不同施肥措施对毛金竹新竹产量的影响     

王海霞  程平  曾庆南 《世界竹藤通讯》2020,18(5):42

对毛金竹天然林和人工林进行施肥试验，研究不同施肥方式（竹腔施肥、土壤施肥以及复合施肥）对竹林产量的影响。结果显示，无论是人工林分还是天然林分，施肥措施均能有效提高林分的产量指标，其中复合施肥（竹腔+土壤施肥）效果最好，产量指标明显高于其他处理。  相似文献   

rbcL Gene Sequencing of Several Species Belonging to Morus and Their Genetic Relationship     

Lv Jinfeng  Zhou Chan  Zeng Xiu  Wang Yongliang  Wang Jieping  Wang Haiyan  Gu Shanlin  Wang Xiaoyan 《畜牧与饲料科学》2018,(3)

[Objective] The paper was to sequence the rbc L gene of several species belonging to Morus, and to explore the genetic relationship of Morus plants. [Method] Through DNA extraction, PCR amplification, sequencing, splicing and correction, a total of 56 rbc L gene sequences were obtained. [Result] Alignment results showed that there were 1 279 permutation sites in rbc L sequence of Morus plants; variable sites accounted for6.8% of the total sequence length, and the ratio of transition pairs to transversion pairs(R= si/sv) was 1.2. The rbc L sequence of Broussonetia papyrifera was selected as the outgroup, which was downloaded from Gen Bank. Genetic analysis results showed that M. alba, M. notabilis, M. rubra and Kuisang(the sample of this study) had distant relationship, and the other Morus plants had relatively close relationship. [Conclusion] The results lay a foundation for selection, identification and classification of Morus plants.  相似文献   

濒危珍稀植物半枫荷转录组中SSR位点分析     

叶兴状  杨先吉  王妙青  刘宝  范辉华  汤行昊  张国防  曾桂华  郑世群 《分子植物育种》2020,(5):1585-1592

分析半枫荷转录组中的SSR位点信息,并设计简单重复序列(SSR)引物,以期为半枫荷EST-SSR分子标记提供有力工具。利用MISA工具筛选了半枫荷转录组测序获得的77629条Unigenes,对其SSR位点信息进行了分析;在此基础上利用Primer 3.0设计SSR引物,并随机选择50对SSR引物对4株不同来源的半枫荷进行多态性扩增分析。在半枫荷的转录组中,共找到15041个SSRs,分布于10669条Unigenes,SSR位点发生频率为13.74%,含多个位点的序列数为3114,占SSRs位点总数的29.19%,以复合形式出现的位点数2044个,占SSRs位点总数的19.16%,SSRs的平均距离是3.2 kb。SSRs位点中二碱基重复是主要类型,占总SSRs的42.17%;其次是单碱基重复基序(38.25%)SSRs。所包含的重复基元中,单碱基重复基元A/T(5572),二碱基重复基元AG/CT(4845)是优势重复基元类型,分别占总SSRs的37.05%、32.21%。利用Primer 3共设计出28590对SSR引物。随机选择50对引物进行PCR扩增,其中44对(88.0%)扩增出清晰、可重复的条带,15对(34.1%)扩增条带表现出多态性。半枫荷转录组SSR位点出现频率高,类型丰富;大量的SSR为其遗传多样性分析、分子标记辅助育种和遗传图谱构建提供了丰富的候选分子标记。  相似文献   

基于数字图像测量技术的豆粕剪切变形特性   总被引：1，自引：1，他引：0  

曾长女  金南南  谷贺  周飞 《农业工程学报》2020,36(5):310-317

为了研究豆粕在剪切过程中的变形特性,利用基于数字图像测量技术的三轴仪,开展了豆粕三轴剪切试验。考虑了围压(25~100 kPa)、孔隙率(44.8%~50.9%)及颗粒破碎对豆粕强度及变形的影响,分析豆粕的不同变形发展阶段,并提出对应的应力应变模型,获得相关的强度和变形参数。试验结果表明,豆粕试样的应力应变曲线为软化型,随着围压增大,其强度软化性增大,剪胀性却逐渐减小。相同围压下,随着试样孔隙率减小,豆粕的峰值强度逐渐增大,剪胀角也逐渐增大,剪胀性表现越明显。不同破碎程度的豆粕颗粒分析结果对比发现,破碎后的豆粕峰值剪切强度增大,体变呈完全剪缩,围压越大剪缩现象越明显,这表明颗粒破碎对强度和变形影响很大,且围压对颗粒破碎的影响比孔隙率对颗粒破碎的影响大。最后,基于局部变形结果分析,将豆粕的应力应变曲线划分为3个阶段,即破坏前、破坏和残余阶段,提出了不同阶段对应的应力应变模型,获得了其强度和变形参数,得到破坏比为0.701 6。通过研究豆粕的剪切变形特性试验结果,获得了豆粕的强度、变形规律及其本构模型,可为粮仓结构的安全设计、优化分析及粮仓储粮等进一步数值仿真建模提供基础参考数据。  相似文献   

3种仿生药剂防治美国白蛾幼虫试验初报     

曾文豪  吕晓君  赵玉清  闵浩  黄芳  张新华  闵水发 《湖北林业科技》2020,49(5):39-42

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Pharmacokinetics of doxycycline in tilapia (Oreochromis aureus × Oreochromis niloticus) after intravenous and oral administration     

F. Yang  Z. L. Li  Q. Shan  Z. L. Zeng 《Journal of veterinary pharmacology and therapeutics》2014,37(4):388-393

The pharmacokinetics of doxycycline was studied in plasma after a single dose (20 mg/kg) of intravenous or oral administration to tilapia (Oreochromis aureus × Oreochromis niloticus) reared in fresh water at 24 °C. Plasma samples were collected from six fish per sampling point. Doxycycline concentrations were determined by high‐performance liquid chromatography with a 0.005 μg/mL limit of detection, then were subjected to noncompartmental analysis. Following oral administration, the double‐peak phenomenon was observed, and the first (C_max1) and second (C_max2) peaks were 1.99 ± 0.43 μg/mL at 2.0 h and 2.27 ± 0.38 μg/mL at 24.0 h, respectively. After the intravenous injection, a C_max2 (12.12 ± 1.97 μg/mL) was also observed, and initial concentration of 45.76 μg/mL, apparent elimination rate constant (λ_z) of 0.018 per h, apparent elimination half‐life (t_1/2λz) of 39.0 h, systemic total body clearance (Cl) of 41.28 mL/h/kg, volume of distribution (Vz) of 2323.21 mL/kg, and volume of distribution at steady‐state (Vss) of 1356.69 mL/kg were determined, respectively. While after oral administration, the λ_z, t_1/2λz, and bioavailability of doxycycline were 0.009 per h, 77.2 h, and 23.41%, respectively. It was shown that doxycycline was relatively slowly and incompletely absorbed, extensively distributed, and slowly eliminated in tilapia, in addition, doxycycline might undergo enterohepatic recycling in tilapia.  相似文献   

高职院校共享型专业教学资源库的构建与探索——以“汽车检测与维修技术”专业为例     

郝红梅  吴利平  李磊  邹修敏  陈丽  曾敏  陈晓燕  邹贵群 《南方农机》2021,(7):158-159

在大数据环境下,创建共享型专业教学资源库是各高职院校持续发展的建设重点,能够最大限度地满足学生自主学习的需要。本文着重阐述了共享型教学资源库的构建框架,详细分析了专业级资源与课程级资源、素材级资源等三个方面的构建内容,并以汽车检测与维修技术专业为例,说明共享型专业教学资源库的建设进程。  相似文献   

井冈山野生彩叶植物资源应用探讨     

曾以平  龙川 《江西林业科技》2021,49(3):46-49

为适应江西省林业"四化"建设的需要,在资源考察的基础上,对井冈山国家级自然保护区内的野生彩叶植物资源进行挖掘,分析这些资源的类型、特点,并对其园林景观配置应用进行了探讨.  相似文献   

Relating soil salinity,clay content and water vapour sorption isotherms     

Mingyuan Chen  Wenzhi Zeng  Emmanuel Arthur  Thomas Gaiser  Guoqing Lei  Yuanyuan Zha  Chang Ao  Yuanhao Fang  Jingwei Wu  Jiesheng Huang 《European Journal of Soil Science》2020,71(3):399-414

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Variation of intra‐aggregate organic carbon affects aggregate formation and stability during organic manure fertilization in a fluvo‐aquic soil     

Yunjie Wen  Yuefeng Tang  Jiong Wen  Qi Wang  Lingyu Bai  Yanan Wang  Shiming Su  Cuixia Wu  Jialong Lv  Xibai Zeng 《Soil Use and Management》2021,37(1):151-163

The aggregate formation and stability are controlled by the dynamics of soil organic matters (SOM), but how it is related to SOM chemical composition within different‐sized aggregates is largely unknown during manure fertilization. In this study, the variations of intra‐aggregate organic carbon (OC), including intra‐particulate organic matter (iPOM) and mineral‐associated organic matter, were quantitatively and qualitatively analysed, and then, their effects on aggregate formation and stability were assessed under four treatments: control (CK), mineral fertilizer (NPK), reduced manure (30%M) and manure fertilizers (M). Manure application (M) significantly increased macroaggregate proportion, mean weight diameter (MWD), and OC contents within different‐sized aggregates compared to CK, NPK, and 30%M. The OC accumulation of macroaggregate in M was attributed to OC content increase in silt plus clay subfraction rather than iPOM with more labile organic groups; oppositely, in microaggregate it was located in the relatively stable fine iPOM. The macroaggregate formation and stability were controlled by the fine iPOM within macroaggregates, whose abundant polysaccharide‐C and aliphatic‐C after manure fertilization advanced the microbial growth except for Gram‐positive bacteria, which further promoted macroaggregate formation and stability. The free silt plus clay fraction also affected macroaggregate formation and stability, and its polysaccharide‐C derived from microorganisms or decomposing SOM was positively associated with MWD and macroaggregate proportion. Because polysaccharide‐C can be easily associated with mineral particles, further improving micro‐ or macroaggregation. We conclude that continuous manure fertilization could increase labile SOM accumulation within aggregates and then facilitate microbial growth, which collectively are responsible for aggregate formation and stabilization.  相似文献