渍害胁迫下小麦生长的响应机理及调控措施研究进展

全球气候变化导致近年来渍害频发,而旱地作物小麦对渍害敏感。受气候、土壤、轮作制度等因素的影响,我国长江中下游小麦主产区的渍害灾情严重。渍害引起的土壤溶氧量降低可以导致小麦根系生长受到抑制,进而限制植株生长,最终降低小麦产量和品质。本文基于国内外相关研究,从根系呼吸代谢、水分传导、矿质养分吸收、光合作用、氧化还原代谢等方面概述了渍害胁迫抑制小麦生长的生理机理;讨论了小麦通过无氧呼吸维持能量供应和改变根系形态维持氧气供应等渍害适应机制;总结了肥料调控、生长调节剂调控和胁迫记忆等栽培措施在小麦抗渍上的应用及其机理,并对未来小麦抗渍研究进行了展望,以期为小麦的耐渍栽培和稳产高产管理提供理论支撑。     

Short-term homeostatic regulation of blood/interstitial fluid Ca2+ concentration by the scales of anadromous sea trout Salmo trutta L. during smoltification and migration

The elasmoid scales of anadromous sea trout Salmo trutta L. represent a significant internal reservoir of Ca²⁺. Although more is known about long-term remodelling of scales in response to calciotropic challenges encountered during smoltification and migration, very little is known about the contribution made by scales to the short-term, minute-to-minute regulation of Ca²⁺ homeostasis in the extracellular fluid (ECF) during these phases of the life cycle. This gap in the knowledge is partly due to the technical challenges involved in measuring small Ca²⁺ fluxes around the scales of live fish in real time. Here, this study describes exfoliating, mounting and culturing scales and their resident cells from parr, smolt and adult sea trout from a freshwater environment, as well as from adult sea trout caught in sea or brackish water. All the scales were then examined using an extracellular, non-invasive, surface-scanning Ca²⁺-sensitive microelectrode. The authors quantified the Ca²⁺ fluxes, in the absence of any systemic or local regulators, into and out of scales on both the episquamal and hyposquamal sides under different extracellular calcemic challenges set to mimic a variety of ECF-Ca²⁺ concentrations. Scales from the life-cycle stages as well as from adult fish taken from sea, brackish or fresh water all showed a consistent efflux or influx of Ca²⁺ under hypo- or hypercalcemic conditions, respectively. What were considered to be isocalcemic conditions resulted in minimal flux of Ca²⁺ in either direction, or in the case of adult scales, a consistent but small influx. Indeed, adult scales appeared to display the largest flux densities in either direction. These new data extend the current understanding of the role played by fish scales in the short-term, minute-to-minute homeostatic regulation of ECF-Ca²⁺ concentration, and are similar to those recently reported from zebrafish Danio rerio scales. This suggests that this short-term regulatory response might be a common feature of teleost scales.     

Study of Spectral Response Characteristics of Oilseed Rape (<i>Brassica napus</i>) to Particulate Matters Based on Hyper-Spectral Technique

Haze is mainly caused by the suspended particulate matters in the air, of which the particulate matters pollution harms leaf vegetables. In this paper, oilseed rapes at four different growing periods were investigated in a simulated particulate pollution environment. In combination of hyper-spectral technology and micro examination, the response of hyper-spectral characteristics of the leaf to particulate matters was investigated in-depth. The hyperspectral, chlorophyll content, net photosynthetic rate and stomatal conductance of leaf were obtained. The deposition and adsorption of particulate matters on the leaf were observed by Environmental Scanning Electron Microscope (ESEM). Normalized difference vegetation index (NDVI), modified red edge normalized (mNDVI705) and modified red edge simple ratio index (mSR705) were selected as characteristic parameters and the range of 510 nm~620 nm as the sensitive band. 16 methods were used to establish the physiological information inversion model. The main results were as follows: Under the influence of particulate matters, the spectral reflectance decreased as a whole. With the increase of leaf age, the phenomenon of blue shift aggravated. The amplitude of yellow and blue edge decreased with overall decreasing vegetation indices. The furrows and irregular band protrusions in leaves were favorable for keeping particulate matters. With longer affecting time and more deposition of particle matters on the leaf, the stomatal opening became smaller. After comparing, principal component regression (PCR) + multiple scatter correction (MSC) + second derivative (SD) + Savitzky-Golay smooth (SG), and partial least square (PLS) + multiple scatter correction (MSC) + first derivative (FD) + Savitzky-Golay smooth (SG) were determined the best method to establish the inversion model of chlorophyll content and net photosynthetic rate respectively. This study may bring novel ideas for the diagnosis and analysis of the physiological response of leaf vegetables under particulate matters pollution using hyper-spectral technology.     

Antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases and finding out new strain of Serratia marcescens via DGGE-PCR,as a secondary infection on honeybee larvae

American foulbrood (AFB) and European foulbrood (EFB) are the two major bacterial diseases affecting honeybees, leading to a decrease in viability of the hive, decreasing honey production, and resulting in significant economic losses to beekeepers. Due to the inefficiency and/or low efficacy of some antibiotics, researches with nanotechnology represent, possibly, new therapeutic strategies. Nanostructure drugs have presented some advantagesover the conventional medicines, such as slow, gradual and controlled release, increased bioavailability, and reduced side-effects. In this study, different infected larvae were collected from two apiaries; the combs that had symptoms of American and European foulbrood were isolated. In vitro antimicrobial activity of camphor tree silver nano-particles against foulbrood diseases were characterized using UV–Vis spectrophotometry and scanning electron microscope (SEM) that proves the formation of silver nanoparticles with size range 160–660 nm. The antimicrobial activity of the silver nanoparticles was tested using agar diffusion assay and proved their ability to effectively cease the pathogenic bacterial growth in both AFB and EFB. DGGE-PCR technique has been applied for the identification of un-common bacterial infections honeybees depending on 16S rRNA amplification from their total extracted DNA and has been identified as Serratia marcescens (TES), deposited in GenBank with a new accession number (MT240613). The results were confirmed strain has been detected by DGGE-PCR analysis causing uniquely infected brood that was attacked by the American Foulbrood It could be concluded that greenly synthesized silver nanoparticles is projected to be used as effective treatment for honeybee bacterial diseases. These material need more investigations under field conditions and study the possibility of its residues in honeybee products such as honey, and beeswax.     

Luminescence properties of Tb3+ doped Sr2SnO4 green phosphor in UV/VUV regions

Polycrystalline Sr₂SnO₄ phosphors doped with Tb³⁺ were prepared by conventional solid‐state reaction method. Materials were characterized by powder XRD and EDS techniques. The luminescence properties of these materials were investigated under UV and VUV excitation. Upon excitation at 272 nm, phosphors exhibited intense emissions at 492 and 543 nm due to ⁵D₄ → ⁷ F₆ and ⁵D₄ → ⁷ F₅ transitions of Tb³⁺ ions, respectively. Materials also exhibited strong emissions from these transitions under VUV excitation at 147, 173 and 230 nm. Quantitative analysis of the spectra indicated probable applications of these phosphors for PDP and other display devices as green emitting phosphors. Copyright © 2012 John Wiley & Sons, Ltd.     

两种手术方式对慢性中耳炎听力改善的临床分析

目的：研究慢性中耳炎患者术后听力改善及其可能相关影响因素。方法：随访自2010年3月至2012年5月于本院耳鼻喉科进行慢性中耳炎手术的患者,将随访资料的病例行回顾性分析。结果：84例置入PORP病例术后气导听阈平均39．6±14．9dB,较术前,提高平均为13．9±13．2dB（P〈0．001）;平均气骨导差为20．5±8．5dB,气骨导差改变平均为8．8±10．7dB（P〈0．001）。术后气导听阈改善在0．5KHz,1KHz,2KHz三个频率上无明显差异（P〉0．05）,而气骨导差改善显示2KHz的改善不及0．5KHz,1KHz的气骨导差改善（（P〈0．001）。6例行颞肌筋膜鼓膜成型术病例术后气导听阈平均21．1±4.3dB,较之术前提高平均为13．6±7．2dB（P〈0．05）,平均气骨导差为11．1±4．2dB,气骨导差改变平均为6．7±4．2dB（P〈0．05）。结论：置入PORP、颞肌筋膜鼓膜成型术均可明显改善听力。慢性中耳炎手术治疗效果令人满意,羟基磷灰石假体听骨对于听力改善效果肯定。     

Untersuchungen über die Druckammonisierung von kohlenhydrathaltigen Futterstoffen

Chopped wheat straw was homogeneously mixed with urine of horses (5.75 gN per 1, 16.88 atom‐% ¹⁵N‐excess) and airtightly stored in plastic containers for 6 months. Three rumen fistulated sheep and goats each were fed with untreated or urine treated straw. Concentrate was added to straw. Untreated and urine treated straw were given in nylon bags and incubated in the rumen of sheep and goats for 1, 3, 6, 12, 24, 48 and 72 hours. A three compartment exponential function was used to fit the measurements of ¹⁵N‐ex‐cess and ¹⁵N‐amount of bag content. The curves and the calculated partial Y‐values of the three compartments show the inflow and outflow of ¹⁵N into or from the bags and allow conclusions about the binding of urine N. Most N of urine was not compactly bound by straw during storage. Primarily micro‐bial N was attached to the straw in the rumen. About 6% of urine N were bound more compact to the straw. Similar curves were calculated for ¹⁵N‐excess and ¹⁵N‐amount of nylon bags. The curves allow conclusions about tracer flows without quantitative knowledge. There were no significant differences between animal species.     

Homogenization of Pseudomonas aeruginosa PAO1 biofilms visualized by freeze‐substitution electron microscopy

A knowledge of the mechanical properties of bacterial biofilms is required to more fully understand the processes of biofilm formation such as initial adhesion or detachment. The main contribution of this article is to demonstrate the use of homogenization techniques to compute mechanical parameters of Pseudomonas aeruginosa PAO1 biofilms. For this purpose, homogenization techniques are used to analyze freeze substitution electron micrographs of the biofilm cross‐sections. The concept of a representative volume element and the study about his representativeness allows us to determine the optimal size in order to analyze these biofilm images. Results demonstrate significant heterogeneities with respect to stiffness and these can be explained by varying cell density distribution throughout the bacterial biofilms. These stiffness variations lead to different mechanical properties along the height of the biofilm. Moreover, a numerical shear stress test shows the impact of these heterogeneities on the detachment process. Several modes of detachment are highlighted according to the local strain energy in the different parts of the biofilm. Knowing where, and how, a biofilm may detach will allow better prediction of accumulation and biomass detachment. Biotechnol. Bioeng. 2013; 110: 1405–1418. © 2012 Wiley Periodicals, Inc.     

Yeast hydrolysate supplement increases starvation vulnerability of Queensland fruit fly

Post‐teneral diets containing yeast hydrolysate are reported to increase longevity, reproductive development and sexual performance of Queensland fruit fly (‘Q‐fly’) Bactrocera tryoni Froggatt (Diptera: Tephritidae). Consequently, diets including yeast hydrolysate are recommended for sterile Q‐flies before release in sterile insect technique (SIT) programmes. However, in some tephritids, diets including yeast hydrolysate are associated with an increased vulnerability to starvation. In the present study, the effects of yeast hydrolysate supplementation before release are considered with respect to the longevity of released Q‐fly when food becomes scarce. Experiments are carried out in three settings of varying resemblance to field conditions: 5‐L laboratory cages, 107‐L outdoor cages and 14 140‐L field cages containing potted citrus trees. In all experimental settings, compared with flies that received only sucrose, male and female Q‐flies that are provided with yeast hydrolysate during the first 2 days of adult life have a significantly shorter survival when subsequently deprived of food. Yeast supplementation appears to commit Q‐flies to a developmental trajectory that renders them more vulnerable to starvation. The practical significance of these findings for SIT depends on how often the releases are carried out under conditions in which Q‐flies experience extreme food shortages in the field.     

Reliability of bulky DNA adducts measurement by the nuclease P1 32P-post-labelling technique

The aim was to assess the reliability of bulky DNA adducts measurement by means of the ³²P-post-labelling assay. The research design consisted of an intramethod reliability study. Buffy coats from 41 subjects were used to obtain two aliquots of 1–5 μg DNA for each subject; bulky DNA adducts were measured using the nuclease P1 ³²P-post-labelling technique. The reliability of the measurement was assessed by means of the intraclass correlation coefficient (ICC), the distribution of the differences between the two measurements and the limits of agreement. The estimated ICC was 0.977, with a 95% confidence interval between 0.921 and 0.977. The limits of agreement were ±0.44 (DNA adducts per 10⁸ nucleotides). Only three subjects had differences lying out of such limits. Bulky DNA adduct levels measured by the ³²P-post-labelling technique showed good reliability. Only one measurement is needed to use DNA adducts as a biomarker of exposure and, possibly, cancer risk. Besides, as a validation analysis, ³²P-post-labelling measurements can be repeated in only 20–30% of samples.