外源乙烯对黄瓜幼苗根系生长及内源多胺含量的影响   总被引：4，自引：0，他引：4  

汪天  王素平  郭世荣 《沈阳农业大学学报》2006,37(3):473-475

精确控制营养液溶氧浓度和外源乙烯浓度,研究了黄瓜幼苗根系在低氧水培时的生长情况以及PAs含量的变化。结果表明,外源乙烯对根际低氧逆境下黄瓜幼苗根系的生长有抑制作用,虽然根径增粗,含水量增加,但根系的总根数、总表面积、总体积、干重和鲜重都有所减少,随着乙烯浓度的增加,抑制作用增强;外源乙烯对根际低氧逆境下黄瓜幼苗根系PAs含量有着明显的拮抗作用,外源乙烯使根际低氧逆境下黄瓜幼苗根系的伤害症状加重。  相似文献   

水分胁迫对三桠生理特性的影响   总被引：4，自引：0，他引：4  

徐小牛 《安徽农业大学学报》1995,22(1):42-47

研究了盆栽三桠在人工控制土壤水分条件下某些生理特性的变化。结果表明,在土壤干旱条件下,三桠叶片自由水锐减,而束缚水含量有所增加,叶绿素含量及净光合速率随着土壤干旱的加重而下降,呼吸消耗增加,光合作用效率降低,蒸腾速率明显下降,在重度干旱时下降达６６．６％,水分利用效率有所提高,游离脯氨酸积累较少。这说明三桠对水分胁迫的适应能力较差。  相似文献   

呼吸阀的工作特性和新型呼吸阀的开发   总被引：4，自引：0，他引：4  

张丽娜  陈保东  王立志 《油气储运》2001,20(11):46-48

介绍了呼吸阀的设计和工作特性，分析了冬季使用呼吸阀容易冻结的原因，基于热管的工作原理，提出了采用热管呼吸阀解决呼吸阀的冻结问题，针对呼吸阀现场检测困难等问题，指出开发并使用智能呼吸阀是解决该问题的有效方法。  相似文献   

热处理结合茎尖培养去除甘薯丛枝病植原体     

兰平  李文凤  朱水芳 《西北农林科技大学学报(自然科学版)》2001,29(3):1-4

以甘薯丛枝病试管苗病株为材料，用热处理结合茎尖培养法对甘薯丛枝病病株进行了去除植原体 的研究。结果表明，０． ５ ｍｍ以下茎尖培养可以去除植原体，茎尖越小，去除植原体的效果越好，但成苗率降低； ０．８ ｍｍ以上茎尖培养不能去除植原体，但是成苗率较高。（３９±１）℃高温连续处理２～３周后，剥取茎尖培养可以 提高去除植原体的效率，对成苗率影响不大，热处理时间越长，去除植原体效果越好，但被处理的试管苗易死亡。甘 薯丛枝病试管苗在（３９±１）℃高温下，以处理３周为宜。  相似文献   

酸枣仁散对运输应激大鼠脑内5-HT表达的影响     

王利利  马彤辉  俞明远  汤林杰  张文君  许剑琴  刘风华  马云飞  滕可导 《中国农业大学学报》2015,20(4):152-157

为研究运输应激对脑内五羟色胺(5-hydroxytryptamine,5-HT)表达的影响及酸枣仁散对运输应激的调控作用,试验采用摇床模拟公路运输途中的摇晃、高温和拥挤等因素,建立大鼠运输应激模型(35℃,60r/min,每天应激2h,连续7d)。将40只大鼠随机分为对照组、酸枣仁组、应激组和应激+酸枣仁组,分别处理7d后,断头取脑,利用酶联免疫吸附法(ELISA)和免疫组化法检测各组大鼠脑区5-HT含量变化及分布。酶联免疫吸附法检测结果显示,与对照组相比,应激组大鼠中缝核、海马和纹状体等脑区5-HT表达量均明显减少(P0.05),应激+酸枣仁组较应激组5-HT表达量显著增加(P0.05)。免疫组化结果显示,在中缝背核及其亚核DRDsh、DRv和DRc亚核,应激组大鼠5-HT灰度值与对照组相比显著下降(P0.05),应激+酸枣仁组与应激组相比显著上升(P0.05)。以上结果表明,运输应激可以导致中枢神经系统部分脑区5-HT含量下降,而酸枣仁散可能通过上调脑内5-HT的含量来调控运输应激。  相似文献   

非饱和黄土中的吸力与有效应力     

李靖  党进谦  刘祖典 《西北农林科技大学学报(自然科学版)》1997,25(4):23-27

用压力板法和回归分析法研究了基质吸力对非饱和黄土强度性质的影响。结果表明，非饱和黄土的基质吸力与饱和度在双对数座标上呈直线关系；起始基质吸力与液限、塑性指数及粘粒含量呈线性规律变化；有效应力影响系数与其起始基质吸力呈线性关系，且随粘粒含量的增大而增大。  相似文献   

Effects of polyamines on K+, Na+ and Cl− content and distribution in different organs of cucumber (Cucumis sativus L.) seedlings under NaCl stress     

Suping Wang  Yongxia Jia  Shirong Guo  Guoxian Zhou 《Frontiers of Agriculture in China》2007,1(4):430-437

Seedlings from the salt-sensitive cucumber cultivar Jinchun No. 2 and the salt-tolerant cucumber cultivar Changchun Mici were exposed for 8 days to 50 mmol/L NaCl in the absence or in the presence of exogenous foliar spraying PAs [putrescine (Put), spermidine (Spd), and spermine (Spm) 1 mmol/L] to compare the effects of different kinds of polyamines (PAs) on plant tolerance to salinity. This paper studied the effects of exogenous PAs on K⁺, Na⁺ and Cl⁻ in different organs of cucumber seedlings. The results showed that K⁺ content as well as the ratios of K/Na and Cl/Na decreased, while Na⁺ and Cl⁻ concentrations increased in salt-treated cucumber seedlings. The differences in K⁺, Na⁺ and Cl⁻ content and the K/Na and Cl/Na ratios were greater for the salt sensitive cultivar Jinchun No. 2 than for the salt-tolerant cultivar Changchun Mici. Cucumber seedlings treated with exogenous polyamines and combined with salinity exhibited a higher level of K⁺ accumulation and lower levels of Na⁺ and Cl⁻ accumulation compared with the seedlings treated only with salt stress. Among the three kinds of polyamines, Spd and Spm were more effective in inhibiting the accumulation of Na⁺ and reduction of K⁺. However, Put was more effective in reducing Cl⁻ accumulation. Furthermore, all of the three kinds of exogenous polyamines could increase the ratio of K/Na, improving the absorption and transport selectivities of K⁺ and Na⁺ from stems to leaves for both cultivars. In conclusion, exogenous polyamines could alleviate salt damage to some extent and enhance the accumulation of biomass. Among the three kinds of polyamines, spermidine was most effective. Exogenous polyamines could improve tolerance of cucumber seedlings under salt stress by regulating the absorption and distribution of ions in different organs. __________ Translated from Acta Ecologica Sinica, 2007, 27(3): 1122–1129 [译自: 生态学报]  相似文献   

减轻产蛋鸡热应激的综合措施   总被引：1，自引：0，他引：1  

丁馥香 《山西农业科学》2002,30(2):73-75

在高温季节 ,对不同建筑类型的鸡舍及不同管理条件的鸡群 ,通过改善通风条件、减少辐射、调整饲料的营养水平、增加营养素、改善饲养管理等综合技术措施 ,达到减轻产蛋鸡热应激的目的 ,使产蛋鸡在炎热气候条件下也能正常生产。  相似文献   

Paraquat Resistance in Leaf Discs of PAAG12-IPTModified Gerbera Is Related to the Activities of Superoxide Dismutase, Catalase, and Dehydroascorbate Reductase     

LAI Qi-xian BAO Zhi-yi ZHU Zhu-jun MAO Bi-zeng QIAN Qiong-qiu 《中国农业科学(英文版)》2007,6(4):446-451

In this paper, using in vitro leaf disc culture system, the changes of contents of chlorophylls, carotenoids, soluble protein, thiobarbituric acid reactive substance （TBARS）, and activities of antioxidant enzymes were investigated during the incubation of leaf discs of PSAG12-IPT modified gerbera in 0, 25, 50 μmol L^-1 paraquat （PQ） under continuous light intensity of 130 0tool m-2 s-1, compared with the control plant （wild type）. The results showed that PQ treatment significantly decreased the contents of chlorophylls, carotenoids, and soluble protein, therefore, promoted leaf senescence. However, the decreases in the leaf discs of modified gerbera were considerably smaller. The activities of superoxide dismutase （SOD）, catalase （CAT）, and dehydroascorbate reductase （DHAR） were significantly increased by PQ treatment and with the increasing of PQ concentration, particularly in the modified plants. The activities of ascorbate peroxidase （APX） and guaiacol peroxidase （GPX） could not be detected in the leaf discs of PQ treatments, which suggested that they were labile to the oxidative stress induced by PQ. As a product of lipid peroxidation, TBARS significantly increased in content with the increase of PQ concentration, while its concentration in the modified plants was significantly lower than that of control plants. Therefore, it could be concluded that the chimeric gene PSAG12-IPTtransfonnexi gerbera leaves had higher antioxidative potential, thus causing the delay of senescence under oxidative stress induced by PQ.  相似文献   

稗草和水分胁迫对大豆地上器官氮素分配与积累的交互影响     

由振国 《中国农业大学学报》1995,(4):383-388

稗草生长明显降低了大豆籽粒蛋白质产量及氮素向其籽粒中的分配比例,但显著提高了大豆茎、叶、籽含氮量及氮素向其茎、叶中的分配比例。这种影响在座荚期渍涝和鼓粒期干旱条件下最为突出;稗草对大豆粒蛋白质生产的危害在幼苗期一开花期的渍涝条件下显著减轻,而在任一时期的干旱条件下均明显加重,且在座荚期的渍涝处理中比在幼苗期一开花期的溃涝处理中大。不同时期、不同旱涝胁迫处理对大豆籽粒蛋白质产量的降低程度不同,其中旱害远大于涝害,后期旱害大于前期旱害,先涝后旱的危害大于先旱后涝的危害;开花期大豆最不耐涝,鼓粒期最不耐旱。  相似文献