小麦铁锌营养品质研究进展

"隐性饥饿",即铁、锌等微量元素缺乏症,已成为困扰我国居民的首要营养不良问题.选育高铁、锌含量、强植酸酶活性或低植酸含量的"微量营养强化型"小麦品种对于改善我国西部居民的营养状况具有重要的意义.本文主要介绍小麦铁锌营养品质的遗传改良研究进展,包括铁锌营养品质的相关化学组分(铁、锌、植酸和植酸酶)及改善小麦铁锌营养品质的遗传途径等两方面,并指出了小麦铁锌营养品质的研究方向和工作重点.     

水产品中生物胺的测定方法

用高效液相色谱法同时分离检测水产品中的多组分生物胺.这些生物胺包括：色胺,章鱼胺,2-苯乙胺,腐胺,尸胺,组胺,5-羟色胺,酪胺,亚精胺和精胺.高氯酸溶液提取,丹酰氯衍生,再用氨水去除尸胺干扰峰.C18反相色谱柱,用醋酸胺和乙腈为流动相,梯度洗脱,流速为1.0 mL/min,柱温40 ℃;254 nm下紫外检测器检测.结果表明：平均回收率是79.59%～111.10%;相对标准偏差为2.6%～15.8%;方法检测限（信噪比S/N=3）：腐胺、亚精胺0.8 μg/g;尸胺、组胺、酪胺、精胺1 μg/g;章鱼胺、5-羟色胺2 μg/g;2-苯乙胺3 μg/g;色胺5 μg/g.     

镧和精恶唑禾草灵对鲦红细胞微核及核异常的影响

鲦经过稀土元素镧和除草剂精恶唑禾草灵单独或联合作用24 h,结果表明:0.01~0.5 mg/L的La3 能显著抑制鲦红细胞微核及核异常的发生,不具遗传毒性;但当La3 质量浓度≥1 mg/L及精恶唑禾草灵均能明显诱导鲦红细胞微核及核异常的发生,与对照组相比,差异显著或极显著(P<0.05或P<0.01),具有遗传毒性。且精恶唑禾草灵质量浓度为0.01725~0.345 mg/L,微核率随浓度的增大而升高。0.01、0.1 mg/L的La3 与精恶唑禾草灵联合作用时的微核率明显低于精恶唑禾草灵而高于La3 单独作用时的微核率。而10 mg/L的La3 与精恶唑禾草灵联合作用时的微核率却明显低于二者单独作用时的微核率,二者呈拮抗作用;鲦是研究遗传毒理学的良好材料。     

氯化苄法提取植物内生放线菌基因组DNA

以植物内生放线菌菌株GL0806123为试材,用氯化苄快速提取植物内生放线菌菌株GL0806123基因组DNA。建立用氯化苄提取植物内生放线菌基因组DNA的方法。结果表明:用氯化苄法能够成功提取植物内生放线菌菌株GL0806123基因组DNA,以此为模板PCR扩增出16S rDNA区段,测序后可用于菌种鉴定。氯化苄法是一种快速提取植物内生放线菌基因组DNA的方法。     

Cotton maturity and responses to harvest aids following chemical topping with mepiquat chloride during bloom period

Early maturity, complete defoliation and boll opening are essential for the efficient machine harvesting of cotton. Chemical topping, involving one extra application of mepiquat chloride(MC) in addition to its traditional multipleapplication strategy, may be able to replace manual topping. However, it is not known whether this chemical topping technique will influence maturity or cotton responses to harvest aids. In this 2-yr field study, we determined the effects of the timing of chemical toppi...     

矮壮素对马铃薯磷素营养动态变化和产量的影响

通过对生育前期的马铃薯品种"中薯3号"喷施浓度为0、1.5、2.0和2.5g/L矮壮素(chlorocholine chloride,CCC)后,应用32P示踪技术研究其对磷素营养及其平均每穴产量的影响。结果表明:在各出苗后天数,CCC增加了植株对磷素的吸收,植株中的磷素主要分配到地上茎和叶中,按其相对含磷量依次为地上茎>叶>根>地下茎;植株吸磷量随其生长而增加,但在生育后期总株的吸磷量减少;在各出苗后天数,2.0g/L处理对中薯3号的总株吸磷量增加最大;1.5、2.0、2.5g/LCCC处理使中薯3号平均每穴产量分别增加6.83%、10.10%和3.08%,各处理平均每穴产量与其出苗后36d的叶片含磷量成极显著性正相关。     

丁香叶油及其与壳聚糖和CaCl2复配对砀山酥梨的保鲜效果

研究了砀山酥梨用丁香叶油及其与壳聚糖和CaCl2复配剂涂膜处理后低温冷藏(0℃~2℃)的保鲜效果。结果表明,丁香叶油及其与壳聚糖和CaCl2复配剂对砀山酥梨具有明显的保鲜作用,其中以DKLO2(40μl/L丁香叶油+1%壳聚糖+1%CaCl2)浸涂保鲜效果最好,可显著延缓砀山酥梨采后硬度和可溶性固形物的下降,可使呼吸高峰较对照推迟10d出现,并能显著抑制MDA含量的增加及相对电导率和PPO活性的上升;贮藏至第30天,SOD活性较对照增加95.61%,CAT和POD活性分别是对照的2.22及4.28倍。DKL02浸涂处理可使砀山酥梨的贮存期达7个月。     

The effect of sodium chloride on gluten network formation and rheology

Gluten samples were obtained from two wheat flours with different levels of total protein in the presence or absence of sodium chloride (2% flour base). The dynamic oscillation rheology, large extensional deformation, confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM) and chemical analysis of disulfide bond linkages and the ratio of polymeric glutenins and monomeric gliadins were used to investigate the effect of salt on the structure and rheological properties of gluten. CLSM and TEM images showed that NaCl caused the gluten to form fibrous structure. The presence of NaCl increased non-covalent interactions and β-sheet structure, measured by FTIR, in gluten proteins. The gluten matrix formed with salt resulted in higher tan δ values corresponding to a less elastic network when measured using oscillatory rheometry. Large deformation extensional measurements showed that the maximum force to fracture were lower for the gluten samples prepared in the presence of NaCl. The results from this study indicate that changes in the solvent quality due to the presence of NaCl during dough mixing result in different molecular conformation and network structure of gluten proteins which contributed to the differences in the rheological properties.     

紫外老化和热老化对农用薄膜性能影响的对比分析

[目的]研究老化行为是解决农用薄膜的老化现象、防止老化的基本手段.[方法]采用加速紫外老化和热老化2种方法,对老化前后聚氯乙烯（PVC）薄膜和高密度聚乙烯（HDPE）薄膜的拉伸性能、透气性能和透湿性能等进行对比分析.[结果]在2种老化方式下,HDPE薄膜的拉伸强度都下降,在老化120 h时,热老化拉伸强度降低6.07％,而紫外老化拉伸强度下降15.08％;PVC薄膜在老化120 h时,热老化拉伸强度上升33％,而紫外老化拉伸强度下降13.8％.在2种老化方式下,HDPE薄膜透气量都上升,老化120 h时,热老化透气量增加107.64％,而紫外老化透气量增加219.39％;PVC薄膜在达到最大透气量后缓慢降低.2种老化方式下,在老化120 h内,HDPE薄膜透湿量都是先降低后上升,而PVC薄膜透湿量都下降.[结论]该研究可以为合理使用农用塑料膜,降低老化的影响提供参考依据.