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151.
Muhammad Ashraf Sher Muhammad Shahzad Muhammad Imtiaz Muhammad Shahid Rizwan Muhammad Saleem Arif Rizwana Kausar 《Archives of Agronomy and Soil Science》2018,64(9):1181-1206
Relations between nitrogen (N) nutrition and salinity tolerance in plants are multifaceted and varies significantly depending on many soil and plant factors. Saline environment might experience an N dilemma due to the opposing effects of salt ions on N uptake, translocation and metabolism within the plant body. Adequate regulation of N under saline conditions can be a promising approach to alleviate salinity’s effects on plants by ameliorating ion toxicity and nutrient imbalances through its impacts on the uptake and redistribution of salt ions within the plant. Certain N-containing compounds including proline, glycine betaine, proteins and polyamines help the plants to tolerate salinity through their involvement in improving water uptake and water use efficiency, membrane integrity, enzyme activation, hormonal balance, chlorophyll synthesis, stimulation of photosystems and CO2 assimilation under salinity stress. Nitrogen, particularly NO3? represents a stress signal that triggers the activation of antioxidant enzymes to protect the plants against salinity-induced oxidative damage. Furthermore, the source/form of N application can affect not only N-interactions but also the behavior of other nutrients in stress environment. The present review deals with N-salinity relations in plants, particularly glycophytes, emphasizing on N-induced mechanisms which can improve plant adaptation to saline environment. 相似文献
152.
[目的]研究用基质固相分散法提取净化,离子色谱法测定卷烟中的糖和多元醇。[方法]将样品与石墨化碳黑球(w/w,1:4)充分研磨后装柱,用热水洗脱,洗脱液中的糖用离子色谱测定。以CarboPacMAl(4×250mm,5μm)阴离子交换柱为固定相,0.5mol/LNaOH溶液为流动相分离,脉冲安培检测器检测。[结果]一次进样可实现卷烟样品中甘油、丙二醇、木糖醇、山梨醇、葡萄糖、果糖、蔗糖、麦芽糖和半乳糖9种成分的同时测定。方法加标回收率在94.6%~105.7%,相对标准偏差小于3.0%,检测限均小于50μg/L.[结论]该方法重现性好,准确可靠,回收率较好,可用于实际烟草样品中糖和多元醇的测定。 相似文献
153.
154.
[目的]研究低浓度Mn2+、Cu2+或Zn2+营养液育苗对嫁接黄瓜叶片Mn、Cu和Zn含量,冷胁迫下SOD及其同工酶活性及电解质渗漏率的影响。[方法]用含有低浓度Mn2+、Cu2+或Zn2+营养液培育嫁接黄瓜幼苗,然后进行冷处理。[结果]降低营养液Mn2+、Cu2+或Zn2+浓度,嫁接黄瓜幼苗叶片SOD活性降低,电解质渗漏率增大,其中以Mn2+浓度降低对SOD活性和电解质渗漏率的影响最大,Cu2+次之,Zn2+影响最小。[结论]可以通过改变营养液中Mn2+、Cu2+或Zn2+含量进而改变黄瓜的抗冷性。 相似文献
155.
156.
PEG模拟干旱胁迫对不同黄瓜品种种子萌发的影响 总被引:5,自引:0,他引:5
以中农16号、津园6号、蔬春宝优26号黄瓜品种的种子为材料,采用不同浓度PEG6000(渗透势)模拟干旱胁迫,研究干旱胁迫对种子发芽率、发芽指数、活力指数、胚根长、下胚轴长、幼胚一级侧根数、电解质外渗率、胚根干质量的影响。结果表明,低渗透势对3个黄瓜品种的发芽率、发芽指数、活力指数、胚根长、下胚轴长、幼胚一级侧根数、胚根干质量有明显促进作用,高渗透势对上述指标有明显抑制作用,但电解质外渗率随渗透势的增加而降低。不同黄瓜品种抗旱性强弱依次为中农16号津园6号蔬春宝优26号。 相似文献
157.
158.
为了克服现有立式储罐检测方法的不足,提出一种可实现泄漏在线监控的新型双层罐底板结构方案,并搭建了一套基于PLC和相应传感器的试验系统.以93#汽油、柴油、水为泄漏介质,开展泄漏试验研究,验证了系统的可靠性和灵敏性.以93#汽油为例,研究了泄漏位置及泄漏量对泄漏扩散的影响规律.结果表明:对于相同的泄漏量,罐底中心处的泄漏扩散最快,可被检测到的时间最短,而边缘处可被检测到的时间相对更长;发生在同一位置的泄漏,其被测管路中泄漏介质体积分数值随泄漏量的增大而增大.试验结果表明:该系统具有足够的可靠性及灵敏性,可直接应用于双层罐底板结构立式储罐的现场监测. 相似文献
159.
《Communications in Soil Science and Plant Analysis》2012,43(15-20):2411-2422
Abstract A better understanding of nitrogen (N) availability to crops remains an essential key for a productive and safe production system. The main objective of this study was to evaluate the potential of anionic exchange membranes (AEMs) as part of a soil‐testing procedure to predict in situ soil NO3‐N availability for forage and corn produced in eastern Canada. The AEMs were buried in the surface horizon (0–15 cm) at four experimental sites for forage and at one site for corn. Treatments consisted of five NH4NO3 rates (0, 60, 120, 180, and 240 kg N ha?1) in forage and of six anhydrous ammonia (0, 50, 100, 150, 200, and 250 kg N ha?1) in corn production. In all sites, NO3 ? adsorbed on AEMs (NO3AEMs) increased significantly with N fertilizer rates, indicating the ability of the AEMs to detect differences between N fertilizer treatments and to predict the soil N availability to crops. The NO3AEMs fluxes were significantly related to soil NO3‐N concentration as extracted by water or KCl (0.66≤R2≤0.95). Significant relationships between crop N uptake and NO3AEMs were obtained (0.52≤R2≤0.94), suggesting that AEMs can be used as an index of soil N availability. Results indicated that AEMs provide a reasonably accurate evaluation of N availability to forage and corn. Because of their low cost, simplicity, and consistency over years, soils, and crops, AEMs could be efficiently used in soil N availability analysis. 相似文献
160.
《Communications in Soil Science and Plant Analysis》2012,43(8):823-835
Abstract Plant analyses methods have expanded immensely to document plant mineral element deficiency and toxicity disorders and to note mineral element interactions. Experiments were conducted to determine the feasibility of using cation exchange papers for the extraction of cationic elements from solutions to be analyzed by x‐ray fluorescence. The cationic elements Al, Fe, Mn, Zn, and Cu were effectively extracted from solutions by one exchange resin paper disk if solutions were passed several times through the exchange resin paper. Calcium and Mg were extracted from solutions if two or three separate exchange papers were used, and K was not extracted from solutions with the use of up to five separate exchange papers. The relatively high concentrations of K in solutions and the relatively low exchange capacity of ion exchange resin papers apparently prevented the effective removal of K from solution. The detectability limits on the exchange resin disks by this technique were <2.8 μg Al, 0.5 μg Fe, 0.10 μg Mn, 0.10 μg Zn, and 0.08 μg Cu. Extraction of cationic elements from solutions for x‐ray analysis appeared practical and relatively rapid for Al, Fe, Mn, Zn, and Cu, less practical for Ca and Mg, and impractical for K. 相似文献