A Novel Catechol Oxidase Enzyme Electrode for the Specific Determination of Catechol

An enzyme electrode for the specific determination of catechol was developed by using catechol oxidase (EC 1.10.3.1) from eggplant (Solanum melangena L.) in combination with a dissolved oxygen probe. Optimization studies of the prepared catechol oxidase enzyme electrode established a phosphate buffer 50 mM at pH 7.0 and 35°C to provide the optimum conditions for affirmative electrode response. The enzyme electrode response depended linearly on a catechol concentration range of 5?10^-7-30?10^-5 M with a response time of 25 sec and substrate specificity of the catechol oxidase electrode of 100%. The biosensor retained its enzyme activity for at least 70 days.     

茄子幼苗耐低温性生理机制研究

选择耐低温性不同的6份茄子高代自交系幼苗为材料,进行白天10℃/夜间7℃低温处理10d,调查其耐低温性、生长指标(株高、茎粗、鲜重、干重)、生理指标(POD、SOD、APX活性及脯氨酸含量),以探讨低温对茄子幼苗生长过程中的生长和生理指标的影响.结果显示:(1)各材料的上述性状在常温下均差异不显著,而在低温处理下差异极显著;与对照相比较,幼苗株高、茎粗、鲜重和干重下降,而POD、SOD、APX活性及脯氨酸含量上升.(2)各材料指标的升降幅度与其低温耐受性密切相关,耐低温性强的材料生长指标下降幅度较小,而生理指标提高幅度较大,耐低温性弱的材料则表现相反.(3)各指标间相比较,茄子耐低温性与株高、茎粗、干重、POD活性、SOD活性呈显著正相关,与其余性状的相关未达显著水平.研究表明,低温使茄子幼苗的生长受到一定程度的抑制,但耐低温材料能够通过调节自身的保护酶系统活性来减轻低温的伤害,维持植物体的正常生长及生理代谢功能.     

不同连作年限土壤对茄子土壤生物学活性的影响及其嫁接调节

探讨了不同连作年限土壤对茄子根际土壤微生物数量、土壤酶活性的影响及其相关性和嫁接对重要相关因子的调节作用。结果表明:随着连作年限的增加,茄子根际土壤细菌数量和放线菌数量呈下降趋势,真菌数量呈增加趋势;根际土壤中的过氧化氢酶、过氧化物酶、多酚氧化酶、蛋白酶的活性呈降低趋势;土壤微生物数量和土壤酶活性之间有显著的相关性。其中过氧化氢酶、过氧化物酶、多酚氧化酶、蛋白酶是影响根际土壤中细菌和放线菌数量的主要因子,蛋白酶是影响根际土壤中真菌数量的主要因子。嫁接能提高土壤酶活性,缓解连作土壤带来的胁迫。     

Identity and genetic structure of eggplant fruit and shoot borer,Leucinodes orbonalis Guenée (Lepidoptera:Crambidae) populations in the Philippines inferred from morphological traits and COI sequence data

Morphological and molecular analysis of 15 Philippine populations of eggplant fruit and shoot borer (EFSB), Leucinodes orbonalis Guenée were conducted to determine if these populations are constituted singly by L. orbonalis or by different species and to assess the level of variability among them. Morphometric analysis of five genital traits of 850 male adult EFSB from field populations and analysis of the COI gene sequence of 879 F₁ EFSB larvae from 15 main eggplant-producing provinces identified all individuals as belonging to L. orbonalis. Principal Component Analysis of five morphometric genital characters revealed high similarity among the EFSB populations regardless of geographic location. Thirteen (13) sequence variants (haplotypes) were identified, with one haplotype predominant and widespread throughout the country. The remaining haplotypes occurred rarely and differed from the widespread haplotype by one mutation. Overall, the EFSB populations from Philippines exhibited low nucleotide and haplotype diversity, indicating low genetic diversity. Topologies from a maximum likelihood tree indicate all thirteen haplotypes cluster in a single clade with EFSB populations from India and other South-East Asian countries. Further analysis with the Generalized Mixed Yule Coalescent (GMYC) method classified the different haplotypes into a single GMYC entity. Combined with morphometric analysis, differences between haplotypes are not suggestive of any subspecies. Negative values of Tajima's D and Fu's F_s tests combined with the phylogenetic analysis and overall low genetic diversity of Philippine populations support the hypothesis that EFSB is not endemic but introduced to the Philippines.     

紫外线阻断膜防控茄子害虫效果及对植株生长和果实品质的影响

【目的】紫外线阻断膜可以吸收光线中波长在380 nm以下的紫外光,从而影响昆虫的视觉反应,因此有望用于害虫防控。本研究旨在明确该项措施的可行性。【方法】以日光温室茄子Solanum melongena为作物对象,对紫外线阻断棚和使用普通棚膜的对照棚中3种主要害虫(西花蓟马Frankliniella occidentalis、烟粉虱Bemisia tabaci和桃蚜Myzus persicae)的发生情况进行了比较,分析了紫外线缺失对茄子植株生长和果实品质的影响。【结果】紫外线阻断棚中西花蓟马、烟粉虱和桃蚜的最大发生量均显著低于对照棚(P0.05),分别是对照棚中的44.3%,50.4%和37.5%;与对照棚相比,紫外线阻断棚中茄子株高偏高,但二者差异不显著(P0.05);紫外线阻断棚中茄子产量、果实重量和周长均降低,茄子果实颜色偏浅,果实中维生素C、可溶性糖、可滴定酸、粗脂肪和花青素含量下降(P0.05),Ca,K,Cu和Zn等矿物离子含量上升(P0.05)。【结论】本研究表明紫外线阻断技术可以显著抑制温室茄子上3种主要害虫的种群增长,但对茄子的生长和果实品质有一定影响。今后需要进一步研究该项技术在茄子品种和其他作物中的应用方式。     

Potential of Tissue Culture for Breeding Root-Knot Nematode Resistance into Vegetables

Plant protoplast technology is being investigated as a means of transferring root-knot nematode resistance factors from Solanum sisymbriifolium into the susceptible S. melongena. Solanum sisymbriifolium plants regenerated from callus lost resistance to Meloidogyne javanica but retained resistance to M. incognita. Tomato plants cloned from leaf discs of the root-knot nematode resistant ''Patriot'' were completely susceptible to M. incognita, while sections of stems and leaves rooted in sand in the absence of growth hormones retained resistance. Changes in resistance persisted for three generations. It is postulated that the exogenous hormonal constituents of the culture medium are modifying the expression of genetic resistance.     

Hydroperoxide isomers and ketohydroxy product from oxidation of linoleic acid by eggplant lipoxygenase

Hydroperoxides produced by oxidation of linoleic acid with purified eggplant lipoxygenase were separated by TLC and analysed by IR spectroscopy. The methyl hydroxystearates from the enzymatically produced hydroperoxides were analysed by MS and GLC. Both analyses indicated that the eggplant enzyme converted linoleic acid almost exclusively (96%) into the 13-hydroperoxy isomer whereas the 9-hydroperoxy isomer was only a minor product (4%). HPLC of the methyl ester of the isolated hydroperoxides showed three components. Each component was collected, reduced to methyl hydroxystearate and characterized by GLC, MS and IR analysis. The components were identified as 13-hydroperoxy cis-trans isomer (92.8%), 13-hydroperoxy trans-trans isomer (2.6%) and 9-hydroperoxy cis-trans isomer (4.6%). A polar by-product present in the reaction mixture was identified by IR, ¹H NMR, and MS (of the toluene-p-sulphonyl derivative) as 13-hydroxy-12-oxo-octadec-cis-9-enoic acid.     

茄子体内α-茄碱的含量检测及分布特点

以不同品种的茄子（Solanum melomgena L.）为试材,采用超声波提取技术和高效液相色谱法对茄子不同器官、不同颜色、不同采收时期和不同成熟度的果实及果实不同部位中α-茄碱进行提取和测定,旨在明确茄子体内α-茄碱的含量及分布特点。结果表明,茄子不同器官中,果实中α-茄碱含量最高;紫茄品种α-茄碱含量显著高于绿茄;不同时期采收的果实中以门茄中α-茄碱含量最高;未成熟茄子果实中α-茄碱含量显著高于成熟的茄子果实;各茄子品种果肉中α-茄碱含量显著高于果皮和果蒂。