基于有机质特征谱段的土壤Cd含量高光谱遥感反演

针对土壤Cd高光谱遥感定量反演中的机理性不足及数据冗余问题,提出一种基于有机质特征谱段的反演方法。该方法首先提取土壤光谱中对重金属Cd具有吸附作用的有机质特征谱段,进而通过竞争性自适应重加权采样法（Competitive adaptive reweighted sampling,CARS）优选特征谱段,采用偏最小二乘回归法（Partial least squares regression,PLSR）建立重金属Cd的反演模型,并利用郴州矿区土壤实验室光谱数据和哈密黄山南矿区野外光谱数据进行方法验证。研究表明：有机质特征谱段提取在降低数据冗余的同时提高了重金属Cd的反演精度,CARS算法相对于相关系数法（Correlation coefficient,CC）和遗传算法(Genetic algorithm,GA)特征选择具有更高的反演精度,基于有机质特征谱段的CARS-PLSR算法在土壤实验室光谱和野外实测光谱所得验证精度R2分别为0.94和0.80,表明该算法对于实验室和野外光谱均具有一定适用性。研究可为土壤重金属含量高光谱反演的特征波段选择和算法优选提供参考。     

贝莱斯芽胞杆菌ZF145抑菌物质提取方法比较及成分鉴定

为明确贝莱斯芽胞杆菌Bacillus velezensis菌株ZF145中可有效抑制黄瓜角斑病病原菌扁桃假单胞菌流泪致病变种Pseudomonas amygdali pv.lachrymans的主要物质,采用冻干法、酸沉法、絮凝法、萃取法和铵沉法提取菌株ZF145发酵液中的抑菌物质,通过室内盆栽试验验证粗提物对黄瓜角斑病的防治效果,综合比较不同方法的提取效果,并通过高效液相色谱-质谱（high performanceliquid chromatography-mass spectrometry,HPLC-MS）联用技术鉴定粗提物中的抑菌物质。结果表明,絮凝法最适用于贝莱斯芽胞杆菌菌株ZF145发酵上清液中抑菌物质的提取,通过絮凝法提取的粗提物对扁桃假单胞菌流泪致病变种的抑菌圈直径达到19.50 mm,对黄瓜角斑病的盆栽防治效果为42.85%,且粗提物中的主要抑菌物质为C₁₃~C₁₆的surfactin同系物,浓度和纯度均为最高,分别为2.77 g/L和69.28%。表明本研究优化的絮凝法可用于芽胞杆菌发酵液中抑菌物质的提取。     

大黄素甲醚、大黄酸的研究进展

2014年世界卫生组织首份全球抗菌素耐药报告显示全世界面临严重的公共卫生威胁,2021年农业农村部制定了《全国兽用抗菌药使用减量化行动方案》(2021-2025),从国家层面实施综合治理策略和措施,鼓励替代抗菌药物的研制和创新。大黄素甲醚、大黄酸作为植物蒽醌类有效成分,具有抗微生物、抗炎、抗氧化、神经保护等药理作用,但对其抗菌、抗病毒、抗炎症相关的作用机制和产业化工艺缺少详细报道。本文对国内外已经发表的专利文献、期刊文献进行综述,总结其抗菌、抗病毒、抗炎作用机制及其生产工艺,以期为进一步开发利用提供科学支撑。     

Discrimination of wild and hatchery trout by natural chronological patterns of elements and isotopes in otoliths using LA‐ICP‐MS

Abstract The potential to discriminate between wild and hatchery trout [Salmo trutta f. fario L. and Oncorhynchus mykiss (Walbaum)] by chronological microchemical patterns of different otolith regions was tested. Central and rim regions of otoliths were analysed for life stage specific elemental patterns of strontium (Sr), sodium (Na) and calcium (Ca) as well as of ⁸⁷Sr/⁸⁶Sr ratios using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS). Classification to life stage specific habitats was achieved with 100% accuracy by ⁸⁸Sr/⁴³Ca, ²³Na/⁴³Ca and ⁸⁷Sr/⁸⁶Sr ratios resulting in a discrimination of hatchery fish from wild fish. ⁸⁷Sr/⁸⁶Sr ratios and Sr concentration in otoliths were positively correlated with the ratio and amount in the water. Na content in otoliths did not directly reflect the concentration in the water, although the ²³Na/⁴³Ca ratio in otoliths contributed to the discrimination. Clear differences in otolith chemistry were found for fish experiencing different geological units or a groundwater‐fed environment in a hatchery. Natural chronological microchemical patterns in otoliths proved to be a valuable tool for discriminating wild and hatchery fish without the necessity to use marking methods. LA‐ICP‐MS is well suited for this application because of its limited need for sample preparation, its potentially high sample throughput and the possibility of simultaneous measurement of multiple elemental and isotopic fingerprints.     

Hygiene-Eliciting Brood Semiochemicals as a Tool for Assaying Honey Bee (Hymenoptera: Apidae) Colony Resistance to Varroa (Mesostigmata: Varroidae)

Despite numerous interventions, the ectoparasitic mite Varroa (Varroa destructor Anderson and Trueman [Mesostigmata: Varroidae]) and the pathogens it vectors remain a primary threat to honey bee (Apis mellifera Linnaeus [Hymenoptera: Apidae]) health. Hygienic behavior, the ability to detect, uncap, and remove unhealthy brood from the colony, has been bred for selectively for over two decades and continues to be a promising avenue for improved Varroa management. Although hygienic behavior is expressed more in Varroa-resistant colonies, hygiene does not always confer resistance to Varroa. Additionally, existing Varroa resistance selection methods trade efficacy for efficiency, because those achieving the highest levels of Varroa resistance can be time-consuming, and thus expensive and impractical for apicultural use. Here, we tested the hypothesis that hygienic response to a mixture of semiochemicals associated with Varroa-infested honey bee brood can serve as an improved tool for predicting colony-level Varroa resistance. In support of our hypothesis, we demonstrated that a mixture of the compounds (Z)-10-tritriacontene, (Z)-8-hentriacontene, (Z)-8-heptadecene, and (Z)-6-pentadecene triggers hygienic behavior in a two-hour assay, and that high-performing colonies (hygienic response to ≥60% of treated cells) have significantly lower Varroa infestations, remove significantly more introduced Varroa, and are significantly more likely to survive the winter compared to low-performing colonies (hygienic response to <60% of treated cells). We discuss the relative efficacy and efficiency of this assay for facilitating apiary management decisions and selection of Varroa-resistant honey bees, as well as the relevance of these findings to honey bee health, pollination services, and social insect communication.     

忍冬花蕾的化学成分研究

采用硅胶柱层析、反相硅胶(ODS)柱层析,从忍冬花蕾乙醇提取物的乙酸乙酯萃取部分分离得到9个化合物,经理化常数对照及波谱分析,鉴定它们的结构分别为环烯醚萜苷类:马钱子素(1), 獐牙菜苷(2),7-epi-vogeloside (3),7-epi-loganin(4),secoxyloganin(5);有机酸类:咖啡酸(6),对 -羟基苯甲酸(7);植物甾醇类:β-谷甾醇(8),胡萝卜苷(9).化合物4、5、6、7为首次从忍冬花蕾中分离得到.经初步药理实验,发现化合物1、4、5具有保肝作用.     

香港牡蛎不同育肥方式的育肥效果

香港牡蛎营养丰富,味道鲜美,在上市前会通过集中育肥提高风味口感和经济价值。为探明不同育肥方式对香港牡蛎的育肥效果,对经过池塘育肥和外海育肥后香港牡蛎的壳高、壳长、壳宽、体质量、软体质量、出肉率、糖原含量、甜菜碱含量、蛋白含量等指标进行检测,并与内海对照组牡蛎进行比较分析。检测结果显示,经过池塘育肥,香港牡蛎的壳高、体质量、糖原含量和蛋白含量均显著升高( P <0.01),甜菜碱含量显著降低( P <0.01),壳长、壳宽、软体质量、出肉率无显著变化;经过外海育肥的香港牡蛎糖原含量显著升高( P <0.01),壳高、壳长、体质量、软体质量( P <0.01)和甜菜碱( P < 0.05 )含量显著降低,壳宽、出肉率和蛋白含量无显著变化。试验结果表明,池塘育肥比外海育肥效果要好;不论哪种育肥方式,育肥后牡蛎的糖原含量均显著升高,甜菜碱含量均显著降低,出肉率均无显著变化。     

马尾松种子发育过程中种仁贮藏物质的积累与变化

连续４ａ以不同发育阶段的马尾松种子为试材，研究其种仁贮藏物的积累过程及其组分含量的变化规律，结果表明，（１）种仁的干重占成熟球果干重的４．８％，其贮藏物质随种胚发育而不断变化，粗脂肪，粗蛋白和总糖的最终含量分别为４４．７６％，４２．５０％和７．１４％（其中淀粉和可溶性糖分别为４．２６％与２．８８％）。（２）酶蛋白的最大含量在原胚阶段初为２０．８３％，以后至幼胚阶段急剧减少到４．９％。（３）脂肪由４     

7种黄檀属植物心材挥发油的成分分析及其抗菌活性

为了研究7种黄檀属（Dalbergia L.）植物心材的挥发性成分及其抗菌活性,采用水蒸气蒸馏法提取黄檀属植物心材的挥发性成分,气相色谱-质谱联用技术（GC-MS）对其化学成分进行分析;采用滤纸片琼脂扩散法测定挥发性成分的抗菌活性。结果表明,两粤黄檀检出9种成分,占总含量的98.93%;斜叶黄檀检出6种成分,占总含量的91.80%;交趾黄檀检出13种成分,占总含量的86.23%;海南黄檀检出9种成分,占总含量的94.86%;降香黄檀检出8种成分,占总含量的97.38%;东京黄檀检出8种成分,占总含量的97.72%;白沙黄檀检出23种成分,占总含量的79.45%。两粤黄檀和斜叶黄檀相对百分含量最大的成分为榄香素,分别为83.38%和73.03%;交趾黄檀中相对百分含量最大的成分为美迪紫檀素,为27.72%;海南黄檀中相对百分含量最大的成分为亚油酸,为42.80%;降香黄檀和东京黄檀中相对百分含量最大的成分为(7R,10S)-2,6,10-三甲基-7,10-环氧-2,11-十二碳-6-醇及其同分异构体,二者之和分别为60.37%和53.23%;白沙黄檀中已鉴定出且相对百分含量较大的成分为榄香素,为7.81%。黄檀属植物心材挥发性成分主要有苯丙素类、倍半萜类、黄酮类、脂肪酸类和甾体等,黄檀属植物心材的挥发性成分均对金黄色葡萄球菌具有抑制作用,部分挥发油对不同的农业病原菌具有一定的抑制作用。本研究为黄檀属植物的资源保护和开发利用提供了科学依据。     

蔬菜育苗中低温锻炼的作用与效果研究进展

摘要：为挖掘和创制蔬菜耐低温资源,促进蔬菜产业发展,综述了低温锻炼对蔬菜形态特征、细胞超微结构、膜脂过氧化、渗透调节物质（可溶性糖和脯氨酸）、保护酶的影响的研究进展,发现可以在幼苗移栽前通过低温锻炼的方法提高植株生长势,增加可溶性糖、脯氨酸等渗透调节物质含量,增强SOD（超氧化物歧化酶）、POD（过氧化物酶）、CAT（过氧化氢酶）等保护酶活性,增强植株的耐寒能力。未来,建议加强高适宜“低温锻炼”蔬菜种质资源筛选,并深入研究蔬菜“低温锻炼”分子调控机制。