影响小麦籽粒角质率因素的初探

小麦籽粒角质率是小麦品质的一个重要外观指标，籽粒角质率的变化受环境影响极大。本文研究了不同土壤质地、灌溉次数、不同肥料与用量、播种密度以及收获期与小麦角质率变化的关系。结果表明，在内蒙古河套地区选择壤土、适当减少灌水次数特别是避免浇麦黄水、增加N肥施用量、密度控制在600万／hm^2左右、选择在完熟期收获，均有利于提高小麦角质率。     

牦牛乳中脂肪测定方法比较

用“哥特里一罗紫法”、“酸水解法”和“快速测定法”（乳成份分析仪法）三种方法进行牦牛乳中脂肪含量的测定,经对测定结果的比较分析得出：在测定牦牛乳中的脂肪含量时“哥特里．罗紫法”优于“酸水解法”;而在现场牦牛乳中脂肪含量测定时宜用“乳成分分析仪”进行快速测定。     

Performance of pedotransfer functions in predicting soil water characteristics of soils in Norway

Abstract

Pedotransfer functions (PTFs), predicting the soil water retention curve (SWRC) from basic soil physical properties, need to be validated on arable soils in Norway. In this study we compared the performance of PTFs developed by Riley (1996), Rawls and Brakensiek (1989), Vereecken et al. (1989), Wösten et al. (1999) and Schaap et al. (2001). We compared SWRCs calculated using textural composition, organic matter content (SOM) and bulk density as input to these PTFs to pairs of measured water content and matric potential. The measured SWRCs and PTF input data were from 540 soil horizons on agricultural land in Norway. We used various statistical indicators to evaluate the PTFs, including an integrated index by Donatelli et al. (2004). The Riley PTFs showed good overall performance. The soil specific version of Riley is preferred over the layer specific, as the latter may introduce a negative change in water content with increasing matric potential (h). Among the parameter PTFs, Wösten's continuous PTF showed the overall best performance, closely followed by Rawls&B and Vereecken. The ANN-based continuous PTF of Schaap showed poorer performance than its regression based counterparts. Systematic errors related to both particle size and SOM caused the class PTFs to perform poorly; these PTFs do not use SOM as input, and are therefore inappropriate for soils in Norway, being highly variable in SOM. The PTF performance showed little difference between soil groups. Water contents in the dry range of the SWRC were generally better predicted than water contents in the wet range. Pedotransfer functions that included both SOM and measured bulk density as input, i.e. Wösten, Vereecken and Rawls&B, performed best in the wet range.     

Implications of Azospirillum brasilense inoculation and nutrient addition on maize in soils of the Brazilian Cerrado under greenhouse and field conditions

The combination of nitrogen and Azospirillum can ensure greater nutrient absorption and crop yield in agricultural areas using high technology. Thus, the objective was to evaluate maize response to Azopirillum brasilense (AZ) inoculation and nutrient (macronutrients and micronutrients) application under greenhouse and field conditions in clay and sandy soils of the Brazilian Cerrado. In the greenhouse assays, the following parameters were measured: shoot dry weight (SDW), root dry weight (RDW), and root volume (RV). In the field experiments, the maize yield was determined after drying the grains at 60 °C for 48 h. In clay soil, there was a significant increase in the SDW, RDW and RV in the treatment with AZ concentrated (10¹¹ cells ml⁻¹ of inoculum) when compared with the control treatment and the treatment with AZ diluted (10⁶ cells ml⁻¹ of inoculum). In this soil, adding micronutrients did not affect the maize response under greenhouse conditions. In sandy soil, there was no difference between the AZ treatment and the control, except for treatments where nutrients and AZ were both added leading to a significant increase in the maize response. In both soils, the RV:RDW ratio was higher in the treatment with AZ concentrated compared to that in the treatment with AZ diluted, but the yield response depended on the addition of nutrients. Inoculation with A. brasilense gave comparable yield to the nitrogen treatment. The grain production was increased by 29% in the treatment with A. brasilense and nitrogen compared to nitrogen fertilization alone. In this study, the yield response was affected significantly when maize was inoculated with A. brasilense, but this response was dependent on the soil type under greenhouse conditions.     

单环压力渗透仪两个积水深度程序的数值模拟及试验验证

The two-ponding depth （TPD） analysis procedure of single-ring infiltrometer data can yield invalid results, i.e., negative values of the field-saturated soil hydraulic conductivity or the matric flux potential, denoting failure of the two-level run. The objective of this study was to test the performance of the TPD procedure in analyzing the single-ring infiltrometer data of different types of soils. A field investigation carried out in western Sici]y, Italy, yielded higher failure rates （40%） in two clay loam soils than in a sandy loam soil （25%）. A similar result, i.e., fine-textured soils yielding higher failure rates than the coarse-textured one, was obtained using numerically simulated infiltration rates. Soil heterogeneity and reading errors were suggested to be factors determining invalid results in the field. With the numerical data, allowing a less generic definition of soil heterogeneity, invalid TPD results were occasionally obtained with the simultaneous occurrence of a high random variation （standard deviation ≥ 0.5） and a well developed structural correlation for saturated hydraulic conductivity （correlation length 〉 20 cm）. It was concluded that a larger number of replicated runs should be planned to characterize fine-textured soils, where the risk to obtain invalid results is relatively high. Large rings should be used since they appeared more appropriate than the small ones to capture and average soil heterogeneity. Numerical simulation appeared suitable for developing improved strategies of soil characterization for an area of interest, which should also take into account macropore effects.     

高静压杀菌对不同形状果块的黄桃罐头质地的影响

该文在保证黄桃罐头无菌的前提下,研究了高静压杀菌技术对不同形状果块的黄桃罐头质地的影响。首先通过测定不同的高静压条件下黄桃罐头细菌总数、霉菌和酵母数的变化,并结合热杀菌时间,确定出质地研究的杀菌条件为600 MPa/20 min。再将不同形状果块的黄桃罐头在600 MPa下处理20 min后,以90℃,20 min热杀菌的黄桃罐头为对照,通过测定2种杀菌方式前后及低温和常温贮藏过程中不同形状果块的黄桃罐头果肉硬度、汤汁黏度及果肉细胞结构的变化,得出了高静压杀菌结合低温贮藏技术在罐头质地保持方面的优越性。研究结果表明：高静压杀菌的3种形状果块的罐头果肉硬度分别为热杀菌的2.8倍（“条状”）,3.1倍（“丁状”）和2.9倍（“块状”）,高静压杀菌后“块状”黄桃罐头汤汁黏度较小,果肉细胞结构较完整;且高静压杀菌后低温贮藏（4±1）℃的黄桃罐头质地品质均优于常温贮藏（25±1）℃。在3种形状果块的黄桃罐头中,无论是低温贮藏（4±1）℃还是常温贮藏（25±1）℃,“块状”的黄桃罐头其果肉硬度最大,汤汁黏度最小,细胞结构破坏程度最小,是最适宜的黄桃罐头加工形状。研究结果为高静压技术取代热杀菌应用于黄桃罐头的加工提供了理论依据。     

Fractionation method for the determination of the root length of field-grown wheat

Abstract

Extract

Studies on the root system which are essential to understand the nutrient and water uptake by plant, are very difficult because the root system in the soil can not be observed directly unlike the shoot system. Even basic parameters, such as root length and root surface area cannot be measured easily.     

Decontamination of Chromium by Farm Yard Manure Application in Spinach Grown in Two Texturally Different Cr-Contaminated Soils

ABSTRACT

Chromium (Cr) is an environmental pollutant and its accumulation up to toxic levels in the soil and plants by applying irrigation with untreated industrial effluents has become a major problem throughout the world, especially in developing countries like India. Various inorganic as well as organic compounds are known for their ability to reduce mobilization of heavy metals in soils for plant uptake and leaching to ground water. The present study was undertaken under controlled glasshouse conditions to assess the effectiveness of farm yard manure (FYM) applications (equivalent to 0, 1, and 2% organic matter on w/w basis) to ameliorate Cr toxicity in spinach grown in two texturally different soils (silty loam and sandy) contaminated artificially with five levels of Cr (0, 1.25, 2.5, 5.0, and 10.0 mg Cr kg^{? 1} soil as K₂Cr₂O₇). The diethylene triamine pentaacetic acid (DTPA)-extractable Cr in soil (before seeding and after harvest), Cr concentration, and its uptake by shoots and roots of spinach increased with increasing level of applied Cr. Roots accumulated more Cr than shoots, which depicts limited translocation of Cr from roots to shoots. A significant decrease was observed in dry matter yield (DMY) of shoots as well as roots by raising levels of applied Cr (0 to 10 mg Cr kg^{? 1} soil) in both soils, but the extent of the DMY decrease was higher in the sandy loam soil. Application of FYM showed mitigating effects on Cr toxicity. The DMY was higher in the presence of FYM, than its absence, at all rates of applied Cr in both soils. The FYM application caused decline in the DTPA-extractable Cr in soil, and concentration of Cr and its uptake by shoots and roots of spinach at a given level of applied Cr. The magnitude of Cr toxicity and its amelioration by FYM application was higher in sandy soil compared to silty loam soil. The results of this study indicated that FYM application to the soil could be used as an effective measure for reducing Cr toxicity to crop plants in Cr-contaminated soils irrigated by untreated industrial effluents.     

播期对四川盆地杂交籼稻米饭食味品质的影响

为明确播期对四川盆地杂交籼稻米饭食味品质的影响,以杂交籼稻宜香优2115、F优498和川优6203为试验材料,在四川大邑、南部、射洪3个地点设置大田播期试验,利用米饭食味计和硬度黏度仪,研究了不同地点间播期对杂交籼稻米饭外观、口感、综合评分、以及硬度和黏度的影响。结果表明:(1)杂交籼稻的米饭食味品质是地点、品种、播期及其互作共同作用的结果。(2)不同播期间,米饭外观、口感和综合评分均表现为宜香优2115>川优6203>F优498,硬度值则以F优498最高,优质品种宜香优2115米饭食味品质明显较优;不同地点间,适宜推迟播期则可提高米饭外观、口感、综合评分,进而提高米饭食味品质。(3)相关分析表明,综合评分与播种-抽穗期的积温和降雨量分别呈极显著正相关和显著负相关,与抽穗-成熟期积温和日照时数,以及全生育期降雨量呈显著或极显著负相关。(4)GGE模型分析表明,在大邑播期推迟10 d具有较好的综合评分且稳定性好;在南部和射洪,播期推迟10~20 d具有较高的综合评分,且稳定性较好。综合来看,在四川盆地,播期推迟10~20 d可以使水稻灌浆结实期处于较合理的温光环境,进而有效改善杂交籼稻的米饭食味品质,提高综合评分和稳定性。     

抹茶味面筋蛋白基口香糖的研制

以小麦面筋为胶基原料,以水、甘油、复合甜味剂(山梨醇和麦芽糖醇)以及抹茶4种辅料研制抹茶味面筋蛋白基口香糖。通过单因素试验确定水、甘油、复合甜味剂(山梨醇和麦芽糖醇)以及抹茶4种辅料的合适用量,再选取用水量、甘油用量、山梨醇和麦芽糖醇比例3个因素进行均匀试验以优化配方。通过感官评定确定抹茶味面筋蛋白基口香糖的最佳配方,并制作相关的产品,最后进行质构分析评判产品性能。感官评定结果表明,口香糖的最佳配方为:小麦面筋蛋白10 g,薄荷冰0.02 g,β-环糊精0.8 g,抹茶0.2 g,水11 g,甘油1.2 g,山梨醇和麦芽糖醇各为2.5 g。对口香糖的质构测定结果进行回归和相关性分析,表明测定结果能较好地预测口香糖的硬度、弹性、黏聚性和咀嚼性,但口香糖的硬度、弹性、黏聚性与辅料之间(除加水量与硬度、咀嚼性、黏聚性3个因素之间),相关性不显著。