Repellent and Fumigant Effects of Essential Oil from Clove Buds Syzygium aromaticum L. against Tribofium castaneum （Herbest） （Coleoptera： Tenebrionidae）

Essential oil from clove buds Syzygium aromaticum L. Merr. ＆ Perry （Myrtaceae） was extracted using petroleum ether in Soxhlet apparatus. The resultant oil contained eugenol （48.92%）, caryophyllene （18.55%）, α-caryophyllene （3.25%）, eugenol acetate （23%）, cis-13-docosenamide （3.2 1%）, presenting more than 96% of the oil. This oil was examined as a fumigant and repellent agent against adults of the red flour beetle, Tribolium castaneum. Data showed that various concentrations of the oil have revealed dramatic repellent activity against the tested insect, where it gave 100% repellency by 1.0, 0.8, and 0.2% clove oil at 4, 8, 10 min, respectively. The RTs0 and RT95 were 1.1 and 8.0 min at 0.2% and 0.4, 2.6 min at 0.8%, respectively. In addition, fumigation assay has also exhibited strong fumigant activity toward the adults of T. castaneum. At 100 μL oil/L air, mortality was 75, 80 and 100% after 6, 7, and 8 days exposure period with LCs0 and LC95 17 and 70 μL/L air, respectively. The utilization of clove oil for its potential effects against stored product insect is discussed.     

Effects of Environmental Temperature on the Regeneration Frequency of the Immature Embryos of Wheat （Trificum aestivum L.）

The immature embryos （IEs） of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture （HSC） temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature （TAT） during the time of anthesis and sampling for regeneration of these tissues was around 280℃ for spring wheat type cv. CB037 and approximately 300℃ for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35℃ for 1 d or a high temperature between 30 and 33℃ lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37℃ in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37℃. Cryopreservation of-20℃ caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of-10℃ more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5℃, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10℃ inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.     

The Effects of Dwarfing Genes （Rht-B1b,Rht-D1b,and Rht8） with Different Sensitivity to GA3 on the Coleoptile Length and Plant Height of Wheat

Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.     

小麦面粉的微形态观察与分析

研究结果发现，面粉颗粒是由一个淀粉粒或多个由基质蛋白质粘合起来的淀粉粒构成，呈不规则形。基质蛋白质总是和淀粉粒粘合在一起，有类似建筑上的“桁架结构”。淀粉粒之间有一种类似“铆钉”的“球状蘑菇形”，将淀粉粒嵌合在一起，形成一种稳定结构，基质蛋白质仅是这种“桁架结构”中的“填充物”     

硫酰氟在仓储害虫防治中的应用研究

[目的]研究硫酰氟对贮烟害虫的熏杀效果。[方法]设置4个试验仓间,每个仓间均设置上中下3个浓度检测点。熏蒸过程前期每2h检查一次,共检查11次。[结果]硫酰氟熏蒸防治烟草害虫的研究表明,硫酰氟整仓熏蒸22h后,仓问设置的3个浓度监测点的浓度基本一致;均能达到对烟草甲成虫100％的杀灭效果。[结论]为进一步推广应用提供相关依据。     

甘肃省57个春小麦品种品质性状分析

筛选了甘肃省不同历史时期种植的57个春小麦品种,测定了其理化特性和面团流变学特性,分析了各品种品质性状的变异情况.结果表明:供试品种品质的差异反应在蛋白质的质量上而不是数量上,且大部分品种的面粉都属于弱筋粉;随着育种工作的推进,市场对优质品种的需求,小麦面粉的综合品质状况出现明显的改善,尤其自上世纪90年代以后大部分品种的面粉已达到中筋以上,其面团流变学特性也显示这此品种的面粉适合于加工北方口味的食品.     

HACCP在小麦粉生产中的应用研究

贯彻HACCP应用准则,应用HACCP原理,对小麦粉生产进行HACCP应用研究,确立了小麦接收、微量成分添加、磁选检测3个关键控制点及其关键限值、监控方法和纠正措施,提高了小麦粉生产的安全性和质量水平.     

不同品系糯小麦粉品质特性的差异

对26个糯小麦品系、8个非糯小麦品种和4个部分糯小麦品种的理化性质研究结果表明:糯小麦粉的降落值为64～77 8.远低于非糯小麦和部分糯小麦,各品系间差异较小;而吸水力较部分糯小麦和非糯小麦强,最高达73.5%,并具有较高的公差指数、较低的粉质质量指数、较短的形成时间和稳定时间,因此流变学特性较弱;总淀粉含最与非糯小麦及部分糯小麦没有显著差异,表明糯质突变没有影响到籽粒中总淀粉含量;糯小麦的糊化温度和峰值温度分别介于60.7～63.6℃和67.3～72.6℃之间,都低于部分糯小麦和非糯小麦;还具有高崩解值、低峰值黏度和回生值.此外,糯小麦粉的降落值与α-淀粉酶活性不存在相关关系.     

添加剂及酶制剂在小麦粉中应用知识

我国食品专用粉的生产目前还处于刚刚起步阶段，在质量指标中真正涉及小麦本身品质的只有湿面筋含量，而对影响面制食品质量更为主要的面筋质量和面团流变学特性未作任何规定。由于通用小麦粉难于加工出各种不同品质要求的面食制品，因此发展食品专用粉势在必行。着重讨论小麦专用粉中所使用的添加剂及酶制剂特性及作用。     

小麦面粉粘度特性与面条品质关系的研究

以参加陕西省区域试验的 18个小麦品种 (品系 )为材料 ,系统研究了小麦面粉的粘度特性、淀粉酶活性及其与面条品质性状间的关系。结果表明 ,峰值粘度、起始恒温糊化阻力、起始降温糊化阻力、冷却结束糊化阻力、破损值、回生值及降落数值在小麦品种间变化较大 ,α-淀粉酶活性对小麦面粉的糊化有很大影响 ,面粉粘度特性指标峰值粘度、起始恒温糊化阻力及破损值是预测面条品质的重要指标     

小麦品种面粉粘度性状及其在面条品质评价中的作用

研究了４１个小麦品种面粉的快速粘度仪参数及其与面条品质的关系。结果表明,几项面粉粘度性状如高峰粘度、低谷粘度和最后粘度等分别与面条评分间呈０．００１水平显著正相关;建立了面条评分依高峰粘度的回归方程;讨论了小麦品种面条品质的预测指标等问题。为小麦杂交育种早期世代根据高峰粘度等若干粘度性状对面条品质的筛选提供了理论依据。     

小麦粉面包烘烤品质指标的研究——Ⅵ评价值受控因子的多元分析

测定了在河南种植的50个小麦品种(系)的9项粉质仪指标,借助于多元分析方法,建立了一组有关粉质性状对评价值的回归方程。探讨了评价值受控因子规律,并应用主成分回归分析在损失少量信息的情况下,拟合了更具有实践意义的回归方程。