有机重金属复合污染对香樟吸收营养离子的影响

采用土培试验研究了聚已戊二酯重金属复合污染处理对香樟吸收营养元素的影响。研究结果表明:高浓度重金属可以增加根部对Ca2+、Fe2+吸收,增加叶片对Ca2+、Mg2+的吸收,但降低了香樟根部对Mg2+及叶片对Fe2+的吸收。与有机浓度100mg/kg处理相比,根和叶在有机浓度为50mg/kg对Ca2+、Mg2+的吸收能力有所增强,但对Fe2+的吸收能力有所减弱。根部吸收重金属离子与吸收营养元素离子间呈现显著的相关性,但叶中重金属吸收和营养元素吸收之间没有明显的相关关系。     

香豆素分子印迹复合膜的制备与性能研究

在优化了载体膜种类、引发剂与交联剂用量以及载体膜在预聚合溶液中的浸泡时间基础上,以聚偏氟乙烯(PDVF)为载体膜,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,固定模板、单体及交联剂的加入量比为1:4:8,在乙腈中用AIBN引发聚合反应,制备了一种对香豆素具有较高吸附容量(0.151 8 mmol/g)和理想印迹因子(2.09)的香豆素分子印迹复合膜.用红外光谱和扫描电镜表征了膜的结构与形貌,探讨了膜的传质机制及其渗透选择性.结果表明,在浓度差驱动下,该膜通过溶解-扩散机理进行传质,并在有干扰物存在时,对香豆素具有良好的分离选择性,从桂枝甲醇粗提液中提取分离香豆素的回收率达到了89.6%.     

香樟受酸胁迫影响的高光谱诊断模型

高光谱作为快速、无损诊断技术,在植物胁迫监测中发挥了重要作用。但是因为硫和氮的施肥作用,植物对酸雨的响应表现出比其他胁迫更加复杂的模式。基于高光谱技术对香樟受四个酸雨梯度(pH 5.6,pH 4.5,pH 3.0,pH 2.0)影响的叶片光谱进行了419天的监测,以探讨不同酸雨梯度对香樟影响的时间拐点。首先对16期原始光谱数据进行预处理,剔除异常值;然后基于光谱差值(对照组pH 5.6与其他酸雨梯度处理下的叶片光谱差)随着喷酸时间的变化,寻找典型波段;在此基础上构建了香樟在酸雨处理下的光谱响应模型。主要结论如下：反映香樟受酸雨影响的典型波段主要集中在470~520和565~700 nm,在此基础上构建了蓝边差值指数和黄边差值指数。低(pH 4.5)、中(pH 3.0)浓度的酸雨对香樟生长均呈现出先促进后抑制的作用,时间拐点分别发生在喷酸的第100天和50天左右;高浓度酸雨(pH 2.0)从喷酸初期就表现出抑制香樟生长,且随着喷酸时间的增加抑制作用增强。研究表明,长时间序列的高光谱信息可以指示不同强度的酸雨对植物的促进和胁迫作用,以及由促进到胁迫的时间拐点;该研究也为基于卫星遥感监测区域尺度植物受酸胁迫提供了借鉴,同时为相关部门制定酸雨政策提供了科学依据。     

植被叶片光谱特征对烟煤病胁迫程度的响应模型研究

烟煤病是我国南方热带、亚热带地区一种非常普遍的植物病害,对我国农业生产造成巨大危害,对其监测预报是实施有效治理措施的重要基础和依据。为建立以高光谱数据为基础的烟煤病严重程度反演模型,在重庆北碚城区采集50个银木叶片样本,利用ASD FieldSpec HandHeld光谱仪获取高光谱数据,通过数码相机和ENVI软件获取叶面积数据,将银木叶片烟煤病面积与整个叶片面积的比例作为烟煤病的严重程度,建立相关性最大波段的烟煤病反演模型,探究烟煤病严重程度与光谱曲线之间可能存在的关系。结果表明： 单叶尺度下,健康叶片在560 nm波段附近有明显的反射峰,随着烟煤病严重程度增大,反射峰逐渐消失, 在可见光与近红外波段,总体上光谱反射率与烟煤病病情严重程度呈负相关性。500～650和720～850 nm为烟煤病的光谱敏感波段,其中相关度最大值点为550 nm波段,相关系数达到-0.72。在烟煤病严重程度与叶片波段原始光谱信息及多波段组合关系研究中,单叶尺度下785 nm波段高光谱参数与烟煤病严重程度建立的回归模型的决定系数(R2)最大,为0.875。通过模型的显著性检验和预测精度检验, 785nm 处的光谱反射率建立的二次曲线模型为最优。证明在单叶尺度下,基于785 nm波段的二次曲线模型反演烟煤病的效果较为理想。     

Analysis of the Volatile Components in the Leaves of Cinna-momum camphora by Static Headspace Gas Chromatography Mass Spectrometry Combined with Accurate Weight Measurement

The volatile components in the leaves of C. camphora were analyzed by static headspace‐gas chromatography/mass spectrometry (HS‐GC‐MS) combined with accurate weight measurement. Accurate weight measurement obtained by Time‐of‐Flight mass spectrometry (TOF‐MS) helped to confirm the identification of volatiles in the analysis. 59 volatile components in the leaves of C. camphora were identified, which mainly included cis‐3‐hexen‐1‐ol (5.6%), 3‐hexen‐1‐ol, acetate (Z) (11.1%), β‐caryophyllene (15.4%), bicyclogermarene (8.4%), trans‐nerolidol (19.5%) and 9‐oxofarnesol (7.7%). The results show that method using HS‐GC‐MS combined with accurate weight measurement achieves reliable identification and has extensive application in the analysis of volatile components present in complex samples.     

碳源对不同产地香樟体细胞胚胎发生及植株再生的影响

【目的】 探究渗透调节物质种类及其不同浓度对香樟体细胞胚胎发生及植株再生的影响,为提高香樟体胚诱导率、优化体细胞胚胎发生体系奠定理论基础。【方法】 以7月初在湖南省郴州、长沙、娄底及怀化市采集的香樟(Cinnamomum camphora L.)的未成熟合子胚为试验材料,分析不同碳源种类、浓度及组合方式对香樟体胚诱导、芽萌发、生根等方面的影响。【结果】 适合香樟的体胚诱导培养基为MS+1.0 mg/L的6-苄氨基腺嘌呤(6-BA)+0.3 mg/L的2,4-二氯苯氧乙酸(2,4-D)+1.0 mg/L 链霉素+15 g/L 蔗糖+30 g/L 山梨醇+6.5 g/L 琼脂+700 mg/L水解酪蛋白;增殖培养基为MS+15 g/L 蔗糖+30 g/L 山梨醇+6.5 g/L 琼脂+700 mg/L 水解酪蛋白;芽萌发培养基为MS+0.1 mg/L 苯基噻二唑基脲(TDZ)+0.5 mg/L 萘乙酸(NAA)+0.1 mg/L 吲哚丁酸(IBA)+15 g/L 蔗糖+15 g/L 山梨醇+6.5 g/L 琼脂;生根培养基为MS+1.0 mg/L IBA+15 g/L 蔗糖+15 g/L 山梨醇+6.5 g/L 琼脂。【结论】 经过改良,添加15 g/L蔗糖和30 g/L山梨醇的组合碳源,香樟体胚的诱导率明显提高;添加15 g/L蔗糖和15 g/L山梨醇的组合碳源处理的新植株生根条数多、主根明显,生长状况更优。     

黄连配伍肉桂前后微量元素的成分分析

考察黄连配伍肉桂前后微量元素的含量；定量测定黄连配伍肉桂前后微量元素含量的变化．用日立835微量元素分析仪．共测定了12种微量元素的含量．结果表明，黄连与肉桂配伍后某些微量元素含量会下降，且下降程度与肉桂的比例有关．     

米槁采种容器育苗脱脂技术研究

本文以草木灰、稀硫酸、稀盐酸、石灰水、洗衣粉等试剂分别对米槁鲜种进行6h、12h、18h和24h的拌种和浸种处理容器育苗，结果表明，采用草木灰拌种24h和采用洗衣粉水溶液浸种24h时，均能显著缩短米槁种子的始苗期、全苗期，以及显著提高米槁种子的发芽率和增加米槁幼苗的高、径生长量。     

Efficient approach for the extraction of proanthocyanidins from Cinnamomum longepaniculatum leaves using ultrasonic irradiation and an evaluation of their inhibition activity on digestive enzymes and antioxidant activity in vitro

Proanthocyanidins were separated for the first time from Cinnamomum longepaniculatum leaves. An experiment‐based extraction strategy was used to research the efficiency of an ultrasound‐assisted method for proanthocyanidins extraction. The Plackett–Burman design results revealed that the ultrasonication time, ultrasonic power and liquid/solid ratio were the most significant parameters among the six variables in the extraction process. Upon further optimization of the Box–Behnken design, the optimal conditions were obtained as follows: extraction temperature, 100°C; ethanol concentration, 70%; pH 5; ultrasonication power, 660 W; ultrasonication time, 44 min; liquid/solid ratio, 20 mL/g. Under the obtained conditions, the extraction yield of the proanthocyanidins using the ultrasonic‐assisted method was 7.88 ± 0.21 mg/g, which is higher than that obtained using traditional methods. The phloroglucinolysis products of the proanthocyanidins, including the terminal units and derivatives from the extension units, were tentatively identified using a liquid chromatography with tandem mass spectrometry analysis. Cinnamomum longepaniculatum proanthocyanidins have promising antioxidant and anti‐nutritional properties. In summary, an ultrasound‐assisted method in combination with a response surface experimental design is an efficient methodology for the sufficient isolation of proanthocyanidins from Cinnamomum longepaniculatum leaves, and this method could be used for the separation of other bioactive compounds.     

Thermal Degradation of Linalool-Chemotype Cinnamomum osmophloeum Leaf Essential Oil and Its Stabilization by Microencapsulation with β-Cyclodextrin

The thermal degradation of linalool-chemotype Cinnamomum osmophloeum leaf essential oil and the stability effect of microencapsulation of leaf essential oil with β-cyclodextrin were studied. After thermal degradation of linalool-chemotype leaf essential oil, degraded compounds including β-myrcene, cis-ocimene and trans-ocimene, were formed through the dehydroxylation of linalool; and ene cyclization also occurs to linalool and its dehydroxylated products to form the compounds such as limonene, terpinolene and α-terpinene. The optimal microencapsulation conditions of leaf essential oil microcapsules were at a leaf essential oil to the β-cyclodextrin ratio of 15:85 and with a solvent ratio (ethanol to water) of 1:5. The maximum yield of leaf essential oil microencapsulated with β-cyclodextrin was 96.5%. According to results from the accelerated dry-heat aging test, β-cyclodextrin was fairly stable at 105 °C, and microencapsulation with β-cyclodextrin can efficiently slow down the emission of linalool-chemotype C. osmophloeum leaf essential oil.