花生收获机传动系统的运动机理分析与参数优化

通过对4H-2型花生收获机传动系统的运动机理分析,得到了该收获机传动部件的运动规律以及传动部件中主要参数的关系表达式。以提高作业质量、延长机具寿命、简化结构布局、确保动力传动的高效可靠为目标,建立了传动机构的优化模型。利用Matlab等相关软件,对4H-2型花生收获机的传动机构进行了优化分析,确定了主要杆件的尺寸,提高了4H-2型花生收获机的性能与工作可靠性,降低了造价。     

计算机病毒的预防和杀毒策略

针时计算机病毒的种类,常见的传播方式,命名规则以及命名解释进行了介绍,并根据其传播方式,介绍了相应的防毒措施和有效的顽固性病毒杀毒策略。按照所介绍的知识,能够防止绝大部分病毒时网络计算机的入侵,并能够在杀毒软件无效的情况下,对顽固性病毒进行彻底地查杀。     

来源于新疆的3 个苹果褪绿叶斑病毒分离物的分子变异研究

Apple chlorotic leaf spot virus (ACLSV) isolates from Korla pear (KI-2), New pear no. 7 (XI-1) and Red Fuji apple (API-4) were collected from XinJiang and characterized by analyzing sequences of their near genomic 3忆-terminal. The RT-PCR products were cloned, and analyzed by single-strand conforma-tion polymorphism (SSCP). Eight out of 39 collected positive clones showing different SSCP patterns were sequenced. The results showed that the amplified products had sizes ranging 676 - 703 bp, including partial coat protein (CP) gene (506 bp, accounts for 87% of the complete cp gene) and 3忆-terminal non-coding re-gion (3忆NCR) sequences. The cp gene sequences from isolate KI-2 showed a high intra-isolate divergence,with 84. 8% - 85. 4% identities at the nucleotide (nt) level, and the intra-isolate identities were 99. 8 % and 92.5% - 99. 8 % for isolate XI-1 and API-4, respectively. Phylogenetic analysis on the nt sequences of cpgene showed that the analyzed ACLSV variants from three isolates fell into two different clusters. A variant KI-2-6 from KI-2 was clustered into a group with an apple isolate aclsv-c from China and a plum isolated from France, and all other variants fell into a large cluster. The 3忆NCR sequences of these variants were identical ranging 80. 6% - 100 % .     

山西苹果茎痘病毒遗传多样性分析

苹果茎痘病毒是苹果安全生产的巨大威胁,严重影响苹果产量和质量。探讨苹果茎痘病毒(Apple stem pitting virus, ASPV)在山西省的分布、变异和多样性,可为制定可持续的病毒管理策略提供理论依据。从山西省11个地区采集苹果叶片样品进行RT-PCR检测。结合在线数据库,利用相关软件对文中研究获得的序列进行系统发育、遗传多样性、重组以及种群遗传分化等分析。RT-PCR检测结果显示从山西省11个地区采集的409份苹果叶片样品中,ASPV的检出率为36.33%(临漪)至55.37%(平遥)。选择15个ASPV检测为阳性的样品,分别克隆其CP基因并与22个不同的ASPV分离物进行核苷酸和氨基酸一致性分析,发现37个ASPV分离物的核酸一致率为70.27～96.31%,氨基酸一致率为37.04～96.64%,其中,Shanxi-2与JX673826.1的核酸一致率最高,为90.86%, Shanxi-2与MN617853.1的核酸一致率最低,为70.40%。基于CP的进化树分析结果显示37个ASPV分离物被划分为2个进化群体。遗传多样性分析结果表明ASPV种群发生了收缩,且在两个...     

湖南柑橘衰退病调查分析及弱毒系筛选

 The investigation showed that stem-pitting Citrus tristeza virus (CTV)occurred commonly in citrus production areas in several varieties of Hunan Province. Accurate detection of CTV strains was performed by p23/PCR method, PCR and the results indicated that the most samples were infected with several CTV isolates. Three mild strains were isolated and their pathogenicity was identified by biological identification, it indicated that p23/PCR groups had uniformity with the pathogenicity of CTV isolates. Furthermore, three mild isolates were tested in the cross protection by analysis of biological symptoms and composition of p23 gene. Different protecting effects were observed among these strains and W17 mild isolate was effective.     

鸭病毒性肝炎病毒JH2株感染雏鸭血清生化指标的动态变化

用1型鸭肝炎病毒山东分离株JH2人工感染3日龄健康樱桃谷雏鸭,对接种后1～5 d的血清酶、血糖及血脂等多项血清生化指标进行测定,结果表明:鸭肝炎病毒感染雏鸭1～2 d内丙氨酸氨基转移酶、天门冬氨酸氨基转移酶活性较未攻毒的对照组极显著升高:碱性磷酸酶活性在接种后2～3 d内与对照组差异极显著;接种后1～5 d攻毒组总胆红素和间接胆红素的含量均低干对照组,其中接种后1、3、4 d时差异显著;攻毒组胆碱脂酶和甘油三脂在接种后1～2 d内较对照组极显著升高,胆固醇在整个试验中无明显变化;谷氨酰胺转移酶活性在接种后1～4 d内较对照组有极显著升高;乳酸脱氢酶活性1～3 d内较对照组极显著升高,而肌酸激酶活性虽高于对照组,但差异不显著;雏鸭在接种后1～3 d内表现出明显的低尿酸血症,接种后1 d肌酐含量较对照组显著升高;α-淀粉酶活性呈逐渐升高的趋势,但均低于对照组,接种后1～2d与对照组差异极显著:攻毒组总蛋白、白蛋白和球蛋白在整个试验期间表现为先升高后降低的趋势,血清葡萄糖在接种后1 d降至最低,与对照组差异极显著.     

Characterization of a pothos (Scindapsus aureus) virus with unusual properties

A virus for which the name of pothos latent virus (PoLV) is proposed, was isolated by inoculation of sap from symptomless plants ofScindapsus aureus. PoLV had isometric particlesc. 30 nm in diameter, a monopartite genome consisting of a non polyadenylated, single-stranded RNA moleculec. 4,300 nucleotides in length, constitutingc. 17% of the particle weight, and a single type of coat protein subunit with aM _r ofc. 40,000 Daltons. The biological properties (host range reactions) of PoLV resembled those ofTombusviridae for it infected most of the artificial hosts locally, inducing symptoms recalling those elicited by several species of the above family. Like tombus- and carmoviruses, PoLV had two subgenomic RNAs which, however, differed in size from those of both genera. The dsRNA pattern was also distinctly different. Cytopathological features recalled those of tombusviruses except for the lack of multivesicular inclusion bodies. PoLV was serologically related to, but distinct from twoCarmovirus (i.e., galinsoga mosaic and Ahlum waterborne viruses) and threeTombusvirus species (i.e. eggplant mottled crinkle, Sikte waterborne and Lato river viruses). Thus, PoLV had properties somewhat intermediate between those ofTombusvirus andCarmovirus genera but bridged the two taxa through the serological relationship with some of their species. The taxonomic position of PoLV is still undetermined. It must await the results of molecular investigations now underway.     

二温式多重RT-PCR同删两种主要兰花病毒的研究

根据建兰花叶病毒(Cymbidium mosaic virus,Cy MV)和齿兰环斑病毒(Odontoglossum ringspot virus,ORSV)两种主要兰花病毒的保守序列设计特异性引物,建立了二温式多重RT-PCR同时检测两种病毒的检测方法。用该方法对感染两种病毒的植株总RNA模板进行扩增,结果同时得到2条大小与实验设计相符的769bp(Cy MV)、1000bp(ORSV)的特异性扩增带。用该方法对随机抽取的39个蝴蝶兰样品进行检测,结果11个样品检测出Cy MV,阳性率28.2%;24个样品检测出ORSV,阳性率61.5%;6个样品同时检测出两种病毒。     

小麦条锈菌鉴别寄主中4抗条锈性的转录组学分析

为解析中4的抗条锈性分子机制,通过转录组测序,以侵染0h为对照,分析条锈菌侵染12、24和48 h后差异基因的表达情况.结果 共获得5151个持续上调表达差异基因,其中,4482个基因获得定位信息(A、B、D染色体组各占30.75％、35.27％、33.98％),669个为新基因(无法确定其染色体位置).GO功能注释分...     

侵染广西番茄的番茄黄化曲叶病毒的分子鉴定

番茄黄化曲叶病毒病是番茄生产上的毁灭性病害,严重影响番茄产量及品质。2019年从广西百色市采集疑似番茄黄化曲叶病叶片样品,采用滚环扩增(RCA)及基因克隆等方法,获得了4个烟粉虱传双生病毒的全基因序列,4个分离物的全长序列分别为2 776、2 781、2 752、2 781 bp,均编码6个开放阅读框;核苷酸相似性比较发现,4个分离物彼此间的相似性均在90%以上,与已报道的番茄黄化曲叶病毒Tomato yellow leaf curl virus (TYLCV)各分离物间的相似性也在91%以上;系统进化分析表明,TYLCV广西分离物BS-2和BS-4与TYLCV-Hunan、BS-1和BS-3与TYLCV-YN6553等分离物处于独立的小分支,说明TYLCV广西分离物与TYLCV-Hunan、TYLCV-YN6553具有较近的亲缘关系。本研究首次报道TYLCV在广西发生。