我国作物病虫害生物防治研究与应用最新进展

本文总结了近5年来我国在作物病虫害生物防治研究和应用方面的最新进展, 包括作物害虫、病害(真菌、细菌和病毒病)和线虫的生物防治、植物免疫和昆虫性信息素的研究和应用, 以及新方法和新技术在作物病虫控制中的应用。同时, 与国外的研究进展进行了比较, 指出了存在的主要问题、发展趋势与对策建议。     

Indexes optimization of outburst forecast while a rock cross-cut coal is uncovered by pulsed water jet

To obtain the best outburst prediction index of rock cross-cut coal uncovering slotted by pulsed water jet,the effects of the rigidity coefficient’s measured value and the initial velocity of gas diffusion to the integrative indexes D and K are analyzed based on the dynamic evolution of coal crake field under water jet. Thus the integrative indexes D and K are excluded. A grey relation model of outburst prediction indexes(K1,S and P)from 7 coal mine’ rock cross-cut coal uncovering in Chongqing,Sichuan and Henan is set up. And the grey relation degrees of the 3 prediction indexes to outburst hazard are calculated by using grey relational analysis method. The results show that the outburst hazard can be more accurately reflected by the cuttings desorption index K1 when a cross-cut coal uncovering slotted by pulsed water jet,and it should be considered as the best outburst prediction index.     

植物基因印迹及其对种子发育的影响

基因印迹最先发现于哺乳动物的胚胎发育中,近些年研究表明也存在植物种子发育中.基因印迹成为当前植物种子发育生物学的研究热点.从印迹基因、印迹机制及其对植物种子发育的影响等方面综述了植物种子发育中基因印迹的研究进展,并提出研究中存在的问题及其解决对策,旨在为今后相关研究提供参考.     

铁皮石斛的组培技术研究

为了研究铁皮石斛最佳的组织培养方法,本试验以铁皮石斛带节茎段作为外植体,探寻铁皮石斛的最佳基本培养基,最优消毒时间,以及不同浓度的NAA和6-BA对腋芽诱导、丛芽增殖、生根壮苗的影响.结果表明:以铁皮石斛带节茎段作外植体时,最佳的基本培养基是1/2MS培养基,在1‰HgCl2中浸泡消毒的最优时间为10 min;诱导腋芽时以1/2MS+10 g·L-1蔗糖+0.6 mg·L-1 NAA+1.5 mg·L-16-BA为最佳培养基;诱导丛芽增殖的最佳培养基为1/2MS+0.6 mg·L-1 NAA+1.5 mg·L-16-BA;诱导生根的最佳培养基为1/2MS+0.5 mg·L-1 IBA+0.9 mg·L-1 NAA.     

垦丰11大豆品种高温胁迫响应研究

以垦丰11为试验材料,针对黑龙江省大豆生态区域特点,选择4个不同生态区的土壤在哈尔滨市进行盆栽试验,通过大棚和大棚中设立小棚实现高温和异常高温,研究大豆对高温胁迫的响应。结果表明:增加温度提高了大豆的植株高度;节数没有变化,平均节间距离加大,温度越高增加得越明显;大豆从出苗~鼓粒增加温度单株产量均下降;但是从出苗~开花高温百粒重增加,特别是异常高温百粒重增加得更明显。     

杭州城区高架桥绿化现状与植物的选择

分析了杭州市城区高架桥(含立交桥，下同)绿化植物品种，探讨了高架桥绿化植物品种的选择方法，并提出了高架桥绿化养护保水第一的观点。     

嵌合O型口蹄疫病毒多表位基因猪细小病毒VLPs载体疫苗的构建

综合运用生物信息学和分子生物学技术,模拟PPV VP2蛋白表面不同Loop区插入O型FMDV VP1蛋白上多表位基因(VP1:21～40、141～160和200～213残基)空间构象,并在VP2 N端引入通用型辅助性T淋巴细胞表位(PADRE),人工合成嵌合基因并克隆到杆状病毒转移载体pFastBac HTA中,转化E.coli DH10Bac感受态细胞,经三抗筛选,获得重组杆状病毒表达质粒rBac-FMDV VP1∶PPV VP2,用脂质体法转染Sf9细胞。对rBac-FMDVVP1∶PPV VP2感染的Sf9细胞,用间接免疫荧光试验(IFA)检测,具有特异性荧光;用Western-blotting分析,在64 000处出现一条特异蛋白条带;电镜观察,重组VP2蛋白能够自主组装成病毒样颗粒。红细胞凝集试验证实,表达的嵌合蛋白PPV∶VP2-FMDV∶VP1具有与全病毒类似的血凝活性。     

联合收割机割刀驱动行星轮系多目标优化设计

针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。     

农业电商扶贫可以提升农户的可持续生计吗?——基于农产品上行视角

从农户的发展能力、经济能力和社交能力3方面选取16个指标,运用组合赋权法确定指标权重,构建农户可持续生计评价指标体系,并基于此评估农业电商扶贫的成效。结合文献与实地调研获取的湖北省252份农户(含贫困户与脱贫户)调查数据,先对农户的可持续生计进行测度,然后运用OLS、2SLS、LIML、IVGMM和IV-Tobit共5种回归方法对农业电商扶贫中影响农户可持续生计的因素进行分析,并采用ISM模型分析论证了各影响因素的关联性质和层次结构。结果显示:样本农户的可持续生计水平一般,发展能力和经济能力相对较高,社交能力相对较弱,但这3种能力均未达到中等水平,有待提高。是否参与农业电商、亲戚中有无村干部、公共服务、政府支持和产业基础在农业电商扶贫中对农户的可持续生计具有显著(P<0.1)影响。是否参与农业电商和亲戚中有无村干部是表层直接影响因素,政府支持和产业基础是中层间接影响因素,公共服务是底层因素。因素之间的逻辑层次结构可用“单驱动、双路径”来概括。     

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.