自然低温胁迫下3种桉树的叶绿素荧光特性研究

对临安市3种桉树幼苗叶片叶绿素荧光特性进行研究,结果表明,自然低温下,各桉树表现出不同的适应性,总的来说,邓桉>柳桉>巨桉;自然低温(日最低气温-3.6℃)对柳桉和巨桉造成较大损害,而邓桉可通过维持相对较高的光化学效率,以及利用不断增加的qN来进行耗散,具有较强的抵抗低温胁迫伤害的能力。     

Effects of bFGF on brain edema,nerve function injury and autophagy related protein in rats with traumatic brain injury

AIM:To study the effects of basic fibroblast growth factor (bFGF) on brain edema, nerve function damage and autophagy related proteins in rats with head injury. METHODS:The rat model of craniocerebral injury (CI) was constructed. The rats were divided into control group, CI group, and low-, middle-and high-dose bFGF groups (n=10). The CI model was established in CI group, while the rats in control group were not given epidural impact. The rats in low-dose, middle-dose and high-dose bFGF groups were given bFGF at 2, 4 and 6 μg, respectively, by intraperitoneal injection after 30 min. The neurological function in the rats was evaluated by improved neurological function scoring. The rat brain tissues were taken, and the water content was detected. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β in the brain tissue were measured by ELISA. The malondialdehyde (MDA) content was analyzed by thiobarbituric acid method. The activity of superoxide dismutase (SOD) was examined by WST-8 assay. The glutathine peroxidase (GSH-Px) activity was detected by colorimetric method. The protein levels of autophagy related proteins LC3-Ⅱ and beclin-1 in the brain tissues were determined by Western blot. RESULTS:The neurological function score was increased significantly of the rats in CI group. The rat model of craniocerebral injury was successfully constructed. Neurological function scores in the rats in low-dose, middle-dose and high-dose bFGF groups were reduced, the water content of the brain tissue was also reduced (P<0.05). The levels of TNF-α, IL-6 and IL-1 β were decreased in the brain tissues (P<0.05), the content of MDA was declined (P<0.05), the activities of SOD and GSH-Px were increased (P<0.05), the protein levels of LC3-Ⅱ and beclin-1 were decreased, compared with the untreated rats in CI group (P<0.05). CONCLUSION:bFGF improves the nerve function of the rats with craniocerebral injury, reduces the water content of the brain tissue, reduces the expression of autophagic protein LC3-Ⅱ and beclin-1.The mechanism is related to the inhibition of inflammatory reaction and oxidative damage.     

不同剂量25羟基维生素D3对断奶前犊牛血液生化指标、抗氧化能力和免疫功能的影响

为研究不同剂量25羟基维生素D₃[25(OH)VD₃]对断奶前犊牛血液水平、抗氧化能力和免疫功能的影响,选取18 头健康状况良好的新生荷斯坦犊牛,随机分成3 组,每组6 头进行为期56 天的饲养试验。分为对照组[不添加25(OH)VD₃]、低剂量组[25(OH)VD₃添加量6 000 IU/头·天]和高剂量组[25(OH)VD₃添加量12 000 IU/头·天]。结果表明,与对照组相比,随着25(OH)VD₃添加剂量增加,血浆生长激素、胰岛素样生长因子-1、过氧化氢酶、超氧化物歧化酶、总抗氧化能力以及免疫球蛋白G(IgG)含量显著增加(P<0.05),而丙二醛含量随剂量增加而存在降低趋势(P=0.079)。与对照组和低剂量组相比,高剂量组血浆免疫球蛋白A(IgA)含量有增加趋势(P=0.059)。综上所述,断奶前犊牛饲喂高剂量25(OH)VD₃有利于促进体内生长激素和胰岛素样生长因子-1分泌,可提高犊牛抗氧化能力,增强免疫功能。     

低温胁迫对蓝莓枝条呼吸作用及生理生化指标的影响

为明确蓝莓枝条不同部位的耐低温能力,利用人工模拟低温胁迫的方法研究了蓝莓1年生枝条尖端、1年生枝条基端和2年生枝条对低温胁迫的生理响应。结果表明:低温胁迫下蓝莓不同部位枝条的各生理指标之间虽然具有一定的相关性,但不同生理指标的相关系数差异较大,即蓝莓枝条不同生理过程对低温的敏感性明显不同。其中,0℃时1年生枝条特别是其尖端的呼吸速率明显高于2年生枝条,但其呼吸作用对低温也特别敏感,当温度降低到-10℃时即均发生明显的降低,且1年生枝条尖端的降低幅度最大。另外,低温胁迫下1年生枝条尖端的丙二醛(MDA)含量和相对电导率增加幅度也明显大于1年生枝条基端和2年生枝条,即1年生枝条尖端对低温胁迫更为敏感。低温胁迫下不同部位枝条虽可以通过增加可溶性糖(SS)和可溶性蛋白(SP)等渗透调节物质,以及增强SOD和POD等抗氧化酶活性的方式来提高其抗寒能力,但当温度降低到-40℃时,不但抑制了蓝莓1年生枝条尖端可溶性蛋白的合成,并且1年生枝条尖端和基端的SOD活性较-20℃时也有不同程度的降低,即-40℃时1年生枝条特别是其尖端蛋白质合成的抑制以及抗氧化酶活性的降低可能是导致其蓝莓在我国北方大兴安岭地区易发生冻、干梢现象的主要原因。而1年生枝条基端和2年生枝条具有较强抗低温能力的原因除了其本身代谢活性较低,对低温不敏感外,低温下有效积累渗透调节物质和增强抗氧化酶的活性在降低其膜质过氧化程度和电解质外渗方面发挥了重要的作用。     

茶树小分子量热激蛋白基因CsHSP17.2的克隆与表达分析

[目的]进一步了解茶树小分子量热激蛋白基因CsHSP17.2在逆境胁迫条件下的分子生物学功能.[方法]利用RT-PCR技术从茶树‘迎霜’中克隆得到CsHSP1 7.2基因,运用生物信息学软件分析其核苷酸和编码蛋白,通过Real-timePCR分析其表达模式.[结果]该基因开放阅读框长度为453 bp,编码150个氨基酸,蛋白质相对分子质量为17.2×10a,理论等电点5.56;无信号肽位点,属于非分泌型蛋白;被定位于细胞质中.系统发育树分析表明,茶树CsHSP1 7.2与水稻(GenBank登录号:P27777)和花生(ABC41131)的进化关系较近,属于小分子量热激蛋白基因家族第Ⅰ亚族.qRT-PCR分析发现,茶树CsHSP17.2属于组成型基因;高温(38℃)处理1h能显著提高CsHSP17.2 mRNA的相对表达量(P＜0.05);干旱(100 g·L-1 PEG 6000)、高盐(200 mmol· L-1 NaCl)和外源脱落酸(200 mg· L-1 ABA)处理条件下,该基因的转录水平均出现不同程度的上调.[结论]克隆得到茶树‘迎霜’小分子量热激蛋白基因CsHSP17.2,其在花中表达量最高,且响应高温、干旱、高盐和外源脱落酸胁迫.     

凤庆茶叶种植与混林茶园生态系统研究

中国云南是世界茶树的原产地,而云南省凤庆县又是滇红的诞生地,具有悠久的茶树栽培种植历史,其混林茶园生态系统也具有较高的研究价值。本文通过对其茶叶种植史和混林茶园生态系统进行梳理和研究,厘清凤庆县茶叶种植的历史发展脉络,挖掘凤庆混林茶园生态系统的优势及其应用价值。     

移动通信基站在森林防火工作中的应用

移动通信基站基于卫星系统和通信系统的相关技术已相对成熟,在森林防火工作中已逐渐推广应用。本文根据工程实例,简要阐述了移动通信基站在森林防火工程项目中的应用。     

Demographic trends in Claremont California’s street tree population

The aim of this study was to quantify street tree population dynamics in the city of Claremont, CA. A repeated measures survey (2000 and 2014) based on a stratified random sampling approach across size classes and for the most abundant 21 species was analyzed to calculate removal, growth, and replacement planting rates. Demographic rates were estimated using a hierarchical Bayesian framework. The community-level (all species) median growth rate was 1.41% per year (95% CI: 1.21–1.65%) with Pinus brutia and Pistacia chinensis growing significantly faster than the community-level median. The community-level median removal rate was 1.03% per year (95% CI: 0.66–1.68%), with no significant differences between species and the community-level medium. Once removed, only 7.2% (95% CI: 4.4–12.9%) were replaced annually. Presence of overhead utility lines influenced tree removal rates while age, diameter-at-breast-height, and prior tree condition influenced tree growth. Overall live aboveground biomass in sampled sites was 713.29 Mg in 2000 and increased to 877.36 Mg by 2014. Biomass gain from growth outweighed loss from removals nearly three-fold; replacement contributed 0.5% of the total biomass gain. We conclude that to increase the resilience of the street tree population will require 1) an increase in percent of full stocking or biomass stock and 2) a shift in the species palette to favor species less vulnerable to pests and expected disturbance from climate change and 3) ongoing monitoring to detect departures from baseline demographic rates.     

基于SWOT分析的三明市全域森林康养产业发展对策

利用SWOT分析方法,对三明市发展全域森林康养产业进行优势、劣势、机遇和威胁分析,并针对存在的劣势和威胁提出了初步的对策与建议,以期为推进三明全域森林康养产业发展提供参考。     

落叶松油松人工混交林经营技术探讨

通过研究落叶松、油松混交林整个发育过程中不同阶段相应的经营管理措施，总结提出了一套切实可行的落叶松、油松混交林经营管理技术。其技术能有效提高林木生长速率，调整林分结构，优化树种组成，提高木材质量，为落叶松、油松混交林的经营管理提供技术支持。