Polymorphism of IGFBP2 Gene and Its Association with Meat Quality Traits in Pigs

This study was aimed to analyze the genetic variation of insulin-like growth factor binding protein 2 (IGFBP2) gene effect on meat quality traits in pigs. A pair of primer was designed,which based on DNA sequence of IGFBP2 gene (GenBank accession No.:BV727778). The genetic polymorphism of IGFBP2 gene was detected by PCR-RFLP in Sujiang pig, Jiangquhai pig and Landrace pig, and the association between IGFBP2 gene polymorphism and meat quality traits in three pig breeds was analyzed. The results showed that three genotypes (AA, AB and BB) were detected. The Chi-square test results showed that the genotype distribution of three pig breeds was in Hardy-Weinberg equilibrium (P > 0.05). The polymorphism information content (PIC) were moderately polymorphic in three pig breeds. According to the association analysis of different genotypes, significant difference was found in color value, intramuscular fat content and marbling, the color value (except for Jianquhai pig) and intramuscular fat content of AA genotype were significantly higher than AB and BB genotypes (P < 0.05), the marbling of AA and AB genotypes was significantly higher than BB genotype (P < 0.05). In conclusion,the polymorphism of IGFBP2 gene intron 3 had significant effects on meat quality traits, and was candidate gene for the potential impact on meat quality traits of pigs.     

5种花梨木的红外光谱比较分析

为了提供识别花梨木品种的新思路和新方法,采用红外光谱分析方法,对越柬紫檀、刺猬紫檀、印度紫檀、大果紫檀、鸟足紫檀5种花梨木的一维红外光谱(FTIR)、二阶导数光谱(SDIR)、二维相关红外光谱(2DIR)进行对比分析。结果表明:1)在FTIR谱图中,5种花梨木在781 cm-1处的差异可以把越柬紫檀和刺猬紫檀与其他3种花梨木区分开;2)在SDIR 谱图中,刺猬紫檀在1 179 cm-1处存在1个吸收峰;大果紫檀在781 cm-1处存在吸收峰;鸟足紫檀在1 351、1 299、1 147、1 131、938 cm-1处都有明显的吸收峰,而印度紫檀没有吸收峰;3)在2DIR谱图中,1 100、1 150、1 258 cm-1处的差异可以将刺猬紫檀与其他4种花梨木区分开,1 467、1 518 cm-1处的差异可以把越柬紫檀、刺猬紫檀与鸟足紫檀区分开来。单独使用2DIR识别方法并不能把5种花梨木完全区分,但将FTIR、SDIR、2DIR这3种方法结合可以实现5种花梨木的区分,也有助于红木树种的无损识别。      

小鼠感染肝片吸虫早期IL-4/IFN-γ及M2巨噬细胞标记分子的变化

为弄清肝片吸虫感染早期的主要细胞免疫类型及选择性激活巨噬细胞(M2或AAMΦ)标记分子的变化,本试验采用肝片吸虫囊蚴为感染源,经口分别感染雌性BALB/c野生型小鼠,运用特异性PCR鉴定成功感染小鼠后用间接ELISA对腹腔中IL-4和IFN-γ的水平进行测定,并对细胞因子IL-4、转录因子GATA3和M2的标记蛋白Relm a、Ym1分子的mRNA进行荧光定量PCR检测.结果显示,在感染后1,3,5,7周,从所获取肝脏组织中扩增的ITS2片段条带清晰,大小正确,测序后确定为肝片吸虫ITS2序列,表明肝片吸虫感染成功.对腹腔中IL-4和IFN-γ的水平测定表明感染组IL-4在感染后1,3,5周比对照组的显著增加(P=0.013,P＜0.01,P=0.02),但在第7周时无显著差异.IL-4的水平显著高于IFN-γ(P=0.011),而在第7周两者间无显著差异；对腹腔中IL-4、GATA3、Relm α和Ym1 mRNA水平的测定结果表明,感染后IL-4和GATA3 mRNA水平在第3周达到最高峰；于感染后1,3,5,7周,IL-4和GATA3 mRNA水平都分别显著高于对照组(IL4:P=0.01,P=0.012,P=0.023,P=0.014;GATA3:P=0.011,P＜0.01,P=0.032,P=0.014),但IL-4和GATA3间无显著差异；Relm α和Ym1mRNA水平都分别显著高于对照组(Relm α:P＜0.01,P＜0.01,P＜0.01,P=0.011;Ym1:P＜0.01,P＜0.01,P＜0.01,P=0.012),且二者间无显著差异,并随时间推移mRNA水平都呈下降趋势,于第7周达到最低水平.本研究成功利用肝片吸虫-小鼠模型研究蠕虫感染早期细胞免疫类型及M2标记分子的变化,发现在肝片吸虫感染小鼠早期主要引起Th2为主的细胞免疫.IL-4和M2巨噬细胞标记分子Relm α和Ym1在感染后1,3,5,7周都显著增加且具有相似的变化趋势,但nelmα和Ym1在第1周的高表达可能受诸多因素的影响还有待深入研究.     

不同香型烤烟CO_2膨胀前后品质的比较研究

[目的]比较不同香型烤烟CO2膨胀前后品质变化。[方法]开展了3种主要香型烟叶CO2膨胀试验,对各样品烟丝膨胀前后的物理性能、化学成分、烟气指标和内在质量进行检测分析。[结果]清香型烟叶经过CO2膨胀,还原糖、挥发酸、焦油和烟碱含量平均降幅最大,香气质、香气量和柔细度改善或保持最佳;浓香型烟叶的平均膨胀效果最明显,总糖、总氮含量平均变化最大,杂气、刺激性、透发性和浓度改善或保持最佳;中间香型烟叶CO2膨胀后总植物碱、氯和蛋白质含量平均变化明显,重量、口数、总粒相物以及CO 4项指标降幅最大,甜度、余味指标有更好提升。[结论]不同香型烤烟各项理化、感官指标受膨胀影响程度有所差别,烤烟香型与CO2膨胀具有一定的关联性。     

肉桂挥发油的提取与应用研究

以肉桂为材料,采用水蒸气蒸馏法提取肉桂挥发油,并对其挥发油的主要应用进行研究,分别考察了蒸馏时间和加水量两种因素对挥发油提取率的影响。并通过实验证明肉桂挥发油对大肠杆菌具有抑菌作用。     

基于2D DWT与MobileNetV3融合的轻量级茶叶病害识别

针对现有茶叶病害识别方法病害信息挖掘不足导致识别准确率低的问题，该研究提出了一种基于二维离散小波变换(discrete wavelet transform, DWT)和MobileNetV3融合的茶叶病害识别模型CBAM-TealeafNet。为增强网络对病害频域特征的检测能力，将2D DWT获取的频域特征与bneck结构提取的深度特征融合，形成频域与深度特征融合的识别网络。为提高特征提取能力，在bneck结构中，嵌入卷积块注意模块 (convolutional block attention module, CBAM)，为特征通道分配相应权重。为解决样本类别不平衡对识别模型性能的影响，利用焦点损失函数取代交叉熵损失函数以提高识别精度。经验证，CBAM-TealeafNet在5种不同茶叶病害上整体识别准确率达到98.70%，参数量为3.16×10⁶，相对MobileNetV3，准确率提升2.15个百分点，参数量降低25.12%。该方法可为茶树叶部等作物病害轻量级识别研究提供模型参考。     

Physical activation of biochar and its meaning for soil fertility and nutrient leaching – a greenhouse experiment

The slow alteration of the surface of charred biomass (biochar) over time may contribute to an improved nutrient retention and thus fertility of tropical soils. Here, we investigated soils from temperate climates and investigated whether a technical steam activation of biochar could accelerate its positive effects on nutrient retention and uptake by plants relative to nonactivated biochar. To this aim, we performed microcosm experiments with sandy or silty soil, mixed with 2.0, 7.5 and 15.0 g/kg soil of fine (<2 mm) or coarse‐sized (2–10 mm) biochar from beech wood (Fagus sp.). After initial fertilizer (NPK), ashes and excess nutrients were leached with water, and the microcosms were planted for 142 days with Italian Ryegrass (Lolium multiflorum ssp. italicum). Thereafter, leachate, soil and plant samples were analysed for their nutrient contents. The results showed that biochar additions of ≤15 g/kg soil left elevated contents of available P and N in the surface soil but reduced their uptake into the plants. As a result, total biomass production was unchanged. Different particle size and application amounts influenced these findings only marginally. Nitrate leaching was enhanced in the sandy soil (+41% for nitrate, but reduced in the silty soil ?17%) and P was immobilized. Hence, the fertility of the temperate soils under study was only marginally affected by pure biochar amendments. Steam activation, however, almost doubled the positive effects of biochars in all instances, thus being an interesting option for future biochar applications.     

Genetic Variability in Phosphorus Acquisition and Utilization Efficiency from Sparingly Soluble P-Sources by Brassica Cultivars under P-Stress Environment

Plants display an array of classical strategies to maximize phosphate (Pi) acquisition from sparingly soluble P sources. Acclimation to Pi-stress via elegant Pi-starvation induced (PSI) adjustments would reduce our current overreliance on expensive, polluting and non-renewable Pi-fertilizers. Nevertheless, differences in the ability of various species to solubilize sparingly soluble P-sources have been often evidenced; inter-cultivar variations are scarcely documented. Brassica is known as an effective, non-mycorrhizal user of sparingly soluble P-sources. Various growth parameters and biomass accumulation by genetically diverse Brassica cultivars were determined in four experiments using hydroponics and quartz sand culture media. Role of PSI root mediated pH changes, organic anions (OAs) exudation and altered root architecture in mobilization and acquisition of sparingly soluble P-forms [Jordan rock-P (RP) at 2 g l⁻¹ and Ca₃(PO₄)₂ (TCP) at 0.2 g l⁻¹ respectively] was investigated. Cultivars showed considerable genetic variations in biomass accumulation, various growth parameters and root–shoot ratio. Concentration and total uptake of P, specific absorption rate of P, P-transport rate and P-utilization efficiency (PUE) were also significantly (P < 0.001) different for various cultivars and their dry matter was significantly correlated with P-uptake [r = 0.94** (significant at 1% level)]. P-tolerant cultivars showed substantial decrease in solution media pH because of H⁺ efflux and exuded more carboxylates than low P-sensitive cultivars under P-starvation. P-uptake by cultivars increased linearly with decreasing pH. The amount and types of OAs exuded from the roots of P-starved plants differed from those of plants grown under P-sufficient environment. In split pot study, with TCP and RP supplied spatially separated from other nutrients, efficient cultivars were still able to mobilize RP and TCP more efficiently than inefficient cultivars. In rhizobox study, the elongation rates of primary roots decreased but the elongation rates of the branched zones of primary roots and the length of lateral roots increased under P-starvation. Tested cultivars showed genetic diversity in accessing, mobilization, acquisition and utilization of Pi from sparingly soluble P forms. An arrange marriage of plant traits can explain cultivar’s access to different forms of sparingly soluble P, and in addition to altered lateral root topology and enhanced P-uptake and PUE, enhanced H⁺ efflux and OAs exudation are key factors in Pi scavenging from extra cellular sparingly soluble P-forms.