首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21篇
  免费   0篇
林业   2篇
农学   3篇
基础科学   4篇
  1篇
综合类   8篇
植物保护   3篇
  2012年   1篇
  2011年   5篇
  2009年   1篇
  2008年   3篇
  2006年   1篇
  2004年   4篇
  2003年   1篇
  1998年   2篇
  1996年   1篇
  1993年   2篇
排序方式: 共有21条查询结果,搜索用时 31 毫秒
1.
The effects of various salinities and desalination on seed germination of six annual glycophytes (Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum) were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations (0 mM, as the control, and 50, 100, 200 and 300 mM) were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels (50 mM) significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity (>200 mM) led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages (salinity stress and desalination) of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species (A. sieversiana, Ch. virgata and Ch. acuminatum) showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ’salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.  相似文献   
2.
在刚性面层下设置一道性能良好的保温层来防止基土冻结,可以从根本上解决冻胀破坏的问题。这种带保温层的刚性护面渠道称为保温型刚性护面渠道,根据热工原理,提出了保温型刚性护面渠道横断面设计在构造方面的要求,进一步推导出计算保温层厚度的有关公式,并给出算例,还指出了需要进一步研究和探讨的问题。  相似文献   
3.
PEG处理葡萄试管苗生理反应及叶片组织形态研究   总被引:2,自引:0,他引:2  
应用不同浓度的聚乙二醇(PEG10000)处理红地球葡萄生根试管苗,在造成一定程度水分亏缺的情况下,观察葡萄试管苗的生理反应和植株生长、叶片形态解剖结构的变化。结果表明:在PEG处理下,葡萄生长发育迟滞,植株节间变短,株高变矮,但发根数量增加,根变长;新生叶片与对照比,叶片小而皱缩,气孔指数降低,上皮细胞排列更紧凑;同时葡萄试管苗脯氨酸的积累和内源ABA迅速增加。说明在一定强度的水分胁迫下,葡萄试管苗叶片的发育向增强其耐旱能力的方向进行,其渗透调节物质的积累是葡萄试管苗对长期水分胁迫的生理反应。  相似文献   
4.
膜下滴灌毛管配置对水分运移及棉花增产效应的影响   总被引:2,自引:2,他引:2  
研究了棉花膜下滴灌在不同毛管配置、不同滴头流量下在不同质地土壤中水分运移规律及对棉花生长发育、增产效应的关系。结果表明:砂性土壤适宜于以一管二行配置水产比高、增产效果好,从产量结构及产量看,以2.8L/h滴头流量产量最高;粘土以一管四行配置增产效果好、经济效益高,以2.1L/h滴头流量产量最高。  相似文献   
5.
讨论了在有限深透水地基上修建三边用土坝围成的水库时,考虑非水平长铺盖渗漏影响的土坝渗流计算方法,并建立了库盘防渗优化的数学模型,以寻求坝高、坝长及防渗范围的最优组合方案。  相似文献   
6.
榆叶梅花粉贮藏及生活力的测定   总被引:3,自引:0,他引:3  
对不同品种的榆叶梅新鲜花粉及贮藏后花粉的生活力进行测定的结果表明:品种不同,花粉生活力及耐贮力均不相同,其中单辨品种的生活力和耐贮力最强。榆叶梅花粉最适萌发培养基成分为15%蔗糖 2%琼脂。花粉的适宜贮藏条件为0-4℃低温黑暗条件。  相似文献   
7.
[目的]克隆鉴定新疆天山亚种野生盘羊Toll样受体9(TLR9)基因,预测其结构与功能,并对序列进行分析。[方法]以外周血液的总DNA为模板,运用PCR方法分3段克隆了新疆野生盘羊TLR9基因,PCR产物经凝胶回收纯化后测序,并运用分子生物学软件将测序结果进行分析及结构预测。[结果]克隆得到的新疆野生盘羊TLR9基因大小是3192bp,含1个完整的开放阅读框(ORF),共编码1064个氨基酸,其氨基酸组成中亮氨酸的含量高达18.51%,含有30个氨基酸的信号肽序列;在野生盘羊TLR9蛋白455~475、740~760和780~800位氨基酸有3个跨膜区;新疆野生盘羊TLR9蛋白的3D结构是由胞外段富含亮氨酸的重复序列(LRR)和胞内段TIL(Toll/ILIR)结构域构成的。[结论]上述结构特征为TLR9发挥生物学功能奠定了基础,同时也为进一步研究新疆野生盘羊TLR9基因提供了理论依据。  相似文献   
8.
[Objective] Study on the genetic diversity in main cultivars of safflower distributing in Xinjiang Uighur Autonomous Region by means of RAPD makers.[Method] Genomic DNAs of 29 safflower accessions from Xinjiang Uighur Autonomous Region were extracted for PCR amplification using 20 RAPD primers.[Result] Totally 156 bands were amplified,among which 144 bands were polymorphic(accounting for 92.31%),indicating that safflower is endowed with plentiful genetic diversity.Based on the DNA fingerprint,the 29 safflower accessions were grouped into four populations,the classification results may be not related with ecological regionality.[Conclusion] RAPD technique is an available tool to analyze the genetic diversity of safflower germplasm at molecular level.  相似文献   
9.
[Objective] Study on the genetic diversities of A.splendens from different areas of xinjiang.[Method] The genetic diversities among seven populations and within two populations were analyzed by RAPD.[Result] Genetic clustering results presented that the relationships among populations of A.splendens are directly related with geographic positions,and within population are related with habitats.[Conclusion] RAPD technique can be used to study genetic diversity of A.splendens.  相似文献   
10.
本研究通过构建真核表达载体pEGFP-N3-vMIP-Ⅰ,电穿孔法将其转染至Jurkat细胞,荧光定量PCR检测vMIP-Ⅰ基因对Jurkat细胞内CCL5、APOBEC3G、APOBEC3F、等抗-HIV基因表达水平的影响,从而探讨vMIP-Ⅰ抗HIV感染的机制。结果显示:成功构建了pEGFP-N3-vMIP-Ⅰ载体,电穿孔转染效率达到40%左右,与转染空载体组相比,vMIP-Ⅰ转染组的Jurkat细胞内CCL5、A3G、A3F和MX1分别上调7.37倍、1.58倍、2.42倍和2.06倍。研究结果表明:vMIP-Ⅰ基因可激活Jurkat细胞内一些抗HIV相关基因的表达,这可能是vMIP-Ⅰ基因抗HIV感染的机制之一。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号