蔬菜一年三熟高效种植模式分析

绿色有机旱作农业是山西农业的传统特色。长治市属于典型的雨养农业、旱作农业区,长治市潞州区抓住绿色有机旱作农业的发展机遇,积极探索适宜该地区、具有区域特色的绿色有机旱作农业技术模式。该技术模式是通过合理的茬口安排,实行一年多茬栽培,“春白菜-甘蓝-秋白菜”是典型的一年三熟种植模式,通过对这种三收高效种植模式的种植方式、田间管理、病虫害防治等方面的分析,提出了实现高效种植的基本措施;按照绿色有机旱作标准制定种植方案,实现提质增效,通过提高复种指数,增加经济效益,为干旱地区绿色有机旱作农业发展提供技术参考。     

蔬菜一年三作高效种植模式

为提高土地复种指数,增加单位面积经济效益,对郯城当地的蔬菜种植模式进行了搭配探索和分析,通过多年实践经验,筛选出了一套经济合理的栽培模式——苦瓜、马铃薯、香菜一年三作高效栽培。文章重点从模式配置、配套技术、栽培技术、效益分析等几方面对该模式进行了总结。     

棉花中GhTFL1a和GhTFL1c基因的表达及启动子分析

从陆地棉中克隆了磷脂酰乙醇胺结合蛋白GhTFL1a和GhTFL1c基因,并对该基因进行表达分析、启动子预测和启动子活性研究。利用启动子分析软件PlantCARE预测得出,GhTFL1a启动子区域有脱落酸响应元件、干旱诱导的MYB结合位点和顶芽特异表达响应元件等;GhTFL1c启动子区域有乙烯响应元件、干旱诱导的MYB结合位点和水杨酸响应元件。因此,将pGhTFL1a和pGhTFL1c分别构建到启动子检测载体pBI121-GUS上形成融合表达载体,通过烟草瞬时转化检测得出这2个基因的启动子都具有活性。实时荧光定量PCR分析表明, GhTFL1a和GhTFL1c在光周期处理和不同材料的陆地棉(栽培种和半野生种)中表达模式呈相反趋势。GhTFL1a基因受脱落酸(abscisic acid, ABA)、水杨酸(salicylic acid, SA)和盐胁迫诱导,而GhTFL1c可以响应赤霉素(gibberellin, GA)、SA和ABA胁迫。研究结果初步表明,GhTFL1a和GhTFL1c可能参与了植物逆境胁迫脱落酸和水杨酸响应的调控,为在棉花中进一步阐明其功能奠定了基础。     

不同光照条件对脱镁叶绿酸钠光敏抑菌活性的影响

脱镁叶绿酸钠是叶绿素代谢中间产物脱镁叶绿酸a的水溶性钠盐,具有良好的光敏抑菌活性。为探索光照条件对其抑菌活性的影响,采用菌丝生长速率法,研究在不同光照度、光波长及光照时间条件下,脱镁叶绿酸钠对忽视拟盘多毛孢Pestalotiopsis neglecta的抑制作用。结果表明:20 mg/mL的脱镁叶绿酸钠在照度为2 000 lx的白光照射下对菌丝生长的抑制率为83.7%,在黑暗条件下抑制率为77.0%,表明光照对脱镁叶绿酸钠抑菌活性有显著影响 (P < 0.05);此外,白光的效果好于单色光;光照度及光照时间对抑菌活性也有显著影响,其中当照度为16 000 lx且光照时间为24 h时抑菌作用最强。     

Up-regulation of miR-181a attenuates releases of CSE-induced pro-inflammatory factors and expression of collagen IV,fibronectin and α-SMA in human bronchial epithelial cells

AIM: To investigate the effect and potential mechanism of microRNA-181a (miR-181a) on cigarette smoke extract (CSE)-induced the productions of pro-inflammatory factors and the expression of collagen IV, fibronectin and α-smooth muscle actin (α-SMA) in human bronchial epithelial cells (HBECs). METHODS: CSE-induced miR-181a expression was detected by RT-qPCR in the HBECs. After tansfected with miR-181a mimic, the releases of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and transforming growth factor-β1 (TGF-β1) were measured by ELISA, the protein expression of collagen IV, fibronectin and α-SMA was determined by Western blot. The activation of NF-κB/TGF-β1/Smad3 pathway was also evaluated by Western blot. RESULTS: CSE increased the levels of TNF-α, IL-1β, IL-6 and TGF-β1 and the expression of collagen IV, fibronectin and α-SMA, and decreased the expression of miR-181a in the HBECs (P<0.05). However, transfected with miR-181a mimic partially prevented the releases of TNF-α, IL-1β, IL-6 and TGF-β1, and inhibited the expression of collagen IV, fibronectin and α-SMA (P<0.05). Additionally, the activation of NF-κB/TGF-β1/Smad3 evoked by CSE was attenuated after transfected with miR-181a mimic. CONCLUSION: Up-regulation of miR-181a prevents the releases of CSE-induced pro-inflammatory factors and expression of collagen IV, fibronectin and α-SMA in the HBECs, and its mechanism may be related to the inhibition of NF-κB/TGF-β1/Smad3 pathway.     

苎麻C3H基因的克隆、生物信息学分析及表达分析

旨在为后期验证C3H基因编码蛋白功能并最终实现低木质素优良苎麻品种的基因工程育种奠定基础。基于苎麻高通量测序信息,利用RACE技术克隆C3H基因全长序列,对其进行生物信息学分析;并利用荧光定量技术对苎麻C3H的表达模式进行研究。获得了全长为1940 bp的苎麻C3H基因c DNA序列Bn C3H-1(Gen Bank登录号为KY078743)。Bn C3H-1基因编码蛋白理化性质和结构的分析表明,该基因编码一个含511个氨基酸,分子量为57.80 k D的亲水性蛋白,它可能定位在内质网上。氨基酸序列和结构分析显示Bn C3H-1有一个保守区域,即P450结构域。系统进化分析表明,该基因与巨桉和苦荞C3H基因具有很高的同源性。     

骑跨式机架的随机振动疲劳分析

为了提高矮化密植红枣收获机的工作性能,以骑跨式机架为研究对象,建立有限元模型。对机架进行模态分析,得出机架的固有频率与振型,并与各激励频率范围比较,可知机架的固有频率仍在发动机的激振频率范围之内。为避免机架产生共振,在发动机安装位置添加弹性元件,对机架采用减振方案的谐响应分析,计算得出应力、变形量变化曲线。结合机架结构材料的S-N曲线和线性累积损伤理论,对机架进行疲劳分析,验证机架的可靠性。研究结果表明:减振方案的谐响应分析使机架的最大变形量由2.977mm变到0.358mm,减小了87.974%,明显改善了机架的振动特性;在激振载荷的作用下对添加减振元件前后的机架分别计算疲劳寿命,得出添加减振元件后机架的疲劳寿命为1.84×10~8次,高于1.0×10~6次,满足机架疲劳强度设计要求。     

Development of a linear mixed-effects individual-tree basal area increment model for masson pine in Hunan Province,South-central China

ABSTRACT

An individual-tree basal area increment model was developed for masson pine based on 26276 observations of 13,138 trees in 987 sample plots from the 7th (2004), 8th (2009), and 9th (2014) Chinese National Forest Inventory in Hunan Province, South-central China. The model was built using a linear mixed-effects approach with sample plots included as random effects since the data have a hierarchical stochastic structure and biased estimates of the standard error of parameter estimates could be a consequence of applying ordinary least square (OLS) for regression. In addition, within-plot heteroscedasticity and autocorrelation were also considered. The final mixed-effects model was determined according to the Akaike information criterion (AIC), Bayesian information criterion (BIC), log-likelihood (Loglik), and the likelihoodratio test (LRT). The results revealed that initial diameter (DBH), the sum of the basal area (m²/ha) in trees with DBHs larger than the DBH of the subject tree (BAL), number of trees per hectare (NT), and elevation (EL) had a significant impact on individual-tree basal area increment. The mixed-effects model performed much better than the basic model produced using OLS. Additionally, the variance structure of the model errors was successfully modeled using the power function. However, the autocorrelation structures were not defined because there was no autocorrelation amongst the data. It is believed that the final model will contribute to the scientific management of the masson pine.     

纳米ZnO对浮萍（Lemna minor L.）的生态毒性及其聚集性和溶解性分析

纳米颗粒的大量生产和应用增加了其环境释放风险,为此以不同浓度的纳米ZnO（0、1、10mg·L-1和50mg·L-1）处理浮萍（LemnaminorL.）7d,分析了纳米颗粒对植物D665/D665a值（叶绿素与脱镁叶绿素的比率）以及超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和Na＋K＋-ATP酶（Na＋K＋-ATPase）活性的影响,并对纳米ZnO的聚集性与溶解性进行了测试。研究结果显示,浓度为50mg·L-1的纳米颗粒显著抑制D665/D665a值和Na＋K＋-ATPase活性,而抗氧化酶活性则显著升高;纳米颗粒在培养液中易发生聚集作用而沉积,12h后基本上完全沉积到底部。结果说明,50mg·L-1的纳米ZnO对浮萍产生了显著的胁迫作用,其对浮萍的毒性作用主要来源于其溶出的Zn2＋。     

杂色藻类褐藻素-叶绿素a/c结合蛋白的研究现状

褐藻素-叶绿素a／c结合蛋白（FCP）由核基因家族编码，镶嵌在杂色藻类的类囊体膜中，结合褐藻素、叶绿素a和叶绿素c，起着捕获并向两个光反应中心平均分配和传递光能的作用。前体N-末端存在一个信号肽和一个转运肽，成熟FCP具3个α-螺旋跨膜区，分子量在17～22kDa之间，结合叶绿素a的氨基酸高度保守，但结合褐藻素和叶绿素c的不太保守。fcp基因一般存在一个内含子，其蛋白编码区同源性达80％以上，而5’和3’非翻译区保守性相对较低。励基因表达量在红光及相对强光强下一般较高，且可能还存在日周变化．具4个α-螺旋的叶绿素a／b结合蛋白的第4个α-螺旋区缺失可能导致了具3个α-螺旋的FCP的产生。