温度对铁皮石斛生长及生理特性的影响

通过不同温度下的控制实验,研究了铁皮石斛光合作用与生长对温度的响应,以期为铁皮石斛的栽培提供理论依据。温度对铁皮石斛的光合速率（Pn）有明显影响,30℃处理的植株具有最高的饱和光合速率（Pmax）,其较高的光合速率与RuBP电子传递速率与羧化速率间相对平衡有关。温度对铁皮石斛茎的生长及多糖含量有明显影响,20℃处理的石斛多糖含量显著性的高于其他两个处理,而茎长、茎节数、茎鲜重等则是在30℃下最高。结果表明,30℃的温度对铁皮石斛的光合作用较为适宜,但在20℃条件下植株具有更高的多糖含量。     

铁皮石斛叶片光合作用的碳代谢途径

 利用LI-6400光合测定系统测定了不同天气条件下铁皮石斛（Dendrobium officinale）叶片24h CO2吸收的动态以及CO2吸收对光强和温度的响应。晴天的白天和夜间铁皮石斛都能吸收CO2,中午CO2吸收速率为负值, CO2的交换方式具景天酸代谢途径(CAM)的特点。阴雨天,只有白天吸收CO2,夜间表现为暗呼吸,光合作用碳代谢的途径为C3途径。在多云的天气条件下,白天吸收CO2,并持续至日落后。夜间21∶00仍有CO2吸收,23∶00以后至次日凌晨处于暗呼吸状态。在500 μmol·m-2·s-1光照件下,20℃出现最大CO2吸收值。在夜间,25℃时CO2的吸收速率最高。有光和无光条件下,低温或高温引起CO2吸收速率下降均为非气孔因素所致。晴天上午,铁皮石斛叶片的表观量子产额为0.035,光合补偿点为2.9μmol·m-2·s-1,饱和光强为500μmol·m-2·s-1,强光下出现光抑制现象。叶片受到强光预先照射后,即使光照减弱光抑制效应仍保持一段时间,致使光合补偿点升高,表观量子产额下降,相同光强下的CO2吸收效率降低。结果表明：铁皮石斛为兼性CAM植物,随着环境条件的变化,其光合作用在景天酸代谢途径(CAM)与C3途径间变化。     

温度变化对烟草光合作用光响应特征的影响

通过Li-6400光合测定系统控温,研究了大田条件下,烟草脚叶采烤期腰叶在17、20、25、30和35℃下的光合作用光响应特征。结果表明:随温度升高,净光合速率(Pn)、最大净光合速率(Pnmax)、初始斜率(α)和气孔导度(Gs)先上升后下降,在20℃下达最大值,35℃下净光合速率受强光的抑制作用明显;光补偿点(LCP)和暗呼吸速率(Rd)随温度升高而上升,但35℃下二者较30℃时有所下降;光饱和点(LSP)随温度升高而呈下降-上升-下降的变化,30℃和17℃时LSP较高;蒸腾速率(Tr)随温度上升而增强,水分利用效率(WUE)则随温度升高而下降,但20℃时水分利用效率在强光下明显较其他温度下的高。结果说明,20℃最适合烟草光合作用,此温度下气孔的水、气调节能力最强,温度高于30℃则对烟草光合作用不利。     

不同光照强度和温度对金钗石斛生长的影响

为了系统地研究不同光照强度下温度对金钗石斛(Dendrobium nobile)生长的影响,在金钗石斛分蘖期,于80μmol·m-2·s-1、160μmol·m-2·s-1、320μmol·m-2·s-1、640μmol·m-2·s-1的不同光强下,各设置5个温度(15℃、20℃、25℃、30℃、35℃)梯度对石斛进行处理。结果表明：石斛的生长与代谢随温度由低到高,表现出弱—强—弱的变化规律;80μmol·m-2·S-1光强下,石斛生长以25～30℃较为适宜;160μmol·m-2·s-1光强下则以20～25℃为适宜温度范围;320μmol·m-2·s-1与640μmol·m-2·s-1的中、强光照下,25℃处理石斛的生长优势尤为明显;不同光强下,石斛鲜重的增长大多以25℃处理更快,繁殖力则以20℃与25℃处理较高,各光强下的MDA含量随温度升高而先降后升,且均以25℃最低;可溶性蛋白质、可溶性总糖及叶绿素含量则表现出随温度由低到高而先增后减的趋势,其含量最高点均出现在25℃左右;净光合速率和叶绿素含量随光强和温度的变化趋势基本一致;各种光强下的暗呼吸速率均随温度升高而增大。因此,在不同的光照条件下,石斛生长的适宜温度均在25℃左右。光温处理引起石斛生理生化过程明显的相应变化表现出：高温和弱光照条件有利于石斛的株高增长,但不利于产量和质量提高;石斛的生长与MDA含量呈显著负相关(r80＝-0.9082、r160＝-0.9816、r320＝-0.8075、r640＝-0.8586),与可溶性糖含量呈一定正相关(r80＝0.7673、r160＝0.8892、r320＝0.8179、r640＝0.9278),并且石斛的生长与可溶性蛋白质含量、叶绿素含量、光合速率之间的变化趋势基本一致。     

温度对七叶一枝花光合特性及皂苷含量的影响

该研究以珍稀濒危药用植物七叶一枝花(Paris polyphylla)为材料,利用人工气候箱设置3个温度条件,即低温(10℃/16℃)、适温(18℃/24℃)、高温(26℃/32℃),采用盆栽法分析了不同温度条件对七叶一枝花光合特性和主要有效成分皂苷含量的影响。结果表明:(1)适温条件下,七叶一枝花叶绿素含量、最大光合速率、光饱和点、表观量子效率均高于低温和高温处理,而光补偿点、暗呼吸速率则低于两者。(2)适温条件下,七叶一枝花根茎体内皂苷含量最大,达到了4.33%,低温和高温处理下皂苷含量分别只有适温的42.26%和33.49%,氨基酸含量同样表现为适温处理下最大。(3)七叶一枝花有效成分含量与叶片叶绿素含量、光合速率呈显著正相关,而与呼吸速率呈显著负相关,说明温度直接影响植株的光合作用、呼吸作用,进而影响有效成分的积累。温度对七叶一枝花光合特性及有效成分的积累影响显著,22℃左右的平均温度(18℃/24℃)是七叶一枝花栽培的适宜温度,此温度有利于其生长及有效成分的积累,该研究结果为七叶一枝花人工栽培中温度的科学管理提供了依据。     

Intraspecific variation in temperature dependence of gas exchange characteristics among Plantago asiatica ecotypes from different temperature regimes

There are large inter- and intraspecific differences in the temperature dependence of photosynthesis, but the physiological cause of the variation is poorly understood. Here, the temperature dependence of photosynthesis was examined in three ecotypes of Plantago asiatica transplanted from different latitudes, where the mean annual temperature varies between 7.5 and 16.8 degrees C. Plants were raised at 15 or 30 degrees C, and the CO(2) response of photosynthetic rates was determined at various temperatures. When plants were grown at 30 degrees C, no difference was found in the temperature dependence of photosynthesis among ecotypes. When plants were grown at 15 degrees C, ecotypes from a higher latitude maintained a relatively higher photosynthetic rate at low measurement temperatures. This difference was caused by a difference in the balance between the capacities of two processes, ribulose-1,5-bisphosphate regeneration (J(max)) and carboxylation (V(cmax)), which altered the limiting step of photosynthesis at low temperatures. The organization of photosynthetic proteins also varied among ecotypes. The ecotype from the highest latitude increased the J(max) : V(cmax) ratio with decreasing growth temperature, while that from the lowest latitude did not. It is concluded that nitrogen partitioning in the photosynthetic apparatus and its response to growth temperature were different among ecotypes, which caused an intraspecific variation in temperature dependence of photosynthesis.     

低温胁迫下丛枝菌根真菌对玉米光合特性的影响

利用盆栽试验,在15 ℃和5 ℃低温胁迫下研究了丛枝菌根（AM）真菌对玉米生长、叶绿素含量、叶绿素荧光和光合作用的影响.结果表明：低温胁迫抑制了AM真菌的侵染;接种AM真菌的玉米地上部和地下部干物质量、相对叶绿素含量高于不接种植株.与非菌根玉米相比,菌根玉米具有较高的最大荧光（F_m）、可变荧光（F_v）、最大光化学效率（F_v/F_m）和潜在光化学效率（F_v/F_o）及较低的初始荧光（F_o）,并且在5 ℃处理中差异显著.接种AM真菌使玉米叶片的净光合速率（P_n）和蒸腾速率（T_r）显著增强;低温胁迫下,菌根植株的气孔导度（G_s）显著高于非菌根植株;而胞间CO₂浓度（C_i）显著低于非菌根植株.表明AM真菌可通过提高叶绿素含量及改善叶片叶绿素荧光和光合作用来减轻低温胁迫对玉米植株造成的伤害,提高玉米耐受低温的能力,进而提高玉米的生物量,促进玉米生长.     

海拔对高山栎光合气体交换和叶性状的影响

理解影响植物分布的式样及过程是生态学研究的中心内容之一,但对许多物种而言,限制其分布的原因还不清楚。为了认识高山栎分布与生理生态特性的关系,我们在不同海拔的4个观测点研究了帽斗栎的光合气体交换、叶氮含量、叶绿素含量和比叶重。由于高的水气压亏缺和气温,帽斗栎的光合作用和蒸腾作用在午间表现出明显的降低现象。帽斗栎的饱和光合速率、水分利用效率、最大羧化速率、最大电子传递速率和氮利用效率在海拔中部比低海拔或高海拔处的为高。不同海拔的叶氮含量在5月份有差异,8月份则没有明显不同。叶片厚度随海拔增加,但叶绿素含量及光合最适温度随海拔升高而降低。帽斗栎光合作用的海拔变化与叶片的生化效率和氮含量有关,而与比叶重无关。研究结果说明,温度的海拔变化对高山栎的光合作用和叶性状有明显影响,最适宜帽斗栎光合碳获取及生长的海拔范围是3180～3610m。     

Photosynthetic response of P-deficient Gracilaria tenuistipitata under two different phosphate treatments

Phosphorus-deficient Gracilaria tenuistipitata Zhang et Xia was cultured for 15 days at two different inorganic phosphate (P_i) concentrations: 3 μM (low P_i treatmenl) or 30 μM phosphate (high P_i treatment). The amount of ribulose-l,5-bisphosphate carboxy-lase/oxygenase (Rubisco), phycobiliproteins, Chl a and total soluble proteins were higher in the high P_i than in the low P_i treatment. The total N content of the low P_i plants was lower than in plants grown at high P_i concentrations whereas the amount of total C was highest in low P_i plants. The increase of Rubisco content in the high P_i treatment (3-fold) was parallel to the enhancement of the maximum photosynthetic rate which increased 5-fold. This correspondence was also found in the low P_i treatment in which Rubisco content and maximum photosynthesis did not change significantly from the initial values. The photosynthetic efficiency was also higher at high than at low P_i. The high P_i plants also showed higher dark respiration and growth rates. The data presented here suggest that marine macroalgae submitted to P_i deficiency exhibit a decrease in growth caused not only by P_i implication on energy transfer in photosynthesis and respiration, but also by the diminution of the amount of photosynthetic pigments and Rubisco.     

霍山石斛的光合特性研究

本文研究了霍山3种石斛的光合特性、气孔日变化与生态因子的相关性,研究结果表明,石斛光合作用的净光合速率、光饱和点、光补偿点均低,要求低光强和散射光.相对湿度是影响光合作用和气孔开闭的主要因子.相对湿度降低,净光合速率也降低.白天气温在20℃以下,相对湿度在80%以上时,气孔开闭随光强变化呈单峰曲线;气温在20℃以上,相对湿度达90%以上时,气孔开张度与光强呈强正相关,相对湿度降低到80%以下,气孔开张度与光强无相关性.气孔日变化出现双峰曲线.叶绿素b含量略高,在短波光430nm处吸收峰较高,表现了阴性植物的光合特性.     

亚高温下不同空气湿度对番茄光合作用和物质积累的影响

为了研究亚高温下不同空气湿度对番茄植株光合作用及物质积累的影响,本试验利用人工气候室,在11:00—15:00平均温度为33℃的亚高温条件下,设置3个空气相对湿度处理,分别为70%～80%(高湿)、50%～60%(中湿)和不加湿的30%～40%(低湿)。结果表明:在处理25d时,高湿处理番茄叶片叶绿素含量、净光合速率显著高于低湿处理,而低湿处理果实空洞率比高湿处理高18.4%(P<0.05);在33℃亚高温条件下,70%～80%的相对湿度有利于光合作用的增强和果实品质的提高。     

Physiological ecology of Juniperus virginiana in oldfields

Juniperus virginiana plants grow faster than other associated tree species in abandoned fields. During the summer the needles of the species do not light saturate even at 1,750 E m^-2 s^-1, reach optimum photosynthesis at 20°C, and maintain maximum photosynthesis at-8 to-12 bar twig water potential. In the field, the plants experience pronounced daily changes in water potential. The magnitude of the changes becomes more pronounced later in the summer. Leaves of the mature plants have highest rate of photosynthesis, young trees intermediate, and seedlings lowest. In winter there is a slight shift in optimum temperature for photosynthesis and the plants photosynthesize at 0°C. The rates of photosynthesis are lower in winter than in summer. On sunny days with calm winds, mature individuals and seedlings maintain significantly higher temperatures than air temperature while intermediate plants do not. The latter exhibit a lower photosynthetic rate than both mature plants and seedlings. The trends of photosynthesis, in the 3 size classes, both in winter and summer, correspond to the chlorophyll content of their leaves. It is concluded that J. virginiana grows well in open field habitats because it is a sun-adapted, drought resistant species with a long growing season which includes winter. The species is excluded from mature forests because it is shade-intolerant.     

不同光照强度对西洋参光合特性,营养成分和产量的影响

在２１．６％自然光强下生长的西洋参叶片,光合作用的光饱和点和光补偿点皆比１１％自然光强下的高．在恒定条件下,光合作用最适温度为２８℃．２１．６％自然光强下的光合产物,较多地分配到根部,１１％自然光强下则分配到果实中的高．光合速率在一定范围内随透光强度的增加而提高,以透光３０％的叶片为最高．其日变化呈双峰曲线．叶绿素含量在一定范围内随光强的增加而降低,叶绿素ｂ含量的变化亦为同样趋势．叶片结构以弱光和强光相比,在上表皮角质层花纹、下表皮气孔数、叶肉细胞形状、叶绿体数及其基粒片层结构都有明显差别．参的产量随光强的增加而显著增加,但以透光３０％时增长幅度最大,４０％时增长变小．根中总皂苷和氨基酸含量在一定范围内随光强而增加,至透光４０％时又下降．     

Effects of Growth Temperature on the Responses of Ribulose-1,5-Biphosphate Carboxylase,Electron Transport Components,and Sucrose Synthesis Enzymes to Leaf Nitrogen in Rice,and Their Relationships to Photosynthesis

Effects of growth temperature on the photosynthetic gas-exchange rates and their underlying biochemical properties were examined in young, fully expanded leaves of rice (Oryza sativa L.). The plants were grown hydroponically under day/night temperature regimes of 18/15[deg]C, 23/18[deg]C, and 30/23[deg]C and all photosynthetic measurements were made at a leaf temperature of 25[deg]C and an irradiance of 1800 [mu]mol quanta m-2 s-1. Growth temperature affected the photosynthetic CO2 response curve. The relative ratio of the initial slope to the CO2-saturated photosynthesis increased with rising growth temperature. This was caused mainly by an increase in CO2-limited photosynthesis for a given leaf nitrogen content with rising growth temperature. However, there was no difference in ribulose-1,5-bisphosphate carboxylase (Rubisco) content at any given leaf nitrogen content among temperature treatments. In addition, the activation state and catalytic turnover rate of Rubisco were not affected by growth temperature. The increase in CO2-limited photosynthesis with rising growth temperature was the result of an increase in the CO2 transfer conductance between the intercellular airspaces and the carboxylation sites. The amounts of total chlorophyll and light-harvesting chlorophyll a/b protein II increased for the same leaf nitrogen content with rising growth temperature, but the amounts of cytochrome f and coupling factor 1 and the activities of cytosolic fructose-1,6-bisphosphatase and sucrose-phosphate synthase were the same between plants grown at 23/18[deg]C and those grown at 30/23[deg]C. Similarly, CO2-saturated photosynthesis was not different for the same leaf nitrogen content between these treatments. For the 18/15[deg]C-grown plants, a slight decrease in the amounts of cytochrome f and coupling factor 1 and an increase in the activities of cytosolic fructose-1,6-bisphosphatase and sucrose-phosphate synthase were found, but these were not reflected in CO2-saturated photosynthesis.     

Tufted Hairgrass (Deschampsia caespitosa) Exhibits a Lower Photosynthetic Plasticity than Antarctic Hairgrass (D. Antarctica)

The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins (a temperate zone species, Deschampsia caespitosa (L.) Beauv. and an Antarctic species, D. antarctica) and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem Ⅱ (PSII) quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4℃ but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica,irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8℃ were similar in both species. The photosynthetic water-use efficiency (photosynthesis-to-transpiration ratio, P/E) emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the P/E values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.     

基质温度对三角梅插穗生根及其叶片光合作用的影响

探讨了智能调控下18、20、25、30、33℃的5个基质温度处理对三角梅叶片光合作用及插穗生根的影响.结果表明:随着基质温度上升,三角梅插穗叶片净光合速率增加,18、20℃处理的净光合速率较低,两处理间未见显著性差异,但均显著地低于处理间未见明显差异的25、30、33℃处理.随着基质温度上升,叶片蒸腾速率、气孔导度及胞...     

西北干旱区不同海拔高度地区气温变化对春小麦生长的影响

基于1981—2006年西北干旱区高海拔地（民乐站）和低海拔地（张掖站）农业气象观测站的观测资料,对民乐站和张掖站的气温变化及其对春小麦生长发育和产量的影响进行了研究.结果表明：研究期间,民乐站、张掖站的气温均呈增加趋势,且高海拔地区的增温幅度大于低海拔地区;民乐站春小麦对气温变暖的响〖JP2〗应表现为生育期缩短、产量增加,张掖站春小麦对气温变暖的响应表现为生育期缩短、产量下降;春小麦生育期内日均气温每升高1 ℃,民乐站和张掖站春小麦生育期分别缩短8.3 d和3.8 d.民乐站春小麦生育期内最高气温低于30.4 ℃时,春小麦生育期和产量均小幅增加,当超过30.4 ℃时,春小麦生育期缩短、产量下降.     

海拔对高山栎光合气体交换和叶性状的影响

理解影响植物分布的式样及过程是生态学研究的中心内容之一,但对许多物种而言,限制其分布的原因还不清楚。为了认识高山栎分布与生理生态特性的关系,我们在不同海拔的4个观测点研究了帽斗栎的光合气体交换、叶氮含量、叶绿素含量和比叶重。由于高的水气压亏缺和气温,帽斗栎的光合作用和蒸腾作用在午间表现出明显的降低现象。帽斗栎的饱和光合速率、水分利用效率、最大羧化速率、最大电子传递速率和氮利用效率在海拔中部比低海拔或高海拔处的为高。不同海拔的叶氮含量在5月份有差异,8月份则没有明显不同。叶片厚度随海拔增加,但叶绿素含量及光合最适温度随海拔升高而降低。帽斗栎光合作用的海拔变化与叶片的生化效率和氮含量有关,而与比叶重无关。研究结果说明,温度的海拔变化对高山栎的光合作用和叶性状有明显影响,最适宜帽斗栎光合碳获取及生长的海拔范围是3180~3610m。     

温度对谷皮菱形藻生长及其理化成分的影响

考察了不同温度对谷皮菱形藻生长及其理化成分的影响。结果表明:温度在10℃或30℃条件下不利于细胞生长,同时也不利于胞内理化成分的积累。在20℃条件下细胞密度、叶绿素含量、胞内蛋白、胞外多糖及胞内多糖达到最大值。谷皮菱形藻的最适生长温度为20℃,10℃可以作为种质保存的温度。     

Temperature response of photosynthesis in C3, C4, and CAM plants: temperature acclimation and temperature adaptation

Most plants show considerable capacity to adjust their photosynthetic characteristics to their growth temperatures (temperature acclimation). The most typical case is a shift in the optimum temperature for photosynthesis, which can maximize the photosynthetic rate at the growth temperature. These plastic adjustments can allow plants to photosynthesize more efficiently at their new growth temperatures. In this review article, we summarize the basic differences in photosynthetic reactions in C₃, C₄, and CAM plants. We review the current understanding of the temperature responses of C₃, C₄, and CAM photosynthesis, and then discuss the underlying physiological and biochemical mechanisms for temperature acclimation of photosynthesis in each photosynthetic type. Finally, we use the published data to evaluate the extent of photosynthetic temperature acclimation in higher plants, and analyze which plant groups (i.e., photosynthetic types and functional types) have a greater inherent ability for photosynthetic acclimation to temperature than others, since there have been reported interspecific variations in this ability. We found that the inherent ability for temperature acclimation of photosynthesis was different: (1) among C₃, C₄, and CAM species; and (2) among functional types within C₃ plants. C₃ plants generally had a greater ability for temperature acclimation of photosynthesis across a broad temperature range, CAM plants acclimated day and night photosynthetic process differentially to temperature, and C₄ plants was adapted to warm environments. Moreover, within C₃ species, evergreen woody plants and perennial herbaceous plants showed greater temperature homeostasis of photosynthesis (i.e., the photosynthetic rate at high-growth temperature divided by that at low-growth temperature was close to 1.0) than deciduous woody plants and annual herbaceous plants, indicating that photosynthetic acclimation would be particularly important in perennial, long-lived species that would experience a rise in growing season temperatures over their lifespan. Interestingly, across growth temperatures, the extent of temperature homeostasis of photosynthesis was maintained irrespective of the extent of the change in the optimum temperature for photosynthesis (T _opt), indicating that some plants achieve greater photosynthesis at the growth temperature by shifting T _opt, whereas others can also achieve greater photosynthesis at the growth temperature by changing the shape of the photosynthesis–temperature curve without shifting T _opt. It is considered that these differences in the inherent stability of temperature acclimation of photosynthesis would be reflected by differences in the limiting steps of photosynthetic rate.