不同因子对梨多酚氧化酶活性的影响

对控制梨多酚氧化酶(PPO)活性的方法进行了研究,以氯化钠、柠檬酸、抗坏血酸为PPO活性抑制因子,通过三因子二次回归组合设计建立回归方程,从而准确地反映因子和PPO活性之间的关系,预示抑制因子用量的多少对PPO活性的影响程度和趋势,得出三个因子在抑制酶活性作用中的最佳配比,并分析了各因子间的交互效应.     

锈菌区系研究的历史与现状

对北美、欧洲、亚洲和中国的锈菌区系研究历史与现状作了全面评述,并将我国锈菌多样性研究划分为3个阶段.     

堆放时间对氨化麦秸含氮量的影响

按照麦秸∶水∶尿素比例100∶30∶4制作的氨化饲料,用凯氏定氮法测定含氮量。Ⅰ、Ⅱ号料含氮量分别为1．1317％、1．3718％,比麦草提高161．91％、217．55％。两种料经过1～130d室内堆放,分4个阶段测定,Ⅰ号料1～40d全氮损失9．89％,占全期全氮损失15．81％的62．6％;Ⅱ号料41～60d全氮损失8．13％,20d占全期全氮损失2985％的26．35％,均属损失高峰期。结果表明,氨化料应密封保存;麦秸粉碎比铡草制作的氨化料提高含氮量21.22％。     

植物工厂立体栽培系统多功能作业平台优化与试验

植物工厂中多采用立体栽培架进行育苗与栽培,立体栽培架上的栽培床搬运是其中重要一环.目前,栽培床多为人工搬运,存在劳动强度大、自动化水平低等问题.针对此问题,该研究研制了一种多功能作业平台,可实现自主循迹、定位和栽培床的自动搬运和输送.根据栽培床质量和立体栽培架高度要求,设计了升降机构,并确定了关键参数;研究了栽培床自动...     

Changes in the gut microbiome of the Chinese mitten crab (Eriocheir sinensis) in response to White spot syndrome virus (WSSV) infection

Intestinal microorganisms play important roles in maintaining host health, but their functions in aquatic animal hosts have yet to be fully elucidated. The Chinese mitten crab, Eriocheir sinensis, is one such example. We attempted to identify the shift of gut microbiota that occurred in response to infection of white spot syndrome virus (WSSV), an emerging viral pathogen in the crab aquaculture industry. The microbiota may exert some control over aspects of the viral pathogenesis. We investigated the changes in composition and structure of the crab gut microbiome during various WSSV infection stages of 6 h post‐infection (hpi) and 48 hpi, using a 16S rRNA approach on the MiSeq Illumina sequencing platform. Four phyla (Firmicutes, Proteobacteria, Tenericutes and Bacteroidetes) were most dominant in the gut of E. sinensis regardless of the WSSV infection stages. However, further analysis revealed that over 12 bacterial phyla, 44 orders and 68 families were significantly different in abundance at various states of WSSV infection. Several intriguing aspects of E. sinensis gut bacteria that had not been previously reported were also uncovered, such as class Mollicutes was dominant here, but absent in crabs from Yangtze River estuary and Chongming Islands. Overall, this study provided the first evidence that changes in gut microbiome were closely associated with the severity of WSSV infection and that indicator taxa could be used to evaluate the crab health status.     

Mixograph Responses of Gluten and Gluten‐Fortified Flour for Gluten Produced by Cold‐Ethanol or Water Displacement of Starch from Wheat Flour

The total protein of gluten obtained by the cold‐ethanol displacement of starch from developed wheat flour dough matches that made by water displacement, but functional properties revealed by mixing are altered. This report characterizes mixing properties in a 10‐g mixograph for cold‐ethanol‐processed wheat gluten concentrates (CE‐gluten) and those for the water‐process concentrates (W‐gluten). Gluten concentrates were produced at a laboratory scale using batter‐like technology: development with water as a batter, dispersion with the displacement fluid, and screening. The displacing fluid was water for W‐gluten and cold ethanol (≥70% vol, ‐12°C) for CE‐gluten. Both gluten types were freeze‐dried at ‐10°C and then milled. Mixograms were obtained for 1) straight gluten concentrates hydrated to absorptions of 123–234%, or 2) gluten blended with a low protein (9.2% protein) soft wheat flour to obtain up to 16.2% total protein. The mixograms for gluten or gluten‐fortified flour were qualitatively and quantitatively distinguishable. We found differences in the mixogram parameters that would lead to the conclusion of greater stability and strength for CE‐gluten than for W‐Gluten. Differences between the mixograms for these gluten types could be markedly exaggerated by increasing the amount of water to the 167–234% range. Mixograms for evaluation of gluten have not been previously reported in this hydration range. Mixograms for fortification suggest that less CE‐gluten than W‐gluten would be required for the same effect.     

饲料中添加不同类型核苷酸对凡纳滨对虾生长性能的影响

以1种对照饲料和3种分别添加200mg/kg鸟苷酸（5′-GMP）、腺苷酸（5′-AMP）和尿苷酸（5′-UMP）的试验饲料饲养平均体重为1.04±0.02g的凡纳滨对虾8周,研究不同类型核苷酸对凡纳滨对虾生长性能及体成分组成的影响。试验结果显示,四组试验虾的增重率组间差异不显著（P〉0.05）;AMP组的存活率显著高于UMP组（P〈0.05）,各添加核苷酸组与对照组之间无显著差异;各组的饲料系数差异不显著（P〉0.05）;各组虾全虾的水分、粗蛋白、粗脂肪及灰分含量均没有显著差异,其中添加核苷酸各组的粗蛋白及粗脂肪含量均高于对照组。     

水肥耦合对基质栽培番茄产量及品质的影响

为有效提高农业废弃物的利用率,将堆肥、秸秆等农业废弃物和黏土等拌制成一种抗旱促根的基质,研究水肥耦合效应对"爱吉3041"供试基质栽培番茄的株高、茎粗、产量、品质、水分利用效率(Water Use Efficiency,WUE)及肥料偏生产力(Partial Factor Productivity of Fertili...     

猪繁殖障碍性主要传染病的血清流行病学研究

对采自云南省楚雄州10县市22个规模猪场及107户农户的803份猪血清、642份临床无异常的种猪抗凝全血、84头繁殖障碍母猪血清及4头乳猪脏器,应用胶乳凝集试验(LAT)、猪伪狂犬病gE抗体鉴别酶联免疫吸咐试验(ELISA)、多方法酶联免疫吸咐试验、虎红平板凝集试验及试管凝集试验、间接血凝试验(HIA)、细菌学检验、流行病学调查等方法,对PR、PPV、PRRS、PCV-2、CSF、JE、布病、衣原体病共8种病同步进行血清学(猪瘟病原学)调查,结果感染率分别为30.39%、21.05%、3.11%、59.40%、1.71%、24.53%、0.25%和10.71%。流行病学调查结果,繁殖障碍发病场占调查场的68.18%,各场母猪繁殖障碍发病率在75.00%-0之间,农户散养母猪在20.00%-0之间。     

冬小麦品种‘兰天23号’苗期抗条锈性遗传分析

2014年在甘肃省农业科学院植物保护研究所兰州温室,进行了‘兰天23号’/‘铭贤169’组合的亲本及其F1、F2、BC1代对条锈菌主要流行小种CYR32、CYR33及新菌系G22-9的遗传分析。结果表明,接种CYR33,F2代植株抗感分离比为144R∶54S,符合3R∶1S的理论比值;接种CYR32,F2代植株抗感分离比为62R∶22S,符合3R∶1S的理论比值;接种G22-9,F2代植株抗感分离比为85R∶24S,符合3R∶1S的理论比值;F1代植株对供试菌系均表现免疫,BC1代植株抗感分离比均符合1R∶1S的理论比值,表明‘兰天23号’对3个供试条锈菌系的抗病性均由1对显性抗性基因控制。通过系谱分析推知,该抗病基因来源于抗病亲本‘SXAF4-7’。