the chlorophyll a (Chl a) and carotenoid (Car) contents when UV-B radiation dose increased. Superoxide anion radical (O2)production and the concentration of hydrogen peroxide (H2O2) and malodiadehyde (MDA) also increased with the increasing of UV-B radiation. Antioxidant systems, non-enzymic components (Car and glutathione content) and enzymic components (superoxide dismutase (SOD) and catalase (CAT) activity), decreased as a result of enhanced UV-B radiation. When the exogenous glutathione (GSH) was added, the effects of UVB radiation on the growth of the two species were alleviated. These results suggest that enhanced UV-B radiation suppressed the antioxidant systems and caused some active oxygen species to accumulate, which in turns retarded the development of the marine microalgae.     

云杉种子萌发和幼苗生长对气候变暖与UV B辐射增强的响应

采用开顶式有机玻璃罩(OTCs)及紫外灯分别模拟气候变暖和UV-B增强,对位于气候变暖和UV-B增强突出的青藏高原东缘的高山峡谷地云杉种子萌发、幼苗生长和光合色素含量的变化进行测定分析,探讨云杉对气候变暖和UV-B增强的响应机理。结果显示:(1)UV-B辐射增强对云杉种子萌发无显著影响,但显著抑制萌发幼苗的生长、降低其针叶叶绿素含量,并造成幼苗大量死亡(P<0.05)。(2)气候变暖使云杉种子提前萌发,并提高了发芽势、发芽率和发芽指数,促进幼苗生长和叶绿素的积累,显著降低幼苗死亡率(P<0.05)。(3)气候变暖缓解了UV-B增强对云杉萌发幼苗生长和叶绿素含量的抑制作用,并降低了UV-B胁迫下幼苗的死亡率。研究表明,在未来气候变暖和UV-B辐射增强同时存在时,气候变暖能够在一定程度上缓解UV-B增强对云杉林早期更新带来的抑制作用。