Variation in avenanthramide content in spring oat over multiple environments

Avenanthramides (AVNs), a group of phytochemicals which are unique to oats, provide health benefits through antioxidant activity and other bioactivities. In this study, we explored genotype-by-environment interactions and heritability for AVN concentrations in oats. Avenanthramide concentrations were quantified for 100 breeding lines and cultivars at three locations over two years. While year and environment had an influence on AVN concentrations, with the influence of year being more apparent than that of environment within a year, genotype had the largest impact on AVN concentration. All three major AVNs were found to be heritable. Two methods of calculating heritability on a line mean basis were used. The statistical method yielded heritability estimates of 0.34, 0.39, and 0.41 for AVN 2c, AVN 2p, and AVN 2f, respectively. By comparison the traditional plant breeding method yielded heritability estimates of 0.82, 0.88, and 0.89 for AVN 2c, AVN 2p, and AVN 2f, respectively, indicating that expected gains will be dependent on the scale of the breeding program, the number of target environments, and climate variability. The estimated heritabilities and the 11-fold range in AVN concentrations in the 100 genotypes studied provided evidence that variability for AVN concentration should allow breeding progress for higher AVN concentration.     

Ultra-fast separation of wheat glutenin subunits by reversed-phase HPLC using a superficially porous silica-based column

A relatively new, unique column packing material for reversed-phase high-performance liquid chromatography (RP-HPLC) was evaluated for rapid separation of wheat glutenin protein subunits. The product named “Poroshell” by the manufacturer consists of a solid core and a porous coat instead of solid silica spheres used in conventional RP-HPLC column packing. This architecture favours rapid mass transfer, facilitating faster reversed-phase separations of biomolecules compared to conventional silica columns. The main objective of this study was to evaluate the quality of separations of glutenin subunits (GS), as well as to optimize conditions to produce the fastest possible run times without sacrificing resolution using a Poroshell 300SB-C₈ 2.1×75 mm column. The stability of GS separations over time was also assessed. Two different bread wheat genotypes were used for optimization of separation conditions and six more common and durum wheat genotypes possessing different subunit combinations were used for further evaluation. Glutenin protein was extracted with 0.08 M Tris–HCl buffer (pH 7.5) containing 50% 1-propanol under reducing conditions after pre-extraction of soluble proteins with 50% 1-propanol. Optimization of GS resolution and sample throughput by RP-HPLC was assessed in response to variation in eluent flow rate, acetonitrile (ACN) gradient, and column temperature. The best resolution of both HMW- and LMW-GS was obtained in 13 min using a 23–44% ACN gradient with a flow rate of 0.7 mL/min at 65 °C. Subunit elution times and integrated areas were highly repeatable even after several hundred injections. Highly satisfactory separation of HMW-GS and quantification of ratio of HMW- to LMW-GS were achieved in less than 4 min per sample using a modified HPLC gradient. Ratio of HMW- to LMW-GS was unaffected by the speed of the separations. As well, the elution order of HMW- and LMW-GS was unaffected by the rapid analysis, compared to conventional RP-HPLC separations, so no new learning was required for interpreting chromatograms and classification of subunits. The rapid RP-HPLC method using the Poroshell column appears to be very well suited for routine quantification of HMW-GS and LMW-GS especially for purposes of wheat quality screening and wheat cultivar development activities where large numbers of samples are typically encountered.     

简易HPLC法测定甜菊叶中甜菊糖苷

一般甜菊叶中甜菊糖苷的HPLC检测样品处理复杂,采用简易超声波水提取法处理样品,建立快捷分析方法。甜菊糖苷在300~1500μg/mL内呈线性关系,相关系数为0.9998,平均加标回收率98.32%,相对标准偏差0.63%。该方法操作简单、重复性好、稳定性好、灵敏度高,可为甜菊叶中甜菊糖苷的测定提供参考。     

氯氰菊酯与p53-DNA相互作用的光谱研究

采用紫外、荧光分光光度法研究了农药氯氰菊酯与人类肿瘤抑制基因p53-DNA之间的相互作用.实验出现紫外减色、荧光猝灭等结果表明氯氰菊酯可能是以嵌插模式与p53-DNA结合作用;紫外变温实验得出p53-DNA熔点温度略有升高等结果则进一步证实氯氰菊酯是部分嵌插入DNA的沟区,影响了DNA的双螺旋结构的稳定性.     

试析晏式平民教育思想的历史意义及对现代农村教育的价值

晏阳初平民教育思想的目标与对象非常明确,教育内容与方式行之有效。在历史上平民教育思想丰富了乡村教育的内容,实现了教育对象的大众化,教育内容的实用化,教学方法的多样化;促进了教育者信仰的坚定与能力的提高;激发了受教育民众的思想与活力。晏式的平民教育思想对现代农村教育仍有积极的价值导向:现代代农村教育需要"平教专家"的指导,实现农业现代化;需要"四大教育"的推进,实现农民市民化;需要"三大方式"的连锁推进,实现农村城市化,从而更好促进城乡一体化的实现。     

Decomposition of a Native Shrub,Piliostigma reticulatum,Litter in Soils of Semiarid Senegal

Developing effective management strategies that restore degraded soils requires an evaluation of the quality of the litter residues. This study relates the chemical composition of the biomass components to the decomposition rates for Piliostigma reticulatum (DC.) Hochst., a native shrub, under field and laboratory conditions. The rates were determined by mass loss. The changes in the specific surface area of the residue in relation to mass loss ranged from 15 X 10 -5 to 45 X 10 -5 which was similar to crop residues in other studies. At field conditions, P. reticulatum mass loss was higher (80% of the initial mass lost over eight months) than that under controlled conditions (50%). Such fast decomposition of residues offers the potential for farmers to stop burning these residues because high amounts of residues will not likely accumulate and cause interference with tillage and planting operations. Further studies are needed on the role of soil fauna on decomposition, mineralization of nutrients from these residues, and the potential for incorporating residues into the system without burning.     

Sugar analysis with the shaffer‐somogyi micro‐analysis,high performance liquid chromatography and enzymatic analysis in crop samples

Abstract

To evaluate the reliability of the Shaffer‐Somogyi (SS) micro‐analysis of reducing sugars, extracts of 14 dried crop samples were analyzed before and after hydrolysis in 0.05 N ^H ₂SO₄with this method, with High Performance Liquid Chromatography (HPLC) and with an enzymatic glucose and fructose assay. The values, obtained with the SS micro‐analysis were for many samples higher than those, obtained with HPLC, suggesting that other compounds than sugars, present in certain plant tissues, respond in this non‐specific method. Enzymatic analysis tended to give lower values for sugar content than HPLC. It is recommended, that routine analysis of crop samples with the SS micro‐analysis is preceeded by analysis with HPLC to assess the contribution of non‐sugars to the outcome of the former.     

色谱分析技术在食品检测中的应用

色谱分析法以其良好的分离效果,结合其他分析手段在现代仪器分析中占有重要的地位。该文介绍了色谱分析技术在食品检测方面应用的最新进展,主要集中在色谱技术、联用技术和元素形态分析等方面。      

内蒙古绒山羊骨骼肌蛋白差异表达谱分析

【目的】研究内蒙古绒山羊背最长肌、臂三头肌和臀肌的蛋白差异表达谱。【方法】以3只在相同背景下饲养的绒山羊成年母羊为研究对象,屠宰后取背最长肌、臂三头肌和臀肌3个部位骨骼肌,采用差异双向电泳方法建立蛋白质谱,找出17个差异表达蛋白点,并进行质谱分析。【结果】成功鉴定并匹配到15个差异表达蛋白,其中9个与山羊肌肉发育相关。背最长肌中发现的位于FGF2反义链的蛋白的功能主要是独立控制FGF2的表达,同时具有激素调节和抗增殖的作用;背最长肌和臂三头肌中发现的轻链肌球蛋白(MyLC)家族成员,其类型在2种肌肉组织中不同,功能是控制肌肉收缩。背最长肌和臂三头肌中的MyLC蛋白分子质量存在差异。【结论】建立了绒山羊骨骼肌差异蛋白谱,挖掘到了与肉质相关的蛋白,其主要为控制肌肉收缩的结构蛋白。     

20%呋虫胺悬浮剂的高效液相色谱分析

为了解决呋虫胺悬浮剂含量在分析上方法不足,以及采用液相色谱法测定时流动相选择,仪器条件的确定时所遇到的问题,采用岛津LC-10AT液相色谱仪为基础,利用2.5 cm×4.6 mm不锈钢,内装C18、5 μm填充物,乙腈+水+冰乙酸+三乙胺为流动相对呋虫胺悬浮剂有体的含量进行检测。结果表明采用该流动相以及仪器条件下,呋虫胺有效体含量的不存在异构体峰重叠现象。主峰与杂质峰的分离度最好,峰形良好。此次研究证明,20%呋虫胺悬浮剂分析方法的提出不仅填补了该烟碱类杀虫剂总含量分析方法的空白,而且测定便捷、准确、可行,利于生产企业用来质控。