The Influence of Carbon Dioxide or Ozone Concentration on Growth and Assimilate Partitioning in Seedlings of Nine Conifers     

Leiv M. Mortensen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):157-163

Abstract

Seedlings of nine different conifers were exposed to 355 and 730 μmol mol-1 CO₂, or low (> 15 nmol mol^?1) and elevated 0₃ concentration (70 nmol mol^?1) for 81–116 days. The experiments were conducted in growth chambers placed in a greenhouse. Increased CO₂ concentration enhanced the mean relative growth rate (RGR) and total plant dry weight by 4 and 33% in Larix leptolepis, by 4 and 38% in Larix sibirica, by 7 and 47% in Picea glauca and by 3 and 16% in Picea sitchensis, respectively. The growth rates and dry weights of Pimis contorta, Pinus mugo and Pseudotsuga menziesii were not significantly affected. Carbon dioxide enrichment enhanced RGR of two provenances of Picea abies by 4 and 6%, respectively, while a third provenance was unaffected. In Pimis sylvestris, only the RGR of one of three provenances was stimulated by CO₂ enrichment (4%).

After two growth seasons CO₂ enrichment enhanced RGR and total plant dry weight by 11 and 35% in Picea abies and by 12 and 36% in Pinus sylvestris, respectively. Elevated CO₂ decreased the shoot:root ratio in Larix leptolepis, and decreased the needlerstem ratio in Picea glauca, but increased it in Pseudotsuga menziesii.

Elevated O₃ significantly decreased the plant dry weight in Picea sitchensis, Pseudotsuga menziesii and in one of three provenances of Pinus sylvestris, while the other species and provenances were unaffected. Increased O₃ concentration increased the shoot:root dry weight ratio in one of three Picea abies provenances, in all three Pinus sylvestris provenances and in Pinus contorta. The needle:stem ratio was enhanced by O₃ in seven of the nine species. The O₃ exposure caused chlorosis of needles in all species except Pseudotsuga menziesii.  相似文献   

Antimicrobial minimum inhibitory concentration of Mycoplasma gallisepticum: a systematic review     

《The Journal of Applied Poultry Research》2021,30(2):100160

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Effects of soybean raffinose on growth performance,digestibility,humoral immunity and intestinal morphology of growing pigs     

Zhu Zeng  Yalin Zhang  Jun He  Jie Yu  Xiangbing Mao  Ping Zheng  Yuheng Luo  Junqiu Luo  Zhiqing Huang  Bing Yu  Daiwen Chen 《动物营养（英文）》2021,7(2):393

There are appreciable does of raffinose in soybean, but the impacts of raffinose on pigs are poorly investigated. We used 2 experiments to investigate the influence of soybean raffinose on growth performance, digestibility, humoral immunity and intestinal morphology of growing pigs. In Exp. 1, a total of 30 crossbred (Duroc × Landrace × Yorkshire) barrows (21.93 ± 0.43 kg) were randomly divided into 3 groups, and were fed with the control diet, the control diets supplemented with 0.2% and 0.5% raffinose, respectively, for 21 d. Results showed that the addition of 0.2% or 0.5% raffinose reduced (P < 0.05) average daily feed intake (ADFI), average daily gain (ADG) and nutrient digestibility, and dietary 0.5% raffinose increased the ratio of feed to gain (P < 0.05). For serum indexes, dietary 0.5% raffinose decreased growth hormone and increased glucagon-like peptide-2, immunoglobulin G, tumor necrosis factor-α (TNF-α) and interleukin-6 concentration (P < 0.05). In Exp. 2, a total of 24 crossbred barrows (38.41 ± 0.45 kg) were randomly divided into 3 groups, and were fed with the control diet (ad libitum), the raffinose diet (0.5% raffinose, ad libitum), and the control diet in the same amount as the raffinose group (feed-pair group) for 14 d, respectively. Compared with the control diet, dietary 0.5% raffinose decreased ADFI (P < 0.05). Intriguingly, the raffinose group had lower ADG than the feed-pair group, lower nutrient digestibility, lower amylase activity in duodenum, lower amylase, lipase and trypsin activities in jejunum and higher TNF-α concentration in serum compared with the other 2 groups, and a higher ratio of villus height to crypt depth compared with the control group (P < 0.05). These results showed that soybean raffinose could reduce feed voluntary intake and body gain while improving intestinal morphology without a significant negative influence on immunity. Taken together, dietary raffinose could decrease growth performance by reducing both feed intake and nutrient digestibility while inducing humoral immune response of growing pigs.  相似文献   

Effects of different dl‐selenomethionine and sodium selenite levels on growth performance,immune functions and serum thyroid hormones concentrations in broilers          下载免费PDF全文

Y. Wang  H. Wang  X. Zhan 《Journal of animal physiology and animal nutrition》2016,100(3):431-439

This trial was conducted in a 2 × 3 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different dl ‐selenomethionine (dl ‐Se‐Met) and sodium selenite (SS) levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers. A total of 840 Ross 308 broilers (7 days old) were allocated by body weight to seven treatments (three replicates of 40 birds each treatment) including (1) basal diet (containing 0.04 mg of selenium (Se)/kg; control) without supplementary Se; (2, 3 and 4) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as SS; (5, 6 and 7) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as dl ‐Se‐Met. The experiment lasted 42 days. The results revealed that dietary Se supplementation improved (p < 0.05) average daily gain, feed efficiency, immune organ index, serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) and triiodothyronine (T₃) concentrations and decreased (p < 0.01) thyroxine (T₄)/T₃ ratio in serum compared with the control. Broilers receiving the dl ‐Se‐Met‐supplemented diets had higher (p < 0.05) feed efficiency, thymus index, the amounts of IgA, IgG, IgM and T₃ as well as lower (p < 0.05) serum T₄ concentrations and T₄/T₃ ratio than those consuming the SS‐supplemented diets. Serum IgA and IgM levels of broilers fed 0.15 mg Se/kg were significantly higher (p < 0.05) than those of broilers fed 0.05 or 0.25 mg Se/kg. In summary, we concluded that dl ‐Se‐Met is more effective than SS in increasing immunity and promoting conversion of T₄ to T₃, thus providing an effective way to improve the growth performance of broilers. Besides, based on a consideration of all experiment indices, 0.15 mg Se/kg was suggested to be the optimal level of Se supplementation under the conditions of this study.  相似文献   

温度对绿豆芽苗菜产量和营养成分的影响     

佘冬芳  邹琴 《安徽农业科学》2007,35(11):3247-3247,3275

研究了不同温度对绿豆芽苗菜产量和营养成分的影响.结果表明:处理④绿豆芽苗菜生长速度最快且产量最高.其次是处理③,处理④与处理③的产量达显著差异,处理③、④与处理①、②的产量达极显著差异;营养成分中,Ve与胡萝卜素含量的大小是处理④＞处理③＞处理②、处理①;K+含量的大小是处理③＞处理④＞处理②=处理①.  相似文献   

Comparative pharmacokinetics of marbofloxacin in healthy and Mannheimia haemolytica infected calves     

Ismail M  El-Kattan YA 《Research in veterinary science》2007,82(3):398-404

The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance.  相似文献   

CO₂浓度增加对半干旱区马铃薯生长动态及产量、品质的影响     

张凯  王润元  王鹤龄  赵鸿  赵福年  齐月  陈斐  杨阳  雷俊 《干旱地区农业研究》2023,(4):238-246

为了解CO₂浓度升高条件下马铃薯生长动态及其产量、品质的变化特征,在典型半干旱区（甘肃定西）利用开顶式气室(OTC)试验平台,以马铃薯‘新大坪’为供试品种,设对照(390 μmol·mol^-1)和590 μmol·mol^-1共2个CO₂浓度梯度,开展CO₂浓度增加模拟试验。结果表明：CO₂浓度增加至590 μmol·mol^-1时,马铃薯发育加快,生育期提前,全生育期天数缩短3 d;CO₂浓度升高对马铃薯株高、叶面积指数、叶绿素含量和叶片水势有明显促进作用。随着生育进程的推移,马铃薯地上部干物质生产对CO₂浓度的响应值呈现先变大再变小的趋势。CO₂浓度增加促进了马铃薯块茎产量的提高,单株结薯数和单株薯块质量也有所增加。与对照相比,590 μmol·mol^-1CO₂处理马铃薯块茎水分、蛋白质、维生素C含量以及铁、锌、铜元素含量分别下降3.43%、11.78%、13.09%、25.58%、31.94%和9.76%,而粗淀粉、粗脂肪、粗纤维和还原糖含量分别增加10.56%、240.00%、14.28%、106.38%。  相似文献   

施用不同氮肥对盐碱地湖南稷子生产性能以及养分吸收的影响     

贾晓辉  张峰举  谢小伟  王斌  王腾飞  倪旺  陈月娟  许兴 《草地学报》2023,31(1):272-279

为探讨盐碱地湖南稷子(Echinochloa frumentacea)高效生产的最佳施氮种类和施氮量,采用单因素随机区组设计,通过在湖南稷子拔节期设置不施肥(CK)、尿素和硫酸铵(N1,N2)轻施肥(F1:50 kg·hm^-2)、中施肥(F2:100 kg·hm^-2)、重施肥处理(F3:150 kg·hm^-2),研究不同氮肥和施氮水平下湖南稷子田间农艺性状、养分吸收及氮肥利用率的变化,探讨盐碱地湖南稷子实现高效生产的适宜氮肥和施氮量。结果表明：与对照相比,施氮量为F2和F3时能够显著提高盐碱地湖南稷子产量及氮磷钾吸收量(P<0.05),植株不同部位氮含量上升,施氮量F3时能够显著提高氮肥利用效率(P<0.05),且同一施氮量下追施硫酸铵后湖南稷子产量、养分吸收及氮肥利用率均高于尿素。综上所述,氮肥追施量在150 kg·hm^-2时,有利于盐碱地湖南稷子的产量的提升和养分的吸收,且同一条件下追施硫酸铵较追施尿素效果显著。  相似文献   

多梯度氮磷添加对高寒草甸植物群落生物量与氮磷含量的影响     

刘艳  陈梦娇  郭童童  崔靖  李兰平  梁德飞  李永慧  张振华  朱小雪  任飞 《草地学报》2023,31(3):751-759

为研究不同梯度氮、磷单独及混合添加对高寒草甸植物群落生物量、植物养分含量及化学计量比的影响,本实验分析了青海省门源县典型高寒草甸植物群落地上总生物量,功能群水平地上生物量,植物全氮、全磷含量及氮磷比对多梯度氮、磷添加的响应情况。结果表明：氮、磷添加均对群落地上生物量影响极显著(P<0.001);氮添加对禾草类和豆科生物量影响极显著(P<0.001);磷添加对禾草类和莎草类生物量影响极显著(P<0.001);氮磷交互作用对豆科和莎草类生物量影响显著(P<0.05)。群落水平上,氮添加显著提高了植物全氮含量,对植物氮磷比(N∶P)有正效应,磷添加显著提高了植物全磷含量,对植物N∶P有负效应,植物全磷对N∶P的负效应大于全氮对N∶P的正效应。本研究表明氮、磷添加可能会使高寒草甸植物群落组成和植物养分含量发生改变,植物群落逐渐向禾草类发展;此外,高寒草甸植物生长趋向于受氮磷共同限制。  相似文献   

牛奶中褪黑素含量的检测方法     

沈紫霞  常毅  刘巧香  郭刚  马慧  李有志  廖晨星  刘国世 《中国乳业》2023,(2):10-14

褪黑素作为一种多功能活性因子,在畜牧生产中具有十分重要的作用。近年来,有关天然高褪黑素奶的研究大规模开展,对奶中褪黑素含量测定需求也有所增加。目前比较常见的褪黑素检测方法有气相色谱法（GC）、气相色谱-质谱联用法（GC-MS）、高效液相色谱法（HPLC）、高效液相色谱-质谱联用法（LC-MS）、放射免疫测定法（RIA）、酶联免疫吸附测定法（ELISA）、紫外分光光度法（UV）。本文从原理、特点及优缺点等方面对这几种方法展开介绍,并对各方法的应用进行简单的比较,为后续相关研究与应用提供一定参考。  相似文献