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91.
92.
A method for fractionating sorghum proteins using extraction solvents and techniques designed to obtain polymeric protein structures (especially disulfide linked) was developed. Extraction and separation conditions were optimized in terms of completeness of protein extraction, sample stability, and analytical resolution. After pre-extraction of albumins and globulins, a 3-step sequential procedure involving no reducing agents was applied to ground whole sorghum flour. The three fractions obtained represented proportionally different protein polymer contents and molecular weight distribution as evidenced by comparative size exclusion chromatography. Protein composition also varied among the extracts with differences in kafirin composition and non-kafirin proteins detected in the fractions by RP-HPLC and SDS-PAGE analysis. The ability to quantify and further characterize sorghum polymeric protein complexes will be useful for additional studies linking protein structures with functionality and digestibility and variations for these properties within diverse sorghum germplasm. 相似文献
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种质资源是遗传研究与作物改良的基础。饲草产量与品质是决定饲草型小黑麦品种利用价值的重要指标。本研究以113份国内外小黑麦种质为材料,通过2年田间种植,对其饲草产量与品质性状进行了分析与评价。结果表明参试小黑麦种质的饲草产量及其品质性状存在极显著差异,其单株鲜草产量分别为36.000~111.560 g与36.310~159.780 g,单株干草产量分别为12.000~27.000 g与9.150~30.150 g,鲜干比分别为2.380~4.370与2.610~6.210,饲草粗蛋白含量分别为6.894%~13.259%与6.680%~14.304%,饲草中性洗涤纤维含量分别为48.480%~74.850%与53.850%~67.980%,酸性洗涤纤维含量分别为26.600%~42.780%与29.000%~39.280%,饲草的相对饲用价值分别为69.650~128.150与79.840~113.170。饲草产量与品质性状的多样性指数范围为1.974~2.075。主成分分析表明,饲草纤维品质因子、饲草产量因子与综合品质因子为前3个主成分,其累计贡献率为82.198%。依据单株干草产量... 相似文献
96.
蔗糖转化酶家族基因进化、表达及对草莓果实糖分积累的影响 总被引:1,自引:0,他引:1
在草莓蔗糖碱性/中性转化酶家族基因(Fa.A/N-Inv)成员序列分析的基础上,以‘申阳’和‘红颜’草莓为材料,利用实时定量PCR技术分析了Fa.A/N-Inv家族基因在不同条件下的表达模式,利用分光光度法测定了果实发育过程中A/N-Inv酶活性,利用高效液相色谱法分析了果实发育阶段糖分积累规律。结果表明:(1)Fa.A/N-Inv是由8个成员组成的多基因家族;(2)4个Fa.A/N-Invs不仅具有组织特异性,还具有果实发育阶段特异性和品种特异性表达特点;(3)4个Fa.A/N-Invs的表达受细胞分裂素(BA)、赤霉素(GA)和生长素(IAA)诱导;(4)蔗糖和葡萄糖作为A/N-Inv酶促反应的底物和产物,分别对4个Fa.A/N-Invs转录表达起正、负反馈调节作用,此外蔗糖还可作为一种信号分子诱导Fa.A/N-Invs表达;(5)‘申阳’草莓A/N-Inv酶活性在绿果阶段低于‘红颜’,其余阶段均高于‘红颜’;(6)成熟果实中蔗糖含量‘红颜’(50.7 mg·g~(-1) FW)约为‘申阳’(23.2 mg·g~(-1) FW)的2倍。 相似文献
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98.
中国耕地非农化现象日益明显。基于社会燃烧理论分析了耕地非农化的驱动原理,建立了耕地非农化影响机制模型,并运用SPSS 19.0软件对分类驱动因素进行了主成分及回归分析。结果表明,人均GDP和固定资产投资所占GDP比重等经济发展变量对耕地非农化水平的正向影响最大;粮食单产、总产等农业技术变量对耕地非农化水平具有最大的逆向影响。最后在模型拟合的基础上提出了相应的对策与建议,旨在为合理有效保护耕地提供参考。 相似文献
99.
《Communications in Soil Science and Plant Analysis》2012,43(11-12):1487-1501
Abstract Sequential extraction techniques have been used to make inferences about speciation of phosphorus (P) and to a lesser extent arsenic (As) in soils. However, sequential extraction studies on the less‐abundant group V element, antimony (Sb), are limited. In this work, a widely used P sequential extraction scheme was modified and used to extract P, As, and Sb from two acidic soils from the Macleay River floodplain, NSW, that were enriched with Sb (26.9 and 23.0 mg kg?1). An ammonium oxalate–oxalic acid step was included in the extraction sequence to dissolve the noncrystalline iron (Fe) and aluminium (Al) hydroxide phase. It extracted 30 to 47% of Sb, indicating the importance of this fraction, which may be mobilized in the floodplain by acid sulfate soil processes and periodic waterlogging. The original method overestimated P, As, and Sb in the residual fraction (30–71%). Relative efficiency values of extracts for P, As, and Sb were compared, and inferences about phase distributions were made. The results suggest some potential in using extractions to assess bioavailability of Sb in soil. 相似文献
100.
《Communications in Soil Science and Plant Analysis》2012,43(19):2330-2339
This study evaluates the effect of soil particle size (SPS) on the measurement of exchangeable sodium (Na) (EXC-Na) by near-infrared reflectance (NIR) spectroscopy. Three hundred thirty-two (n = 332) top soil samples (0–10 cm) were taken from different locations across Uruguay, analyzed by EXC-Na using emission spectrometry, and scanned in reflectance using a NIR spectrophotometer (1100–2500 nm). Partial least squares (PLS) and principal component regression (PCR) models between reference chemical data and NIR data were developed using cross validation (leaving one out). The coefficient of determination in calibration (R2) and the root mean square of the standard error of cross validation (RMSECV) for EXC-Na concentration were 0.44 (RMSECV: 0.12 mg kg–1) for soil with small particle size (SPS-0.053) and 0.77 (RMSECV: 0.09 mg kg–1) for soils with particle sizes greater than 0.212 mm (SPS-0.212), using the NIR region after second derivative as mathematical transformation. The R2 and RMSECV for EXC-Na concentration using PCR were 0.54 (RMSECV: 0.07 mg kg–1) and 0.80 (RMSECV: 0.03 mg kg–1) for SPS-0.053 and SPS-0.212 samples, respectively. 相似文献