A comparative survey of recent results on humic-like fractions in organic amendments and effects on native soil humic substances     

Nicola Senesi  César Plaza  Alfredo Polo 《Soil biology & biochemistry》2007,39(6):1244-1262

The main scope of the wide use of organic amendments of various origin and nature in modern agriculture is to increase and/or restore the organic matter content in organically poor or depleted soils in order to maintain and/or increase crop production and reduce soil exposure to degradation, erosion, desertification and pollution. The agronomically efficient and environmentally safe use of any organic amendment requires, however, an adequate control not only of the chemical quality of the humic substance (HS)-like fractions contained, which is an important indicator of the maturity and stability achieved by organic matter in the amendment, but also of the effects that these HS may have on native soil HS. In this review, the most recent results obtained on this topic by the research groups operating in Bari, Italy, and in Madrid, Spain, are discussed comparatively with results recently published by other research groups. Overall, HS-like components of organic amendments are characterized by higher aliphatic character and molecular heterogeneity, lower contents of O, acidic functional groups and organic free radicals, and lower degrees of aromatic ring polycondensation, polymerization and humification than native soil HS. These differences are less evident for composted materials. The composition, structure and functionalities of HS in amended soils may be affected in different ways and at various extents on dependence of the nature, origin and rate of amendment. In general, these properties are intermediate between those of the unamended soil HS and the HS-like fractions in the amendment, but generally resemble more the former than the latter, especially with increasing time after amendment application.  相似文献   

Effects of organic manure on nitrification in arable soils     

H. J. Laanbroek  S. Gerards 《Biology and Fertility of Soils》1991,12(2):147-153

Summary The production of nitrate by the process of nitrification is highly dependent on other N-transforming processes in the soil. Hence, changes in the type of N compound applied to enrich agricultural soils may affect the production of nitrate. The size and activity of the chemolithotrophic bacterial community were studied in an integrated farming system, with increased inputs of organic manure and reduced inputs of mineral nitrogenous fertilizer, versus conventional farming. The integrated farming had a positive effect on potential nitrifying activity, but not on the numbers of chemolithotrophic nitrifying bacteria as determined by a most probable number technique or by fluorescence antibody microscopy. Cells of the recently described nitrite-oxidizing species Nitrobacter hamburgensis and Nitrobacter vulgaris were just as common as the cells of the well known species Nitrobacter winogradskyi. It was concluded that nitrification is stimulated by integrated farming, presumably by an increased mineralization of ammonium which is not immediately consumed by the crop or immobilized in the heterotrophic microflora of the soil. Since nitrifying bacteria are involved in the production of NO and N₂O, integrated farming with the application of manure may favour the production of noxious N-oxides.Communication no. 40 of the Dutch Programme on Soil Ecology of Arable Farming Systems  相似文献   

低磷胁迫对小麦代换系荧光参数的影响及染色体效应     

郑金凤  白志英  李存东 《华北农学报》2013,(4)

以中国春-Synthetic 6x染色体代换系及其亲本为材料,通过测定不同磷处理条件下孕穗期、开花期、灌浆期旗叶的荧光参数,研究低磷胁迫对荧光参数的影响,并对控制荧光参数的相关基因进行染色体定位。结果表明,低磷胁迫导致小麦代换系及其亲本的最大荧光（ Fm）、PSⅡ原初光能转换效率（ Fv/Fm）在测定的各生育时期中明显低于对照,初始荧光（Fo）明显高于对照;Synthetic 6x的3D染色体上可能存在低磷胁迫下调控Fo的有利基因;3B染色体上可能存在调控Fm的有利基因;3B、7D染色体上可能存在调控Fv/Fm的有利基因。  相似文献   

NaCl胁迫对番茄嫁接苗光合作用和叶绿素荧光特性的影响     

李汉美  何勇 《西北农业学报》2013,22(3):131-134

采用水培的方法,以野生番茄为砧木,栽培番茄为接穗进行嫁接,从番茄叶片的光合特性和叶绿素荧光特性两方面研究嫁接对100 mmol·L^-1 NaCl胁迫下番茄幼苗的影响。结果表明,NaCl胁迫下,番茄自根苗的净光合速率和蒸腾速率下降,嫁接苗受影响较小。盐胁迫下,自根苗的Φ_PSⅡ和Fv/Fm下降,NPQ显著上升,而嫁接苗受盐害影响不明显。因此说明,盐害引起的渗透胁迫主要因为非气孔限制,嫁接提高番茄的光合速率和水分利用效率,有利于番茄对光能的捕获和转化,减少电子传递过程中以热能耗散的光能,降低盐胁迫对番茄生长的抑制作用,促进番茄植株生长。  相似文献   

Sexing of Dog Sperm by Fluorescence In Situ Hybridization     

Maya OI  Keisuke YAMADA  Hiroyuki HAYAKAWA  Hiroshi SUZUKI 《The Journal of reproduction and development》2013,59(1):92-96

Effective preselection of sex has been accomplished in several species of livestock and also in humans using the flow cytometric sperm sorting method. A guaranteed high sorting accuracy is a key prerequisite for the widespread use of sperm sexing. The standard validation method is flow cytometric remeasurement of the DNA content of the sexed sperm. Since this method relies on the same instrument that produced the original sperm separation, it is not truly independent. Therefore, to be able to specifically produce either male or female offspring in the dog, we developed a method of direct visualization of sex chromosomes in a single sperm using fluorescence in situ hybridization (FISH) as a validation method. Denaturation of canine spermatozoa by immersion in 1 M NaOH for 4 min yielded consistent hybridization results with over 97% hybridization efficiency and a good preservation of sperm morphology. There was no significant difference between the theoretical ratio (50:50) and the observed ratio of X- and Y-chromosome-bearing spermatozoa in any of the three dogs. In addition, the mean purities of flow-sorted sex chromosomes in spermatozoa of the three dogs were 90.8% for the X chromosome fraction and 89.6% for the Y chromosome fraction. This sorting was evaluated by using the dual color FISH protocol. Therefore, our results demonstrated that the FISH protocol worked reliably for both unsorted and sexed sperm samples.  相似文献   

应用2D-DIGE技术分析柑橘衰退病毒诱导的甜橙差异表达蛋白     

杨方云  李中安  周常勇  周彦 《果树学报》2013,(1):16-21,182

【目的】为了研究柑橘衰退病毒(Citrus tristeza virus,CTV)诱导甜橙差异表达蛋白的分离和鉴定,【方法】以接种了CTV的甜橙植株为实验组,健康植株为对照组,利用双向荧光差异凝胶电泳(2D-DIGE)技术分析CTV诱导的甜橙差异表达蛋白。【结果】以t检验P<0.05和相对表达量≥1.5的水平作为判别标准,获得了91个CTV诱导的差异表达蛋白点,在实验组中含量高于对照组的蛋白56个,含量低于对照组的蛋白35个。通过MALDI-TOF质谱分析成功鉴定从中选择的37个蛋白点,其中19个蛋白功能明确,16个为预测或假定具有某种蛋白功能,包括与抗氧化相关的硫氧还蛋白、铁氧还蛋白、超氧化物歧化酶和抗坏血酸过氧化酶,与代谢相关的磷酸甘油酸酯水解酶、木葡聚糖内糖基转移酶、变味蛋白,分子伴侣热激蛋白,折叠酶肽酰脯氨酰顺反式异构酶,以及与光合代谢相关的蛋白等。【结论】CTV的侵染影响到甜橙各种复杂的生物学过程。  相似文献   

燕麦属植物核糖体DNA染色体定位及45S rDNA的系统进化分析     

王炳策  刘晓娟  程斌  任明见  徐如宏  张素勤  张立异  何方 《作物杂志》2021,37(4):10-8

由于缺乏明确的二倍体供体信息,燕麦属植物的起源和系统进化关系一直存在争议。利用荧光原位杂交（fluorescence in situ hybridization,FISH）方法,检测45S rDNA和5S rDNA在燕麦属不同倍性植物染色体上的位点信息;并依据已公开的45S rDNA ITS区全长DNA序列构建分子进化树。探讨燕麦属植物在不同基因组中45S rDNA的位点变化、进化规律以及分化机制,为探究燕麦属物种的起源与演化提供参考。  相似文献   

新疆红花随体染色体及25S rDNA位点分析     

王力军  严兴初 《中国油料作物学报》2012,34(3):245-248

利用荧光原位杂交技术研究我国新疆红花25S rDNA在染色体上的位点数目,同时分析了其随体染色体数目。研究结果显示：新疆红花有2对随体染色体;4对染色体存在25S rDNA位点,其中3对染色体上的杂交信号较强,可稳定检出,有时还可检测到1对染色体上较弱的杂交信号。与国外红花品种相比,新疆红花rDNA位点数目多,表明新疆红花与国外红花品种间核仁组织区结构存在较大差异。这些结果将为研究红花染色体进化及其准确的核型分析提供一定的参考。  相似文献   

有机磷农药敌敌畏和乐果在大白菜表面半衰期的研究     

王清路  张玉军  李俏俏 《安徽农业科学》2011,39(27):16640+16643-16640,16643

[目的]了解有机磷农药敌敌畏和乐果在大白菜叶面的动态残留情况。[方法]对敌敌畏和乐果的荧光光谱特征进行了分析,并利用荧光光谱法测定了大白菜叶面敌敌畏和乐果的半衰期。[结果]敌敌畏和乐果均以280 nm波长光线激发时,敌敌畏的发射峰在328nm处,而乐果在574 nm处。大白菜叶面敌敌畏的半衰期约为48 h,而乐果约为72 h。[结论]为蔬菜上的农药残留检测提供了参考。  相似文献   

家榆和金叶榆光合·蒸腾及荧光参数对水分胁迫的响应   总被引：1，自引：1，他引：0  

曹书敏  杨晴  杨俊明  李搬顺  黄印冉  张均营 《安徽农业科学》2011,39(22):13477-13480

[目的]探讨家榆和金叶榆抗旱能力的差异。[方法]设置4个土壤水分梯度,用2年生家榆和金叶榆幼苗进行盆栽控水试验,利用GFS-3000便携式光合作用荧光测量系统测定试验苗的光合、蒸腾和荧光参数。[结果]随水分胁迫程度的加剧,家榆和金叶榆光合速率、蒸腾速率、水分利用效率、气孔导度均呈下降趋势;水分胁迫程度越高,金叶榆光合速率比家榆下降的幅度越小;在重度水分胁迫条件下,金叶榆的蒸腾速率、非光化学猝灭明显低于家榆,叶片气孔导度、叶绿素荧光参数光化学猝灭则明显高于家榆。[结论]在干旱条件下,金叶榆的抗干旱能力、自我调节能力、适应环境的能力较家榆更强,适应重度干旱环境的潜力更大。  相似文献