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111.
为了解北京市猪伪狂犬病野毒感染情况,2017年从北京市7个区157个养猪场(户),采集5 469份猪血清样品,采用猪伪狂犬病病毒(PRV)gE抗体酶联免疫检测试剂盒进行血清学调查。结果显示:北京市7个区均有不同程度的PRV野毒感染,平均样品阳性率为53.36%。其中:经产母猪阳性率最高(58.28%),其次是育成猪(57.55%)、育肥猪(54.49%),后备母猪阳性率最低(37.46%);散养户的样品阳性率较高,为66.42%,规模猪场的阳性率较低,为47.71%。调查结果表明,北京市PRV野毒感染较为严重,对猪场采取伪狂犬病净化和综合防控措施势在必行。 相似文献
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The salt‐sensitive Glycine max N23674 cultivar, the salt‐born Glycine soja BB52 population, and their hybrid 4076 strain (F5) selected for salt tolerance generation by generation were used as the experimental materials in this study. First, the effects of NaCl stress on seed germination, tissue damage, and time‐course ionic absorption and transportation were compared. When qualitatively compared with seed germination appearance in culture dishes, and tissue damages on roots or leaves of seedlings, or quantitatively compared with the relative salt injury rate, the inhibition on N23674 was all the most remarkable. After the exposure of 140 mm NaCl for 1 h, 4 h, 8 h, 12 h, 2 days and 4 days, the content of Cl? gradually increased in the roots and leaves of seedlings of BB52, 4076 and 23674. Interestingly, the extents of the Cl? rise in roots of the three experimental soybean materials were BB52 > 4076 > N23674, whereas those in leaves were just on the contrary. Secondly, by using the scanning ion‐selective electrode technique (SIET), fluxes of Na+ and Cl? in roots and protoplasts isolated from roots and leaves were also investigated among the three experimental soybean materials. After 140 mm NaCl stress for 2, 4 and 6 days, and when compared with N23674, slighter net Cl? influxes were observed in root tissue and protoplasts of roots and leaves of BB52 and 4076 seedlings, especially at the cellular protoplast level. The results indicate that with regard to the ionic effect of NaCl stress, Cl? was the main determinant salt ion for salt tolerance in G. soja, G. max and their hybrid, and the difference in their Cl?/salt tolerance is mainly attributed to the capacity of Cl? restriction to the plant above‐ground parts such as leaves. 相似文献
114.
Xiao-Peng Lu Yong-Zhong Liu Gao-Feng Zhou Qing-Jiang Wei Hong-Ju Hu Shu-Ang Peng 《Scientia Horticulturae》2011
‘Yandangxueli’ is a pear cultivar with predominant citric acid in the ripe fruit, different from most of pear cultivars such as ‘Gengtouqing’ in which malic acid is the predominant acid type. It was found that ‘Yandangxueli’ accumulated citric acid for three times against that in ‘Gengtouqing’ at fruit ripening stage. To investigate the mechanism of citric acid accumulation in ‘Yandangxueli’, organic acids content, gene expression and enzyme activity were studied in both cultivars. Five genes, Pp:mtCs, Pp:cyAco, Pp:cyIdh, Pp:mtMdh and Pp:cyMe which encoded citric synthase (CS), cytosolic aconitase (cyACO), NADP-dependent isocitrate dehydrogenase (NADP-IDH), NAD-dependent malate dehydrogenase (NAD-MDH) and NADP-dependent malic enzyme (NADP-ME) respectively, were identified from pear fruit. Their expression profiles and the corresponding enzyme activities were determined throughout fruit development in both cultivars. Results from these enzymes indicated that there were no strict relationship between gene expression, enzyme activity and citric acid accumulation. Expression analysis for two Py:vVAtp genes encoding vacuolar H+-ATPase A subunit and one Py:vVpp gene encoding Vacuolar H+-pyrophosphatase showed that they were all with up-regulated expression at the later development stage of ‘Yandangxueli’ but with down-regulated expression in ‘Gengtouqing’. Therefore, it is concluded that the different ability in citric acid transportation and storage might be involved in the high citric acid content in ‘Yandangxueli’. 相似文献
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116.
为探明拔节期氮肥运筹对不同滴灌量下冬小麦光合特性及产量的影响,在大田滴灌技术条件下,以‘新冬41号’为试验材料,研究4种拔节期氮肥运筹处理[N0(0 kg/hm2)、N1(90 kg/hm2)、N2(180 kg/hm2)、N3(270 kg/hm2)]对3种不同滴灌量[W1(1500 m3/hm2)、W2(3000 m3/hm2)、W3(3450 m3/hm2)]下冬小麦叶绿素含量(SPAD值)、叶面积指数(LAI)、叶片光合特性及产量的影响。结果表明,在3种滴灌量下各氮肥处理冬小麦拔节至乳熟期叶片SPAD值均呈“先增后降”的变化规律,最大值均在灌浆期;LAI呈现“先增后降”的变化规律,在孕穗期达最大。在同一施氮水平下,滴灌量增加,叶片的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均增加,而胞间CO2浓度(Ci)则降低。滴灌量较低时(W1处理),增加拔节期施氮量能有效提高滴灌冬小麦的有效穗数、穗粒数、千粒重、产量和收获系数;水分充足时(W2、W3处理),增加拔节期施氮量反而不利于产量的提高。综合考虑各项产量指标及氮肥利用效率得出,在滴灌量3000 m3/hm2条件下,拔节期施氮量180 kg/hm2时,滴灌冬小麦籽粒产量较高,氮肥利用率最大,可供生产参考。 相似文献
117.
保护教育作为现代动物园的主要职能之一,常态化的保护教育项目的开展正是动物园这一职能的重要体现.近两年南京市红山森林动物园开发了6个动物场馆幕后之旅的常态化教育项目,以澳洲区幕后之旅为例,通过对2014年4~7月的活动参与者进行问卷调查,对教育项目进行评估.结果显示此类教育项目切合当下亲子游的市场需求,对于影响常态化教育项目初期的正常开展的主要因素有市场推广、项目内容和师资力量.其中市场推广效果较好的是朋友推荐和网络宣传;项目内容中受欢迎程度较高的是亲近动物或动物相关内容;关于项目形式幼儿(4~6岁)偏好游戏互动环节而小学低年级(7~9岁)偏好动物故事环节. 相似文献
118.
D. Liu Z. F. Pei M. S. Naeem D. F. Ming H. B. Liu F. Khan W. J. Zhou 《Journal of Agronomy and Crop Science》2011,197(4):284-295
The present study assesses the effects of 5‐aminolevulinic acid (ALA, 0, 0.1, 1 and 10 mg l?1) on the growth of oilseed rape (Brassica napus L. cv. ZS758) seedlings under water‐deficit stress induced by polyethylene glycol (PEG 6000, 0 and ?0.3 MPa). Water‐deficit stress imposed negative effects on seedling growth by reducing shoot biomass, cotyledon water potential, chlorophyll content and non‐enzymatic antioxidants (glutathione and ascorbic acid) levels. On the other hand, water‐deficit stress enhanced the malondialdehyde (MDA) content, reactive oxygen species (ROS) production, enzymatic antioxidants activities, reduced/oxidized glutathione ratio (GSH/GSSG) and reduced/oxidized ascorbic acid (ASA/DHA) ratio in seedlings. Application of ALA at lower dosages (0.1 and 1 mg l?1) improved shoot weight and chlorophyll contents, and decreased MDA in rape seedlings, whereas moderately higher dosage of ALA (10 mg l?1) hampered the growth. The study also indicated that 1 mg l?1 ALA improved chlorophyll content, but reduced MDA content and ROS production significantly under water‐deficit stress. Lower dosages of ALA (0.1 and 1 mg l?1) also enhanced GSH/GSSG and ASA/DHA as compared to the seedlings under water‐deficit stress. The antioxidant enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase and superoxide dismutase) enhanced their activities remarkably with 1 mg l?1 ALA treatment under water‐deficit stress. It was also revealed that 1 mg l?1 ALA treatment alone induced the expression of APX, CAT and GR substantially and under water‐deficit stress conditions ALA treatment could induce the expression of POD, CAT and GR to a certain degree. These results indicated that 0.1–1 mg l?1 ALA could enhance the water‐deficit stress tolerance of oilseed seedlings through improving the biomass accumulation, maintaining a relative high ratio of GSH/GSSG and ASA/DHA, enhancing the activities of the specific antioxidant enzymes and inducing the expression of the specific antioxidant enzyme genes. 相似文献
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120.
FGF4已经被证明是癌基因,它涉及肿瘤的生长和转移,为了解FGF4的表达与肿瘤微环境的关系。我们利用FGF4抗体通过免疫组化对一名肺癌患者癌旁,癌组织,癌组织小鼠移植瘤,二次移植瘤以及原代培养的细胞爬片进行FGF4检测,探究其表达差异。通过对比癌组织与对照组(癌旁组织),FGF4在癌巢中高表达;同样,移植瘤与二次移植瘤的癌巢中与癌旁组织比较,FGF4表达相对较高;但是将癌组织进行原代培养后,免疫组化检测细胞爬片FGF4,发现仅有5%±0.21%的肿瘤细胞表达FGF4,对照蛋白Cytokine作为肿瘤标记物,则在100%的肿瘤细胞中表达。研究提示免疫组化检测到FGF4在体内和体外表达不同,提示肿瘤细胞FGF4的表达与肿瘤微环境调控密切相关,肿瘤微环境对肿瘤细胞的FGF4的调控有着重要作用。 相似文献