大樱桃贮藏保鲜技术研究进展

大樱桃营养丰富,色泽鲜艳,口感香甜,具有补中益气、祛风湿等功效,非常受市场欢迎。但由于大樱桃采摘后易软化腐败,不易保存,因此需要加强大樱桃保鲜研究。本文介绍了大樱桃采前因素对贮藏品质的影响及控制措施,并总结了大樱桃低温保鲜、气调保鲜、涂膜保鲜、减压保鲜、辐照保鲜及保鲜剂处理等保鲜技术的研究进展,以期促进大樱桃保鲜技术的发展,减少腐损率,提高经济效益。     

湖南三种不同嫩度工夫红茶香气品质比较分析

对湖南红茶标准样及安化群体种与黄金茶等三种不同嫩度红茶样进行了香气感官品质评价和成分分析,结果表明:芽头红茶样品中醇类含量占比最高,呈现出馥郁高长的鲜甜香;一芽一叶红茶样品中醇类、醛类、酮类和酯类含量居中,多表现为纯正较浓的甜香;一芽二叶茶样样本间差异较大,碳氢化合物和酯类化合物在标准样品中占比较高,其花香明显,在安化群体和黄金茶红茶样品中占比较低,表现为甜香纯正.试验结果可为湖南红茶原料嫩度选择提供参考.     

水稻OsABCC10基因的克隆及其功能分析

ABCC蛋白为ABC转运蛋白超家族中的一个亚家族,主要参与将各种分子从细胞质输出到外部介质或细胞器基质的过程。为了研究OsABCC10基因是否参与水稻Na+的运输,本研究从水稻基因组中克隆出OsABCC10基因,该基因cDNA全长4539 bp,编码1513个氨基酸。OsABCC10基因表达分析发现,其主要在水稻根中表达,表达量随盐处理浓度的升高及处理时间的延长而增强,表明OsABCC10基因的表达受盐胁迫的调控。亚细胞定位分析证实OsABCC10定位于液泡膜上。盐胁迫条件下,与野生型相比,osabcc10突变体表现出对盐更敏感,而且木质部汁液中Na+浓度升高。然而,当OsABCC10基因导入野生型酵母菌株BY4741表达时,与对照组实验相比,有OsABCC10表达的酵母细胞的生长受到了抑制。该结果与植物生理实验结果相反,这可能与OsABCC10蛋白在酵母中的定位有关。本研究初步推测OsABCC10基因参与水稻Na^+的转运,是一个新的耐盐基因。     

防御信号途径在B型烟粉虱取食烟草诱导抗蚜防御中的作用

B型烟粉虱取食能够诱导烟草产生对烟蚜的抗性反应,为了明确水杨酸和茉莉酸防御信号途径与烟粉虱诱导抗蚜防御之间的关系,采用生化分析、实时定量PCR、蚜虫生物活性测定等方法比较了烟粉虱若虫取食对烟草水杨酸、茉莉酸含量、通路下游防御基因表达水平的影响及外源水杨酸、茉莉酸对烟蚜生长发育的影响。结果显示：烟粉虱侵染能够显著激活水杨酸防御途径,在取食15天后,水杨酸水平较对照升高1.40倍,水杨酸下游防御基因PR-1a及PR-2a分别较对照升高3.22和0.74倍;然而烟粉虱侵染后烟草叶片茉莉酸含量与对照相比无显著变化,JA下游防御基因PI-II和TPI的转录水平分别较对照降低73.91%和56.73%。生测结果显示,外源施用水杨酸对烟蚜的存活率和相对平均生长率具有显著不利影响。烟草叶片施用1 mmol/L水杨酸后,蚜虫的存活率及相对生长率分别较对照降低43.2%和11.54%;然而喷施茉莉酸甲酯对蚜虫的生长发育无不利影响。上述结果表明,水杨酸介导的防御应答在B型烟粉虱取食诱导烟草的抗蚜防御中起重要作用。     

Identification of a cell-wall peptidase (NlpC/P60) from Nocardia seriolae which induces apoptosis in fathead minnow cells

Nocardia seriolae, a Gram-positive bacterium, is the main pathogen of fish nocardiosis. Protein NlpC/P60 is a cell-wall peptidase and a potential virulence factor of N. seriolae. Subcellular localization research revealed that both NlpC/P60-GFP and NlpC/P60Δsig-GFP fusion proteins were evenly distributed in the whole cell of fathead minnow (FHM) cells. Furthermore, typical apoptotic features, such as nuclear pyrosis and apoptotic bodies, were observed in the transfected FHM cells and grouper spleen cells by the overexpression of protein NlpC/P60. Then, quantitative assays of mitochondrial membrane potential (ΔΨm) value, caspase-3 activity and apoptosis-related gene (Bax, BNIP3, TNF1 and TNF6) mRNA expression were conducted. The results showed that ΔΨm was decreased, caspase-3 was significantly activated, and the mRNA expression of pro-apoptotic genes (Bax and BNIP3) and tumour necrosis factors (TNF1 and TNF6) was up-regulated in NlpC/P60-overexpressed cells. Taken together, the results indicated that the protein NlpC/P60 of N. seriolae might involve in apoptosis regulation. This study may lay the foundation for further study on the function of N. seriolae NlpC/P60 and promote the understanding of the virulence factors and pathogenic mechanism of N. seriolae.     

网室内棉花不育系蜜蜂授粉试验研究

本研究在网室内利用蜜蜂为6个棉花不育系材料授粉，以人工授粉作为对照，研究蜜蜂授粉和人工授粉在农艺性状等指标上的差异。结果表明，蜜蜂授粉和人工授粉的单株结铃数和空果枝数有极显著差异；不同不育系的单株结铃数差异极显著，果枝数有显著差异。晋56-1A、晋56-3A、晋56-6A的单株结铃数在蜜蜂授粉和人工授粉间有显著性差异，晋56-2A和晋56-5A的单株结铃数在不同授粉方式下有极显著差异；晋56-4A和晋56-6A的空果枝数有极显著差异。室内考种表明，蜜蜂授粉的衣分范围为26.3%～39.6%，人工授粉的衣分为29.4%～35.3%，人工授粉衣分范围相对较小。人工授粉的单铃籽粒数、制种产量均比蜜蜂授粉大，铃重、籽指、发芽率相差不大。蜜蜂授粉制种产量达人工授粉的80%左右；而制种成本可节约50%以上。因此，选择强群势蜂群、适时有效的虫害管理等措施，可提高棉花不育系制种效率，对棉花“三系”的发展有重要的推动作用。     

Effect of miR-29b-mediated TGF-β/Smad signaling pathway on progression of hepatic fibrosis in rats

AIM: To investigate the role of microRNA-29b (miR-29b)-mediated TGF-β/Smad signaling pathway in the activation of hepatic stellate cells (HSC) and its effect on the progression of hepatic fibrosis in rats.METHODS: Hepatic liver fibrosis rat model was established, and its HSC were isolated. Normal rat HSC were also obtained and identified in vitro. RT-qPCR and Western blot were used to detect the alterations of miR-29b, TGF-β/Smad signaling pathway-related proteins and liver fibrosis marker proteins in the acquired cells. Finally, the direct targeting binding of miR-29b to TGF-β1 was identified by dual-luciferase reporter assay system.RESULTS: With the activation of HSC, the expression of miR-29b gradually decreased (P<0.01), while the expression of collagen type I and α-smooth muscle actin gradually increased (P<0.01). At the same time, the expression of Smad2/3/4 was significantly increased, and the expression of Smad7 was significantly decreased (P<0.01). Dual-luciferase reporter assay showed that miR-29b bound directly to "UCUCUCCGU" in the 3'UTR of TGF-β1, indicating that TGF-β1 was a downstream target gene of miR-29b.CONCLUSION: miR-29b may be involved in the inhibition of HSC activation and migration, thereby inhibiting the process of liver fibrosis. The biological function of miR-29b may be through the direct targeting of TGF-β1, thus regulating and inhibiting the TGF-β/Smad signaling pathway.     

拖拉机电液悬挂系统及控制技术

针对传统拖拉机机械式三点悬挂的功能局限性问题，采用智能控制技术，实现了电液系统的信息集成，特别是对于负载传感液压系统及控制器研制了新的技术方案，通过建模与仿真，提出了基于CAN通讯的设计方法，研制了控制面板、控制器、传感器、液压系统和悬挂机构，经试验验证，实现了拖拉机悬挂系统优化提升，特别适合拖拉机的复合农田作业。      

基于CiteSpace可视化分析的茶叶香气研究进展

以1979—2019年WOS(Web of science)和CNKI(China national knowledge infrastructure)收录的茶叶香气品质相关文献为研究对象,采用CiteSpace文献计量方法分别从年代、作者、机构、国家、研究热点、演进趋势等方面进行归纳统计分析。结果表明,2006年以后相关研究文献呈显著增长趋势,目前已形成稳定的核心作者群,但各群体间的合作研究相对较少;在该研究领域,我国影响力最大,其次是日本和美国;热点研究内容主要集中在香气形成机理、香气物质提取方法、检测手段及关键香气物质等方面。综上结果,结合时区图谱,进一步指出茶叶香气的研究历程及目前所处的发展阶段。     

一起未附检疫证明运输动物产品案的分析

2017年5月,A市动物卫生监督机构经A市交警支队通报告知,范×涉嫌运输未附检疫证明的动物产品。经立案调查,认定当事人违法事实存在,按照《动物防疫法》第四十三条和第七十八条的规定,依法给予了行政处罚。本文对该案的适格主体、违法事实、法律适用、程序、证据等方面进行点评,分析了办案过程中存在的案件来源认定缺少支撑,运输价格认定证据单薄,涉案物品处置程序缺失,执法文书送达时机不当等问题。本文也对"有证未附与无证可附"主要区别及不同案情中涉案物品处置方式和结果进行梳理,以期为官方兽医严格依法行政提供参考。