茉莉酸甲酯对重瓣玫瑰抗虫生理指标和双斑萤叶甲取食的影响

喷施不同浓度的茉莉酸甲酯(Me JA),研究其对重瓣玫瑰(Rosa rugosa‘Plena’)抗虫生理指标和双斑萤叶甲(Monolepta hieroglyphica(Motschulsky))取食的影响。结果表明:不同浓度的Me JA处理对重瓣玫瑰过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性及缩合单宁、总酚质量分数影响明显,能不同程度减少双斑萤叶甲取食叶面积。0.5 mmol·L-1Me JA在第1、3、5、7天诱导的POD活性显著高于其他浓度诱导的;0.5mmol·L-1Me JA诱导了较高的PPO活性,在第3、5天诱导的PPO活性显著高于其他浓度诱导的;1.0 mmol·L-1的Me JA诱导了较高的PAL活性,在第1、3、5、7、9天诱导的PAL活性显著高于其他浓度诱导的;1.0 mmol·L-1Me JA在第1、3、5、7、9天诱导的缩合单宁质量分数显著高于其他浓度诱导的;1.0 mmol·L-1Me JA诱导的总酚质量分数在第3、7、9天显著高于其他浓度诱导的。双斑萤叶甲取食0.5、1.0 mmol·L-1Me JA诱导的叶片面积在实验期间均极显著低于对照。Me JA诱导重瓣玫瑰抵御双斑萤叶甲取食的适宜浓度为0.5、1.0 mmol·L-1。     

烟草中关键致香物质积累、降解及其对品质影响的研究进展

烟草中的关键致香物质主要源自类胡萝卜素、叶绿素、西柏烷类、苯丙氨酸类、赖百当类的降解和美拉德反应。为烟草加工、调香及致香物质的研究提供参考,总结了烟草中关键致香物质的积累、降解规律及其对卷烟品质的影响。     

地方院校研究生综合素质提升途径研究与实践

目前研究生教育中存在着重视专业素质而忽视人文素质、重视传授而忽视创新素质、急功近利而忽视思想素质、理想主义而忽视身体和心理素质等问题。为了全方位提升研究生的培养质量,以沈阳农业大学为例,围绕思想道德教育、学术能力、职业能力、人文素质、身心素质和实践能力培养等方面搭建各类平台,实现研究生素质提升的"量体裁衣",进而达到事半功倍的效果。     

闽北米槠天然林群落乔木层多样性分析

该研究通过对米槠天然次生林的样地调查,计算其多样性指数,对乔木层物种数量特征、径级分布、高度级分布进行分析,并比较了不同样地间的树种多样性。结果表明:米槠占据顺昌县米槠天然次生林群落优势地位,其径级分布符合一般天然林径级分布规律,其乔木层树种与株数随径级的增加而降低,林分中主要树种分布于中间高度级4~8m,群落物种均匀度指数、多样性指数和生态优势度指数分别为0.67、1.70和0.39,天然次生林群落整体处于稳定演替阶段。     

船舶压载水浮游植物采样技术的比较

通过模拟实验,比较了夏季和冬季2个季节条件下4种采样方法(采水器法、隔膜泵法、潜水泵法和管道法)和4种采样体积(1 L、10 L、100 L和1 000 L)对船舶压载水浮游植物采样效果的影响。夏季4种采样方法采集到的浮游植物密度分别为1 180.00±20、971.00±20、964.00±20和676.00±20 cells/L,冬季为152.00±20、120.00±20、80.00±20和200.00±20 cells/L。夏季4种采样体积下采集到的浮游植物密度为1 000.00±50、288.40±20、45.24±10和0.05±0.01 cells/L,冬季为168.00±20、25.20±10、3.32±1和0.05±0.01 cells/L。结果显示不论夏季还是冬季,不同的采样方法和采样体积下采集到的船舶压载水浮游植物数量差异显著,因而采样方法和采样体积影响着船舶压载水浮游植物的采样效果,亟需在国际层面推动通过系统的科学研究,建立起统一准确的船舶压载水采样方法,为压载水港口国检测提供技术支撑,保护港口和海洋生态环境。     

Enhanced immune responses and effectiveness of refined outer membrane protein vaccines against Vibrio harveyi in orange‐spotted grouper (Epinephelus coioides)

Vibriosis is a severe infection occurring in many commercially important marine fish species. In this study, vaccines containing Vibrio harveyi recombinant outer membrane protein K (rOmpK), outer membrane protein U (rOmpU) and rOmpK‐OmpU fusion protein in addition to the metabolizable Montanide^TM ISA 763 A VG adjuvant were developed and evaluated in the orange‐spotted grouper. The results indicate that recombinant V. harveyi protein‐based vaccines resulted in a remarkably higher expression of IL‐1β and IL‐8 at 24 hr, and greater antibody production, as early as 2 weeks postimmunization. Notably, enhanced immune responses and significant protective efficacy against V. harveyi infections were observed in the fusion protein vaccine‐injected fishes with relative per cent survival value of 81.8%. Additionally, the rOmpK‐OmpU antisera presented a high bactericidal effect on not only V. harveyi, but also Vibrio parahaermolyticus and Vibrio alginolyticus. Our results demonstrated that the fusion protein rOmpK‐OmpU was an effective vaccine candidate that exhibited potentially great versatility for controlling vibrio infections.     

Immune Response and Disease Resistance of Barramundi,Lates calcarifer (Bloch), Offered Diets Supplemented with Replete Levels of Tryptophan or Whey

A basal diet containing 45% protein, 10% lipid, and 1.95% tryptophan (Trp) was formulated, and then supplemented with crystalline Trp (0, 0.1, 0.5, and 1% of the diet) or whey (16.9%) to evaluate the physiological effects of juvenile (initial weight: 0.57 ± 0.15 g) barramundi over a 58‐d rearing period. Significant reductions in growth and feed intake were observed in fish offered diets supplemented with Trp as compared to those offered the basal diet or the whey diet. Brain serotonin increased in fish fed the 1% Trp and whey diets albeit a decrease in cannibalism was not observed. Phagocytic activity, and Mx gene expression in spleens were not significantly changed among all groups. There were significant increases in lysozyme activity in the 1% Trp and whey groups, respiratory burst in the whey group, and Mx gene expression in head kidneys in the 1% Trp group 12 h after nerve necrosis virus (NNV) injection and in the whey 12 group and 24 h after NNV injection. Cumulative mortalities of fish fed the whey diet were significantly lower than those of fish fed the basal diet after Aeromonas hydrophila infection, but not Trp groups. Based on these results, diets supplemented with whey had reduced mortality when challenged with A. hydrophila and consequently function as an immunostimulant.     

Investigations on zinc bioavailability of different sources and dietary zinc requirement in juvenile grouper Epinephelus coioides

An experiment was implemented to study the effect of dietary zinc levels from three zinc sources on growth performance, immunity, and tissue mineral elements deposition on juvenile grouper. Based on the zinc free feeds, dietary zinc levels of 0, 10, 20, 40, 80, and 160 mg/kg were added from zinc sulphate (ZnSO₄), tetrabasic zinc chloride (TBZC), and 2‐hydroxy‐4‐(methylthio) butyrate zinc (Zn‐HMB). The results of the 8‐week study indicated that the weight gain rate (WGR) and specific growth rate (SGR) at level 10 mg/kg were significantly higher than the control fed and the reached a plateau until level 80 mg/kg, when the sources were ZnSO₄ and Zn‐HMB. WGR and SGR decreased significantly at level 160 mg/kg compared to 80 mg/kg in group TBZC. Feed coefficient (FCR) of all zinc source groups showed trend of decrease before rising. The alkaline phosphatase (AKP) in serum, catalase (CAT), total superoxide dismutase (SOD), copper‐zinc superoxide dismutase (Cu‐Zn SOD) in liver and zinc concentrations in whole body and vertebrae increased significantly than those in control group and then kept steadily in all treatments. Regardless of the sources, the manganic content of whole body or vertebra showed a downtrend. Based on the WGR, the dietary zinc requirements in juvenile grouper were 52.94 mg/kg from ZnSO₄. The average relative bioavailability (RBV) of TBZC and Zn‐HMB was 169.33% and 200.33%, respectively, compared to ZnSO₄.     

基于根点替代的猕猴桃果园行间导航线生成方法研究

针对棚架式猕猴桃果园树干分立、树干与树冠分离的生理特点,提出基于深度学习的目标检测框底边中点替代果树根点的导航特征目标检测方法。使用LabelImg标注预处理图像中的树干信息,生成猕猴桃树干数据集,基于Faster R-CNN构建目标检测模型,实现对猕猴桃果园行间有效范围的树干识别,利用根点替代方法确定树干根点的定位基点坐标,基于三次样条插值法提取树行线,根据最小二乘法拟合生成导航线。试验结果表明,生成的目标检测模型在地膜、杂草和土壤等果园行间环境下,树干正确识别率分别为90.6%、90.1%、89.4%;树干像素高度大于300像素、200～300像素、100～200像素的正确识别率分别为94.6%、89.9%、85.6%,表明选择树干作为果园行间视觉导航标识,有效利用了深度学习的稳定性,提高了导航目标识别的准确率;根点替代简化了导航定位基点生成算法,获取的果树定位基点与实际树干根点的平均横向像素误差占比为1.3%,平均纵向像素误差占比为2.2%,平均实际距离误差为0.102 m,导航定位基点精度较高;生成的导航线平均横向像素偏差为5.1像素,实际平均横向偏差为0.052 m,获取的果园行间导航路径满足行间导航要求。