平阳霉素Pingyangmycin对大麦的诱变效应

本试验以平阳霉素为诱变剂处理大麦种子,研究了该诱变剂对大麦的诱变效应及其适宜的浓度。结果表明,平阳霉素是一种有效的诱变剂,诱变效应与EMS相近,而且作用的有效期长,毒性小,它不仅能引起以染色体断片为主的较高频率的染色体畸变,而且能够在M_2产生较高频率的性状变异,特别是产生较高频率的早熟和高分蘖力的有益突变。平阳霉素对大麦诱变的适宜浓度为30μg/ml左右。     

Optimizing conditions for the extraction of pigments in cochineals (Dactylopius coccus Costa) using response surface methodology

A simple method was developed for the extraction and determination of color pigments in cochineals (Dactylopius coccus Costa). The procedure was based on the solvent extraction of pigments in insect samples using methanol:water (65:35, v:v) as extractant. Two-level factorial design was used in order to optimize the solvent extraction parameters: temperature, time, methanol concentration in the extractant mixture, and the number of extractions. The results suggest that the number of extractions is statistically the most significant factor. The separation and determination of the pigments was carried out by high-performance liquid chromatography with UV-visible detection. Because the absorption spectra of different pigments are different in the visible region, it is convenient to use a diode array detector to obtain chromatographic profiles that allow for the characterization of the extracted pigments.     

基于Retinex图像增强的不同光照条件下的成熟荔枝识别

为了满足自然环境下荔枝采摘机器人视觉定位系统的有效性和实时性的要求,针对不同光照条件的荔枝彩色图像,采用基于双边滤波的Retinex图像增强算法凸显图像中的荔枝果实和果梗,对增强处理后的图像在HSI颜色空间中进行H分量旋转的处理,再对旋转处理后的H分量进行Otsu自动阈值分割去除荔枝图像果实和果梗外的复杂背景;然后通过将双三次插值算法和传统的模糊C均值（FuzzyC-Mean）算法融合,对去背景后的荔枝图像在YCbCr颜色空间中进行Cr分量模糊聚类分割,实现荔枝果实和果梗的识别。荔枝图像的分割试验结果表明：该算法对晴天顺光、逆光、遮阴、阴天顺光等光照条件的荔枝图像能够有效地分割,对阴天弱光照、果实被遮阴条件下的荔枝也能较好的识别,并保持荔枝果实和果梗区域的完整性,4种光照条件荔枝图像分割正确率分别为96%、90%、89.3%和88.9%,成熟荔枝识别的正确率达到了90.9%,该研究为水果采摘机器人的室外作业的实时性和有效性提供指导。     

Using the acetyl bromide assay to determine lignin concentrations in herbaceous plants: some cautionary notes

The acetyl bromide assay was developed to provide a rapid and sensitive method for quantifying lignin in woody plant species. The original procedure cautioned against prolonged reaction times and advised keeping the reaction temperature at 70 degrees C to prevent excessive carbohydrate degradation that would skew the absorption spectra. Characterization of the reaction conditions revealed that the acetyl bromide reagent readily degrades xylans, a prominent polysaccharide group within all lignified plants. This degradation results in increased absorbance in the 270-280 nm region that is used to quantify lignin. The degradation of xylans is temperature dependent and is exacerbated by the addition of perchloric acid. Lowering the reaction temperature to 50 degrees C and increasing the reaction time from 2 to 4 h allows complete lignin solubilization but minimizes degradation of the xylans.     

Isolation and determination of alpha-dicarbonyl compounds by RP-HPLC-DAD in green and roasted coffee

Glyoxal, methylglyoxal, and diacetyl formed as Maillard reaction products in heat-treated food were determined in coffee extracts (coffee brews) obtained from green beans and beans with different degrees of roast. The compounds have been reported to be mutagenic in vitro and genotoxic in experimental animals in a number of papers. More recently, alpha-dicarbonyl compounds have been implicated in the glycation process. Our data show that small amounts of glyoxal and methylglyoxal occur naturally in green coffee beans. Their concentrations increase in the early phases of the roasting process and then decline. Conversely, diacetyl is not found in green beans and forms later in the roasting process. Therefore, light and medium roasted coffees had the highest glyoxal and methylglyoxal content, whereas dark roasted coffee contained smaller amounts of glyoxal, methylglyoxal, and diacetyl. For the determination of coffee alpha-dicarbonyl compounds, a reversed-phase high performance liquid chromatography with a diode array detector (RP-HPLC-DAD) method was devised that involved the elimination of interfering compounds, such as chlorogenic acids, by solid phase extraction (SPE) and their derivatization with 1,2-diaminobenzene to give quinoxaline derivatives. Checks of SPE and derivatization conditions to verify recovery and yield, respectively, resulted in rates of 100%. The results of the validation procedure showed that the proposed method is selective, precise, accurate, and sensitive.     

Optimization of tannin extraction from infant foods

The design of experiments (DOE) was used in the development of a laboratory procedure for the extraction of tannins from three infant food types comprising different ingredients of vegetable origin and meat. The diversity of vegetables included in the product formulas required the use of DOE to establish parameters that maximize the recovery of tannins using a central composite rotatable design. Once the experimental results from the DOE were obtained, response surface methodology was used to find the best analytical conditions for samples comprising different ingredients. Sample weight was found to be a critical factor in tannin extraction from foods. Different optimal conditions were obtained for samples including soya in the formula.     

基于近邻传播算法的茶园土壤墒情传感器布局优化

针对节水灌溉的土壤墒情传感器布局问题,提出了基于近邻传播算法(affinity propagation,AP聚类算法)的优化布局策略。策略在保证茶园传感网络全覆盖的基础上,实时采集试验区各节点的土壤墒情数据,构建节点土壤含水率的相似度矩阵,并迭代计算各节点的吸引度和归属度值,得出聚类数和聚类中心。结果表明,采用AP聚类算法对试验区域传感器进行优化布局,优化了传感器数量和位置,使传感器数量由25个减少到2个。在试验区随机采集土壤相对含水率,经验证,聚类中心节点的土壤相对含水率与试验区平均值相近,相对偏差近为0.76%,表明聚类中心节点的土壤墒情数据具有代表性。该方法有效降低了数据的冗余度,节约了系统成本。     

Cluster analysis applied to the exploratory analysis of commercial spanish olive oils by means of excitation-emission fluorescence spectroscopy

Olive oil fluorescence is related to oil composition. Here it is shown that the natural clustering of different types of commercial Spanish olive oils depends on their fluorescence excitation-emission matrices (EEMs). Fifty-six commercial samples of olive oil (29 virgin olive oils, 20 pure olive oils, and 7 olive-pomace oils) were used. The clustering method was hierarchical agglomerative clustering using the Euclidean distance as a similarity measure and the average linkage. Two spectral ranges were considered (which either contained the fluorescence peak of the chlorophylls or did not), and various methods for preprocessing the fluorescence spectra were compared. The oils were clearly distinguished using the unfolded EEMs measured between lambda(ex) = 300-400 nm and lambda(em) = 400-600 nm. The optimal preprocessing was normalization of the unfolded spectra followed by column autoscaling. Also shown are the advantages of using second-order data (EEMs) instead of first-order data (a single fluorescence spectrum) for each sample.     

构建县域早稻氮磷钾施肥的系统聚类方法研究

【目的】 为建立县域早稻氮磷钾施肥类别,探讨多点肥效试验资料的定量分类方法。 【方法】 以仙游县 26 个早稻“3414”设计的氮磷钾肥试验结果为例,探讨不同系统聚类分析方法的适用性及其类别间差异显著性。 【结果】 对生产条件和生产技术水平差异较小的县域肥效试验资料,以能使类别间距离空间扩展范围较大的欧氏距离–离差平方和法为最佳系统聚类分析方法,可将 26 个试验资料清晰地分成 3 类,分别对应于该县的高产、中产和低产稻田类型;两两类别间的空白区产量和平衡施肥产量均达到差异显著水平,且在 95% 置信区间下,稻谷产量水平在 3 个类别间几乎不出现交叉重叠。在此基础上,根据 3 种施肥类别对应的试验点资料,分别建立三元二次多项式类特征肥料效应方程,进而得到这 3 个施肥类别的推荐施肥量。 【结论】 欧氏距离–离差平方和法系统聚类分析是县域多点肥效试验资料的一种有效定量分类方法,可将仙游县早稻分为具有统计显著性差异的 3 个氮磷钾施肥类别。      

Accounting for the effects of water and the environment on proximally sensed vis–NIR soil spectra and their calibrations

Visible–near infrared (vis–NIR) spectroscopy can be used to estimate soil properties effectively using spectroscopic calibrations derived from data contained in spectroscopic databases. However, these calibrations cannot be used with proximally sensed (field) spectra because the spectra in these databases are recorded in the laboratory and are different to field spectra. Environmental factors, such as the amount of water in the soil, ambient light, temperature and the condition of the soil surface, cause the differences. Here, we investigated the use of direct standardization (DS) to remove those environmental factors from field spectra. We selected 104 sensing (sampling) sites from nine paddy fields in Zhejiang province, China. At each site, vis–NIR spectra were recorded with a portable spectrometer. The soils were also sampled to record their spectra under laboratory conditions and to measure their soil organic matter (SOM) content. The resulting data were divided into training and validation sets. A subset of the corresponding field and laboratory spectra in the training set (the transfer set) was used to derive the DS transfer matrix, which characterizes the differences between the field and laboratory spectra. Using DS, we transferred the field spectra of the validation samples so that they acquired the characteristics of spectra that were measured in the laboratory. A partial least squares regression (PLSR) of SOM on the laboratory spectra of the training set was then used to predict both the original field spectra and the DS‐transferred field spectra. The assessment statistics of the predictions were improved from R² = 0.25 and RPD = 0.35 to R² = 0.69 and RPD = 1.61. We also performed independent predictions of SOM on the DS‐transferred field spectra with a PLSR derived using the Chinese soil spectroscopic database (CSSD), which was developed in the laboratory. The R² and RPD values of these predictions were 0.70 and 1.79, respectively. Predictions of SOM with the DS‐transferred field spectra were more accurate than those treated with external parameter orthogonalisation (EPO), and more accurate than predictions made by spiking. Our results show that DS can effectively account for the effects of water and environmental factors on field spectra and improve predictions of SOM. DS is conceptually straightforward and allows the use of calibrations made with laboratory‐measured spectra to predict soil properties from proximally sensed (field) spectra, without needing to recalibrate the models.     

Analysis of Fatty Acids in Kernel,Flour, and Oil Samples of Maize by NIR Spectroscopy Using Conventional Regression Methods

High cost and painstaking procedures associated with fatty acid analyses of maize kernel necessitate the use of alternative methods. NIR spectroscopy offers advantages in this respect for a variety of areas such as plant breeding, food and feed industries, and biofuel production, in which different forms of maize kernel (e.g., intact kernel, flour, or oil) are used as material. We investigated the possibility of estimating maize oil quality traits by using different samples (intact kernel, flour, and oil) and conventional regression methods (multiple linear regression [MLR] and partial least squares regression [PLSR]) applied to their NIR spectra. MLR and PLSR calibration models were developed for oleic acid, linoleic acid, oleic/linoleic acid ratios, total monounsaturated fatty acid, total polyunsaturated fatty acid (PUFA), and total saturated fatty acid by analyzing 120 maize samples. Robustness in terms of prediction accuracy of the models developed here was tested with a reserved set of samples (n = 30). The results suggested that fatty acids could be possibly estimated by calibrations developed from flour and oil samples with a high degree of accuracy, whereas intact samples did not offer satisfactory results. PLSR and MLR methods gave better results in flour and oil samples, respectively. PUFA was the trait that was most successfully estimated from both flour (for the PLSR model, standard error of the estimate [SEP] of 1.78%, relative performance to deviation [RPD] of 3.09, R² = 0.93) and oil (for the MLR model, SEP of 0.85%, RPD of 6.52, R² = 0.98) samples. We concluded that sample type and chemometric method should be handled as important factors in calibration development, and the effects of these factors may vary depending on the trait being analyzed.     

Influence of pH, iron source, and Fe/ligand ratio on iron speciation in lignosulfonate complexes studied using Mössbauer spectroscopy. Implications on their fertilizer properties

Iron chlorosis is a very common nutritional disorder in plants that can be treated using iron fertilizers. Synthetic chelates have been used to correct this problem, but nowadays environmental concerns have enforced the search for new, more environmentally friendly ligands, such as lignosulfonates. In this paper, Fe coordination environment and speciation in lignosulfonate (LS) complexes prepared under different experimental conditions were studied by (57)Fe M?ssbauer spectroscopy in relation to the Fe-complexing capacities, chemical characteristics of the different products, and efficiency to provide iron in agronomic conditions. It has been observed that the complex formation between iron and lignosulfonates involves different coordination sites. When Fe(2+) is used to prepare the iron-LS product, complexes form weak adducts and are sensitive to oxidation, especially at neutral or alkaline pH. However, when Fe(3+) is used to form the complexes, both Fe(2+) and Fe(3+) are found. Reductive sugars, normally present in lignosulfonates, favor a relatively high content of Fe(2+) even in those complexes prepared using Fe(3+). The formation of amorphous ferrihydrite is also possible. With respect to the agronomical relevance of the Fe(2+)/Fe(3+) speciation provided by the M?ssbauer spectra, it seems that the strong Fe(3+)-LS complexes are preferred when they are applied to the leaf, whereas root uptake in hydroponics could be more related with the presence of weak bonding sites.     

基于K均值聚类和开闭交替滤波的黄瓜叶片水滴荧光图像分割

为了监测温室黄瓜叶片湿润情况以计算叶片湿润时间并用于病害预警,利用K-均值聚类算法实现黄瓜叶片的水滴荧光图像分割。选择人工气候室培育的健康且洁净的黄瓜叶片作为试验试材,采用移液枪向叶面、叶缘部位上滴水,模拟不同的叶片湿润情形,使用荧光成像仪蓝光镜头在白天（07：00）和夜晚（18：00）分别采集图像。应用 K-均值聚类算法在L*a*b颜色空间对水滴图像进行分割,首先要将原始图像由RGB颜色空间转换到L*a*b颜色空间,然后在在L*a*b颜色空间中利用a*b*二维数据空间的颜色差异,以欧式距离度量像素间的相似度,使用K均值对图像进行聚类,聚类得到的图像灰度化后进一步用数学形态学中的开闭交替滤波方法进行校正,最终完成图像分割。利用该方法对10幅含有不同水滴数量的黄瓜叶片荧光图像进行分割,为了验证该方法的有效性,分别采用基于H分量直方图分割算法、主动轮廓即C_V模型分割方法、融合K均值聚类和Ncut算法作对比试验。试验结果表明,该方法的平均匹配率、误分率相较于其他3种方法有明显的优势,平均匹配率为81.27%、平均误分率为9.57%,较之于其他3种方法,平均匹配率分别提高了44.11、11.50、10.90百分点,平均误分率分别降低了23.03、5.47和5.05百分点。该方法能够较为准确地将水滴从图像中分割出来,这为用计算机器视觉的方法监测黄瓜叶片的润湿时间提供了新的思路。     

Improved estimates of organic carbon using proximally sensed vis–NIR spectra corrected by piecewise direct standardization

We investigated the use of piecewise direct standardization (PDS) to remove the effects of water and other environmental factors from proximally sensed (field) visible–near infrared (vis–NIR) spectra. Our hypothesis was that the PDS‐standardized field spectra can be used to predict soil carbon effectively with calibrations derived from existing spectroscopic databases of spectra recorded in the laboratory on dried, ground and sieved samples. In our experiments we used field spectra recorded in situ with a portable spectrometer at 124 sites in 11 paddy fields in Zhejiang Province, China. We sampled the soil at these same sites, recorded their spectra in the laboratory and measured their soil organic carbon (SOC) contents with a conventional laboratory technique. Two‐thirds of the samples were used to relate the laboratory spectra to SOC by partial least squares regression (PLSR), and the remaining one‐third was used as an independent validation dataset. We selected a representative set of samples from corresponding field and laboratory spectra that we could use as the PDS transfer set. Piecewise direct standardization was used to relate each wavelength in the laboratory spectra to the corresponding wavelength and its neighbours in the field spectra. The field spectra of the validation samples were then corrected with PDS so that they acquired the characteristics of the spectra measured under laboratory conditions. The approach was evaluated by (i) quantifying the similarity between the PDS‐standardized spectra and their corresponding laboratory spectra, (ii) measuring the accuracy of their SOC predictions on the independent validation dataset and (iii) comparing these results with those of direct standardization (DS). Both PDS and DS led to considerable improvements in the predictions of SOC (R² = 0.71, R² = 0.60, respectively), compared with those with original field spectra (R² = 0.03). However, fewer transfer samples were needed with PDS to obtain similar results.     

同步辐射(软X射线)对冬小麦的诱变效应及机理研究 Ⅰ.同步辐射的辐射生物学效应

本文利用同步辐射 (软X射线 )辐照 3个冬小麦品种 ,从形态学、细胞学上研究了M1 代生物损伤和M2 代诱变效应。结果表明 :同步辐射抑制了M1 代幼苗、植株的生长 ,引起育性、结实率下降 ,M1 代的生理损伤在幼苗生长早期大于γ射线 ,在生育晚期则小于γ射线。细胞学研究表明 ,同步辐射抑制了细胞有丝分裂 ,明显地降低了细胞分裂指数 ,引起了细胞染色体的结构损伤 ,染色体畸变类型不同于γ射线 ,造成的生物损伤大于γ射线。同步辐射诱发了M2 代较宽的突变谱 ,出现了多种有益性状变异 ,适宜的诱变剂量范围为 2 0 0～ 2 5 0Gy ,小于γ射线 (2 5 0～ 35 0Gy)。     

Automatic flow system with voltammetric detection for diacetyl monitoring during brewing process

Diacetyl can be determined by adsorptive stripping voltammetry after derivatization with o-phenylenediamine. The method may be applicable to the determination of diacetyl in different foods, being a good alternative to other analytical methods. In this work an on-line automated analytical system for diacetyl determination in beer is described. A hanging mercury drop electrode voltammetric flow detector was used, and the analyte was determined without the traditional deoxygenation procedure. The method was successfully applied to the determination of diacetyl during beer fermentation and in the final product. The automation strategy used was based on a flow network similar to those used in multicommutated flow systems, with a pervaporation unit used for diacetyl separation. The developed system was tested in real conditions in the monitoring of brewing processes. The results obtained were similar to those obtained with the usual GC-ECD methodology in the 5-600 ppb range. The analytical rate of the developed method is about 12 determinations/h.     

Determination of the composition of gentamicin sulfates by 1H and 13C nuclear magnetic spectroscopy

The British Pharmacopoeia test controlling the composition of gentamicin sulfate is based on CW 60 MHz magnetic resonance spectroscopy. Application of this method to FT 90 MHz spectra was evaluated. Results clearly show the limitations of this technique and point out the need for more reliable assay methods. Thus a 13C nuclear magnetic resonance (NMR) procedure for quantitative analysis of gentamicin sulfate was developed. Ratios of 4 gentamicin components (C1, C2, C1a, and C2a) were obtained from peak height measurements of selected resonance signals in spectra recorded under steady-state conditions. Relative response factors were determined from spectra of a reference mixture or, alternatively, from spectra of the individual pure components. Results obtained by the 13C NMR method were in agreement with those obtained by liquid chromatography using pre-column derivatization.     

TILLING技术的原理、特点及其在点突变筛选中的应用

TILLING(TargetingInducedLocalLesionsINGenomes),是一种全新的反向遗传学研究方法,它提供了一种高通量、低成本规模化高效筛选化学诱变剂EMS诱发产生点突变的技术。本文简要介绍了TILLING的原理和技术优势,并对其在植物功能基因组学、突变分子育种和预测突变频率中的应用作了初步探讨。     

A contribution to environmental control in a glasshouse by a computer

The environmental conditions of plants grown in a glasshouse were controlled by a minicomputer (IBM-Series 1). The simulation model thus developed provides better analyses of the relationship between yield increase and control of environmental factors.The glasshouse used was in several sections, with all the necessary devices for controlling environmental conditions. Two different climatic regimes were stimulated in order to find a better agreement of simulated values with experimental data.The computer used can be applied to a system comprising several glasshouses where different crops are grown.     

One-Pot Construction of Titania-γ-AlOOH Nanocomposites Employed for Photocatalytic Degradation

A series of aluminum oxyhydroxide-incorporated titania composites were prepared by a one-pot synthetic procedure using aluminum tri-sec-butoxide as a precursor. The as-synthesized samples were characterized by Fourier transform infrared spectrophotometer, X-ray diffraction, thermogravimetry and differential scanning calorimetry, nitrogen physisorption, and scanning electron microscopy. It was identified that aluminum oxyhydroxide (??-AlOOH, or boehmite) was produced as aluminum matrix into which titania, commercially available P25, was incorporated. Photocatalytic activity of all nanocomposites was evaluated with respect to the photodecolorization of methyl orange under UV irradiation and almost complete decolorization was eventually achieved under optimum experimental conditions.