不同氮素条件下米槁光响应曲线拟合模型的比较分析

分析了施氮量对米槁幼苗光响应曲线的影响。采用砂培法,设置4种不同的氮素浓度,利用直角双曲线模型、非直角双曲线模型、直角双曲线修正模型等6种模型对米槁叶片进行光响应曲线拟合。此外,也对相关光合参数的响应过程做了探讨。结果表明,在不同氮素处理下,修正模型拟合的各项光合参数结果与实测值比较接近。其中,在N3处理下,米槁幼苗LSP(1 722.041 μmol·m^-2·s^-1)、P_nmax(8.295 μmol·m^-2·s^-1)、AQE(0.027 μmol·m^-2·s^-1)均大于其他处理,LCP(13.769 μmol·m^-2·s^-1)小于其他处理;且随着施氮量的增加,米槁叶片叶绿素含量、净光合速率P_n、气孔导度G_s、蒸腾速率T_r呈增大的趋势,胞间CO₂浓度C_i呈下降的趋势。因此,增施氮量能够显著改变米槁对光的适应幅度,提高叶片光能利用率。     

3个苹果品种气体交换特性及其对环境因子的响应

利用Li-6400光合作用系统对3个苹果品种（富士、早富一号、新富一号）的净光合速率（P_n）、气孔导度(G_s)、胞间CO₂的浓度（C_i）、蒸腾速率（T_r）和水分利用效率（WUE）以及光响应曲线等生理指标进行测定、对比分析。结果表明:1）3个苹果品种均是高光合、高蒸腾、高水分利用效率的品种,富士光饱和点(LSP) 和光补偿点(LCP)分别为1 542.8 μmol·m^-2·s^-1、30.4 μmol·m^-2·s^-1,早富一号LSP和LCP分别为1 618.8 μmol·m^-2·s^-1、26.6 μmol·m^-2·s^-1,新富一号LSP和LCP分别为1 189.4 μmol·m^-2·s^-1、41.8 μmol·m^-2·s^-1。2）富士的P_n、T_r日变化呈“单峰”曲线;早富一号、新富一号的P_n、T_r日变化均呈“双峰”曲线分布,并且存在光合“午休”现象。3）影响富士P_n、T_r日变化的主要内外界环境因子及作用大小的顺序分别依次为:PPFD>G_s、RH>T_air >G_s;影响早富一号P_n、T_r日变化的主要内外界环境因子以及作用大小的顺序分别依次为:PPFD >G_s>RH、RH>T_air>G_s>PPFD;影响新富一号Pn、T_r日变化的主要内外界环境因子以及作用大小的顺序分别依次为:PPFD >G_s > RH>T_air、RH>T_air >G_s> PPFD。     

不同覆盖栽培年限雷竹林光合生理研究

为揭示覆盖栽培竹林生理生态变化机制,给竹林生态修复技术研究提供依据,分别对覆盖0、3、6、9 a和12 a雷竹林光合性状和光响应特征等进行研究。结果表明:竹林净光合速率（P_n）随覆盖年限增长,逐渐减小,在覆盖6 a时显著减小;气孔导度（G_s）随覆盖年限增长,逐渐减小,覆盖9 a时显著减小;覆盖6 a后竹林胞间CO₂浓度（C_i）均高于覆盖0、3 a竹林;蒸腾速率（T_r）总体随竹林覆盖年限增长,逐渐减小,在覆盖3 a时即显著减小;竹林水分利用效率（WUE）以覆盖3 a竹林最高,覆盖12 a竹林最低;P_n与G_s呈极显著正相关,与T_r呈显著正相关,与C_i呈负相关,但相关不显著;竹林光响应过程中,光合有效辐射（PAR）达20 μmol·m^-2·s^-1后,覆盖3 a竹林P_n均高于其他竹林,PAR升高至400 μmol·m^-2·s^-1后,各竹林P_n以覆盖12 a竹林最低;覆盖3 a竹林潜在最大净光合速率（P_max）最大,覆盖12 a竹林最小;覆盖0 a竹林光补偿点（LCP）最低,覆盖6 a后竹林LCP均在10.000 μmol·m^-2·s^-1以上;覆盖6 a竹林光饱和点（LSP）最高,达737.703 μmol·m^-2·s^-1。结论认为:覆盖对竹林光合作用起到制约作用,覆盖时间越长,竹林越难以形成可持续生产力;竹林覆盖至第6年,光合生理发生显著减弱,竹林种群受覆盖胁迫越来越严重,此时,需要及时养竹以更新竹林和采取有效的竹林恢复措施,同时,要重点开展竹林土壤生态修复技术研究,以促进实现竹林可持续经营。     

不同整形方式对酿酒葡萄赤霞珠果实品质的影响

为促进酿酒葡萄赤霞珠的优质栽培,以20年生赤霞珠酿酒葡萄为试材,采用直立独龙蔓和厂形两种整形方式,通过物候期的调查和果实品质的测定,研究不同整形方式对酿酒葡萄赤霞珠果实品质的影响。结果表明,厂形的萌芽期和着色期均较直立独龙蔓提前了5 d,且厂形的净光合速率(25.82μmol·m^-2·s^-1)、气孔导度(371.44μmol·m^-2·s^-1)、胞间CO₂浓度(475.23μmol·mol^-1)、蒸腾速率(8.08μmol·m^-2·s^-1)均高于直立独龙蔓(23.24μmol·m^-2·s^-1、254.72μmol·m^-2·s^-1、401.15μmol·mol^-1、5.13μmol·m^-2·s^-1),但两种整形方式下叶片的蒸腾速率存在显著差异,其他光合指标差异均不显...     

不同种源地北美鹅掌楸光合特性研究

以3个种源地北美鹅掌楸无性系为试验材料,利用LI-6400XT便携式光合测定系统,研究了净光合速率日变化及对有效光辐射和CO₂的响应等光合特性。结果表明,宾夕法尼亚种源和俄亥俄种源北美鹅掌楸的P_n日变化曲线呈双峰型,具有明显的午休现象,峰值出现在10:00和14:00,纽约种源北美鹅掌楸不具有明显的午休现象。光响应曲线和CO₂响应曲线数据分析表明,纽约种源北美鹅掌楸光饱和点（1 180.4 μmol·m^-2·s^-1）和光补偿点（10.27 μmol·m^-2·s^-1）均高于另外2个种源。这种趋势也同样适用于CO₂饱和点（1 595.0 μmol·m^-2·s^-1）和CO₂补偿点（107.5 μmol·m^-2·s^-1）。在北方低光照环境下,纽约种源较高的光补偿点和CO₂补偿点,不利于有机物的积累,宾夕法尼亚种源对光照和CO₂要求较低,更适合北方环境。     

不同栽植年限小叶杨与胡杨杂交种（小×胡杨）光合响应特性比较

了解不同光强对小×胡杨气体交换参数的影响,可为进一步评价小×胡杨新品种适应性提供基础数据,为乌兰布和沙漠东北部防护林体系的更新及造林树种选择提供一定的理论依据。利用Li-6400xt便携式光合仪测定了不同光强下小×胡杨的光合生理参数,利用非直角双曲线模型,拟合植物叶片净光合速率（P_n）与光合有效辐射（PAR）的关系,计算光饱和速率（A_max）,光饱和点（LSP）,光补偿点（LCP）,表观量子效率（AQY）,暗呼吸效率（RD）等光合生理参数。结果表明,在光合有效辐射（PAR）0～1 500 μmol·m^-2·s^-1范围内,不同栽植年限小×胡杨净光合速率均随着光合有效辐射（PAR）的增强而增加,当光合有效辐射（PAR）为1 500 μmol·m^-2·s^-1时,曲线处于缓慢上升趋势,小×胡杨还没有达到光饱和点。不同光合有效辐射,净光合速率值均表现为3年>2年>1年生,1年、2年、3年生小×胡杨之间的净光合速率差异显著（P<0.05）。3年生小×胡杨的光饱和速率（A_max）、光饱和点（LSP）、光补偿点（LCP）、表观量子效率（AQY）最高。1年生小×胡杨的暗呼吸速率最大,3年小×胡杨的暗呼吸速率最小。在光合有效辐射（PAR）0～1 500 μmol·m^-2·s^-1,不同栽植年限小×胡杨气孔导度（G_s）均随光合有效辐射（PAR）的增加而增加,而胞间CO₂ 浓度（C_i）均呈逐步下降的趋势;随着有效光辐射的逐步增强,不同栽植年限小×胡杨蒸腾速率逐渐增加,变化趋势都较缓慢平稳,蒸腾速率对光合有效辐射（PAR）的变化并不敏感。当光合有效辐射<600 μmol·m^-2·s^-1,1年、2年、3年生小×胡杨水分利用效率增加迅速,当光合有效辐射>600 μmol·m^-2·s^-1,随着光强的增强,3年生小×胡杨水分利用效率继续缓慢上升,但1年、2年生的小×胡杨水分利用效率趋于平缓甚至下降。综合分析,1年、2年、3年生小×胡杨具有高光合,高水分利用效率和相对较低的蒸腾速率的特点,表现出了对当地生态气候的良好适应性。     

Regulation of Foliar Application DCPTA on Growth and Development of Maize Seedling Leaves in Heilongjiang Province

DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.     

采煤沉陷区模拟侵蚀破坏对小叶锦鸡儿光合生理特性的影响

为明确半干旱矿区植物生长及生理特性对侵蚀破坏的响应机制,以小叶锦鸡儿为对象,分析其枝叶生长、光合生理指标及水分利用效率在根系不同程度断裂损伤后的变化特征。结果表明,根系损伤对小叶锦鸡儿生长产生明显抑制作用,随损伤程度增大,抑制作用越明显,重度损伤后株高、冠幅、枝条长度和直径增长率相比对照分别降低了62.5%、61.1%、73.3%和74.4%;根系损伤对小叶锦鸡儿的各项光合指标均存在明显的抑制作用,同样具有根系损伤程度越大,叶片光合指标越低的变化趋势,以净光合速率为例,表现为对照(22.40 μmol·m^-2·s^-1)>轻度损伤(20.44 μmol·m^-2·s^-1)>中度损伤(17.33 μmol·m^-2·s^-1)>重度损伤(15.20 μmol·m^-2·s^-1),而且根系损伤对光合指标的抑制作用在损伤形成后将长期存在,持续弱化叶片的光反应能力;根系损伤会改变小叶锦鸡儿叶片的水分利用效率,损伤程度越大,水分利用效率越高,表现为重度损伤(4.30 μmol·mmol^-1)>中度损伤(3.97 μmol·mmol^-1)>轻度损伤(3.61 μmol·mmol^-1)>对照(3.52 μmol·mmol^-1)。综合分析说明,在侵蚀破坏造成根系损伤后,小叶锦鸡儿会通过减缓生长和光合速率,降低水分需求,实现维持自身生存、生长和再生产的生存策略。     

12个网纹草品种的光合光响应曲线(简报)

测定了12个网纹草主要栽培品种的光合光响应曲线,通过曲线拟合和计算得到光饱和点、光补偿点等光合作用参数。结果表明:各品种最大光合速率均比较低,最高的是‘Red Star’,仅为4.74μmol·m^-2·s^-1;所有品种的光饱和点均在240～521μmol·m^-2·s^-1,因此在栽培时应控制光照条件,PAR小于520μmol·m^-2·s^-1为宜,否则易发生日灼;所有测试品种的光补偿点均小于7μmol·m^-2·s^-1,说明这些网纹草品种均可适应室内极弱光照条件。     

基于叶绿素荧光的荆条灌丛对栓皮栎幼苗庇荫效应研究

利用叶绿素荧光这一光合作用的敏感指针,对比研究了荆条灌丛下和对照裸地的栓皮栎（Quercus variabilis）幼苗荧光参数在不同天气类型下的反映,同时也测定了栓皮栎幼苗的光曲线,得到了光饱和点和半饱和光强。结果表明,灌丛下与裸地的叶片Fv/Fm和Y(Ⅱ)、qL和qN、Y(NPQ)和Y(NO)等在晴天、多云、阴天下均有不同的反映,均表现出荆条灌丛的庇荫效应。结论:1)栓皮栎幼苗的光饱和点为1 942 μmol·m^-2·s^-1,半饱和光强为235 μmol·m^-2·s^-1,显现出栓皮栎并不具有对强光的特殊耐受力;2)晴天中午时段裸地叶片有明显的光抑制,但这种光抑制处于可逆的范围;3)Fv/Fm等叶绿素荧光参数反映出灌丛下栓皮栎幼苗叶片的光合活性高、光保护能力强,光合状况优于对照,荆条灌丛对栓皮栎幼苗生长具有明显的保护效应。     

Effect of Nitric Oxide on Alleviating Cadmium Toxicity in Rice (Oryza sativa L.)

Nitric oxide （NO） is a gaseous signaling molecule in plants that plays a key role in mediating a wide range of physiological processes and responses to biotic and abiotic stresses. The present study was conducted to investigate the effects of the exogenous application of sodium nitroprusside （SNP）, an NO donor, on cadmium （Cd）-induced oxidative stress and Cd uptake in rice plants. Rice plants were exposed to Cd stress (0.2 mmol L^-1 CdCl₂) and different concentrations of SNP (0.05, 0.1, 0.2, and 0.4 mmol L^-1). A SNP concentration of 0.1 mmol L^-1 （SNP10） significantly reduced the Cd-induced decrease in shoot and root dry weights and leaf chlorophyll concentrations. The addition of NO also reduced the malondialdehyde （MDA）, hydrogen peroxide （H₂O₂） and ascorbic acid （ASA） concentrations. However, the reduction in glutathione （GSH） concentration was inhibited by NO treatment. Moreover, NO prevented the Cd-induced increase in antioxidative enzyme activity. The amount of Cd accumulation in rice plants was also influenced by the addition of NO. The NO supplied by the SNP enhanced the Cd tolerance of the rice by increasing the Cd uptake by the roots and decreasing the Cd accumulation by the shoots. However, the application of potassium ferrocyanide （Cd+Fe） or sodium nitrate and nitrite （Cd+N） （without NO release）, did not exhibit the effects of the SNP. Furthermore, the effects of the SNP were reversed by the addition of hemoglobin （an NO scavenger）. Our results suggested that exogenous NO was involved in the resistance of rice to Cd-toxicity.     

Optimization of Quantitative Real-time PCR System on Amplification of Beta-glucosidase Gene Os1bglu4

[Objective] This study aimed to establish a quantitative real-time PCR(qRT-PCR) system for detecting the expression of rice beta-glucosidase gene Os1bglu4. [Method] The PCR was conducted with SYBR Green I method, using the primers of reference gene actin or ubiquitin. [Result] Actin was more suitable to be the reference gene than ubiquitin. More accurate results were obtained when the 100 ng cDNA template was added at a large volume and a lower concentration.The primer concentration in the range from 0.2 to 0.8 μmol/L we set had no significant influence on the results, so, 0.4 μmol/L was selected as the optimal primer concentration in this study. The amplification efficiency was greatly reduced when the annealing temperature was set at 64 ℃, therefore, annealing temperature was set at 60 ℃. Compared with the reaction system of 25 μl, the fluorescence intensity was significantly lower but the CT value did not change greatly in 10 μl system.So, the 10 μl reaction system was selected, which significantly reduces the research costs for the detection of a large amount of samples in future study.     

Exogenous Application of Abscisic Acid or Gibberellin Acid Has Different Effects on Starch Granule Size Distribution in Grains of Wheat

Granule size distribution of wheat starch is an important characteristic that can affect its chemical composition and the functionality of wheat products. Two high-yield winter wheat cultivars were used to evaluate the effects of the application of exogenous ABA or GA during the reproductive phase of the initial grain filling on starch granule size distribution and starch components in grains at maturity. The results indicated that a bimodal curve was found in the volume and surface area distribution of grain starch granules, and a unimodal curve was observed for the number distribution under all treatments. The exogenous ABA resulted in a significant increase in the proportions （both by volume and by surface area） of B-type （<9.9 μm in diameter） starch granules, with a reduction in those of A-type （>9.9 μm） starch granules, while, the exogenous GA₃ led to converse effects on size distribution of those starch granules. The exogenous ABA also increased starch, amylose and amylopectin contents at maturity but significantly reduced the ratio of amylose to amylopectin. Application of GA₃ significantly reduced starch content, amylopectin content but increased the ratio of amylose to amylopectin. The ratio of amylose to amylopectin showed a significant and negative relationship with the volume proportion of granules <9.9 μm, but was positively related to the volume proportion of granules 22.8-42.8 μm.     

Comparison of phenolic profiles and antioxidant activities in skins and pulps of eleven grape cultivars(Vitis vinifera L.)

Eleven grape cultivars were analysed to explore the variety differences of fresh grape phenolic profiles. The results showed that free phenolics were predominant in grape skins and pulps, and showed the higher antioxidant activities than bound. In 11 cultivars, Muscat Kyoho extracts had the highest total phenolic content in skins(10.525 mg GAE g~(–1) FW) and pulps(1.134 mg GAE g~(–1) FW), and exhibited the highest DPPH radical scavening capacity(EC_(50)=11.7 μg mL~(–1)) and oxygen radical absorbance capacity(ORAC) value(190.57 μmol TE g~(–1) FW) of free phenolic in skin. In addition, the most abundant phenolics in grape skins were found to be flavonoids such as kaempferol in Kyoho skin(541.2 μg g~(–1) FW), rutin, catechin and epicatechin in Muscat Kyoho skin(262.3, 86.3 and 70.0 μg g~(–1) FW, respectively). Furthermore, the principal component analysis showed a strong difference of phenolic profiles with the cultivars, existing forms and distributions. Pearson correlation coefficient analysis showed a significant linear correlation between total phenolic content and antioxidant activity(P0.05). Therefore, both skins and pulps were rich sources of bioactive phenolic compounds, and Muscat Kyoho was the ideal source among all samples.     

阿克苏5种果树滞尘量对其水分利用效率的影响

选择新疆阿克苏市柯柯牙典型的5种果树:红枣（Ziziphus jujuba）、核桃（Juglans regia）、苹果（Malus pumila）、葡萄（Vitis vinifera）和香梨（Pyrus sinkiangensis）,并对树种叶面滞尘量及其对水分利用效率的影响进行研究。结果表明,5种果树滞尘能力为葡萄5.37 mg/cm²>香梨4.55 mg/cm²>红枣3.88 mg/cm²>核桃3.03 mg/cm²>苹果0.92 mg/cm²。水分利用效率为葡萄（2.646 μmol·mmol^-1）＞香梨（1.810 μmol·mmol^-1）＞核桃（1.698 μmol·mmol^-1）＞红枣（1.359 μmol·mmol^-1）＞苹果（1.043 μmol·mmol^-1）。通过分别比较5种果树滞尘量与水分利用效率之间的相关性得出,5种果树的滞尘量与净光合速率、蒸腾速率、水分利用效率之间并无显著相关关系。表明果树在长期适应极端环境的过程中,形成了自身的调节机制,滞尘量对果树的水分利用效率的影响不大。     

The Effect of Vineyard Cover Crop on Main Monomeric Phenols of Grape Berry and Wine in Vitis viniferal L. cv. Cabernet Sauvignon

This study was conducted to determine the effect of cover crop inter-row in vineyard on main mono-phenol content of grape berry and wine. Three such cover crops, two perennial legumes （white clover and alfalfa） and a perennial gramineous grass （tall fescue） were sown in vineyard. The main phenolic compounds of mature grape berry and wines vinified under the same conditions were extracted with ethyl acetate and diethyl ether and analyzed by high- performance liquid chromatography （HPLC） by comparing to soil tillage. A total of ten phenolic compounds were identified and quantified in the different grape berry and wines, including nonflavonoids （hydroxybenzoic and hydroxycinnamic acids） and flavonoids （flavanols and flavonols）. The concentration of flavonoid compounds （409.43 to 538.63 mg kg^-1 and 56.16 to 81.30 mg L^-1） was higher than nonflavonoids （76.91 to 98.85 mg kg^-1 and 30.65 to 41.22 mg L^-1） for Cabernet Sauvignon grape and wine under different treatments, respectively. In the flavonoid phenolics, Catechin was the most abundant in the different grapes and wines, accounting for 74.94 to 79.70% and 48.60 to 50.62% of total nonanthocyanin phenolics quantified, respectively. Compared to soil tillage, the sward treatments showed a higher content of main mono-phenol and total nonanthocyanin phenolics in grapes and wines. There were significant differences between two cover crop treatments （tall fescue and white clover） and soil tillage for the content of benzoic acid, salicylic acid, caffeic acid, catechin, and total phenolics in the grape berry （P 〈 0.05 or P〈0.01）. The wine from tall fescue cover crop had the highest gallic acid, caffeic acid and catechin. Cover crop system increased the total nonanthocyanin phenolics of grapes and wines in order of the four treatments： tall fescue, white clover, alfalfa, and soil tillage （control）. Cover crop in vineyard increased total phenols of grape berry and wine, and thus improved the quality of wine evidently.     

Effects of CuSO4 and Uniconazole on Mature Embryo Culture in Japonica Rice

In order to establish the system of high frequency plant regeneration for japonica rice mature embryos, the effects of different concentrations of CuSO4 and uniconazole on in vitro culture of mature embryos were studied using three rice cultivars of Kongyu 131, Longjing 24, and Dongnong 425 as test materials. The results showed that callus induction and differentiation of japonica rice mature embryos were apparently improved on the medium with 10-15 μmol·L-1 CuSO4 and 0.50-1.00 mg·L-1 uniconazole. Induction and differentiation rates of different genotype rice mature embryos displayed different sensitivities to CuSO4 and uniconazole. For the callus induction frequency of three varieties, the optimal concentration of CuSO4 was 15.0 mol·L-1. When the concentration of CuSO4 was 15 μmol·L-1, the plantlet differentiation rates of Kongyu 131 and Dongnong 425 got to the highest, while the concentration of CuSO4 was 10 μmol·L-1 for Longjing 24. For the callus induction and plantlet differentiation rates of Kongyu 131 and Dongnong 425, the ideal concentration of uniconazole was 0.50 mg·L-1 and for Longjing 24 was 1.00 mg·L-1.     

The Determination of Canthaxanthin in Feed Ingredients by High Performance Liquid Chromatography

A series of studies were conducted to establish a methodology for the accurate and efficient determination of canthaxanthin in feed ingredients. Agilent ZORBAX Eclipse DB-C 18 analytical column （4.6×150 mm, 5μm） was used and kept at 25 ℃. The mobile phase was acetonitrile ： methanol （v/v）=95 ： 5, and eluted compounds were detected by DAD absorbance （470 nm）. The flow rate was maintained at 1.0 mL·min^-1. The response of the method was linear over the range 1.0-20.0 μg·mL^-1 canthaxanthin assay solution （R^2=0.9998）. Recovery assays done with standard canthaxanthin to feed ingredient resulted in an average recovery of 103%. Variation coefficient was less than 3.53%. This method is proved to be simple, precise, sensitive and reproductive.     

四个观赏海棠品种光合特性比较研究

为比较引种观赏海棠品种间光合特性,以海棠粉芽、红宝石、凯尔斯和绚丽为试材,测定了净光合速率(P_n)、胞间CO₂浓度(C_i)、气孔导度(G_s)、蒸腾速率(T_r)等光合生理指标和光响应曲线。结果表明:凯尔斯净光合速率的日变化呈单峰型,但粉芽、红宝石和绚丽的净光合速率的日变化呈双峰型。胞间CO₂浓度日变化均呈V型曲线变化,均为早、晚高,中午低;气孔导度日变化曲线为单峰型和双峰型;蒸腾速率日变化曲线均为单峰型,出现峰值时间为10:00—14:00;水分利用效率日变化曲线呈多种类型,均表现为上午高、下午低;凯尔斯的最大净光合速率、光饱和点和表观量子效率最高,绚丽光补偿点最低,红宝石暗呼吸速率最低;4个观赏海棠品种净光合速率平均值为:凯尔斯(8.33 μmol·m^-2·s^-1)>绚丽(7.71 μmol·m^-2·s^-1)>粉芽(7.29 μmol·m^-2·s^-1)>红宝石(5.57 μmol·m^-2·s^-1)。综上,凯尔斯光合能力最强,且对光照要求低,可广泛栽植;红宝石光合能力最弱,且对光环境适应性较窄,可作为盆栽海棠新品种;粉芽表现为喜光型,应栽植在光照充足的地区;绚丽具有较强的弱光利用能力,可与其他树种混栽,栽植在光照较弱的地区。     

固体水对高原夏菜甘蓝幼苗生长与光合特性的影响

为获得高原夏菜生产中甘蓝育苗的最适固体水用量,通过田间随机区组排列试验设计的方法,以生产上常规的用水量为对照,研究了不同固体水用量对甘蓝幼苗生长发育的影响。研究得出：当固体水用量为400 ml/株时,甘蓝在最大叶长、最大叶宽、叶面积与冠根比等形态指标的表现上均优于其他处理,分别为7.41 cm、5.20 cm、26.24 cm²和69.51;同时幼苗光合速率、蒸腾速率、胞间CO₂和气孔导度数值最大,分别为27.86μmol·m^-2·s^-1、13.37 mmol·m^-2·s^-1、803μmol·m^-2·s^-1和734 mmol·m^-2·s^-1;同时幼苗代谢过程中的生理指标最优,可为甘蓝壮苗培育与水分高效利用提供技术参考。