Control of Penicillium expansum by plant volatile compounds

Nine plant volatiles were tested for their activity in vitro and in vivo against Penicillium expansum , the cause of blue mould of pear. In vitro spore germination and mycelial growth assay showed a consistent fungicidal activity by trans -2-hexenal, carvacrol, trans -cinnamaldehyde and citral, while hexanal (-)- carvone, p -anisaldehyde, eugenol and 2-nonanone exhibited a progressively lower inhibition. trans -2-Hexenal was the best inhibitor of conidial germination [MIC (minimum inhibitory concentration) = 24·6  µ L L⁻¹; ED₅₀ = 10·2  µ L L⁻¹], while carvacrol was the best inhibitor of mycelial growth (MIC = 24·6  µ L L⁻¹; ED₅₀ = 9  µ L L⁻¹). The four most active compounds in in vitro studies were tested in vivo as fumigants against blue mould on pear cv. Conference. Best control was achieved by trans -2-hexenal vapour treatments (12·5  µ L L⁻¹) when applied over a 24-h period, beginning 24 h after inoculation. In contrast, carvacrol (12·5–200  µ L L⁻¹), and trans -cinnamaldehyde (50–400  µ L L⁻¹) were ineffective and citral (200  µ L L⁻¹) showed only slight effect.     

化合物的除草活性筛性

化合物的除草活性筛选是开发新除草剂的最初和最重要的阶段。为准确地评价化合物的活性和提高试验的重复性和可靠性，在进行试验时必须考虑到试材、剂量、方法、条件及环境条件等的一致性。     

固相微萃取技术的原理及应用

本文所介绍的固相微萃取技术是一项无溶剂样品制备方法，其原理是利用分析组分在样品基质提取与提取剂中的分配不同，从而达到分离目的，具有简便，经济，不使用溶剂等优点，并且能做到提取，净化浓缩和ＧＣ上进样分析同步完成，本文还对固相微萃取的装置，工作程序及应用作了介绍。     

Secretion of Natural and Synthetic Toxic Compounds from Filamentous Fungi by Membrane Transporters of the ATP-binding Cassette and Major Facilitator Superfamily

This review provides an overview of members of the ATP-binding cassette (ABC) and major facilitator superfamily (MFS) of transporters identified in filamentous fungi. The most common function of these membrane proteins is to provide protection against natural toxic compounds present in the environment of fungi, such as antibiotics produced by other microorganisms. In plant pathogenic fungi, these transporters can also be an important determinant of virulence on host plants by providing protection against plant defence compounds or mediating the secretion of host-specific toxins. Furthermore, they play a critical role in determining base-line sensitivity to fungicides and other antimycotic agents. Overexpression of some of these transporters can lead to the development of resistance to chemically-unrelated compounds, a phenomenon described as multidrug resistance (MDR). This has been observed in a variety of organisms and can impose a serious threat to the effective control of pathogenic fungi.     

地形对赤霞珠干红葡萄酒香气成分的影响

采用液液萃取法提取3种地形下赤霞珠干红葡萄酒的香气成分,用气相色谱-质谱进行分离测定,结合计算机检索技术对分离化合物进行鉴定,并应用色谱蜂面积归-法测定各成分的相对含量.结果表明:海拔较低的山地葡萄酒主要香气成分的种类和相对含量高于海拔高的山地葡萄酒,其中吲哚-3-乙醇、2-乙基己醇、己酸乙酯仅在前者中被检出;平地葡萄酒主要香气成分的种类和相对含量仅次于地势较低的山地葡萄酒,其中酯类化合物含量明显高于山地葡萄酒;苯乙醇、乙酸异戊酯等构成葡萄酒特征香气的组分在高海拔山地葡萄酒中未被检出.     

二氟甲基取代吡唑甲酰胺类化合物的合成及杀菌活性

以二氟乙酰乙酸乙酯和原甲酸三乙酯为起始原料,经亲核取代、环化、水解、氯代和酰化反应得到N-(1-甲基-2-羟乙基)-3-二氟甲基-1-甲基-1 H -吡唑-4-酰胺(4),4与取代异氰酸酯作用,合成了10个未见文献报道的二氟甲基取代吡唑甲酰胺类衍生物,其结构均经过1H NMR和MS分析确证。初步生物活性测试结果表明,在50 mg/L下,目标化合物 ZJ-3、ZJ-5、ZJ-7、ZJ-8 对瓜类炭疽病菌、瓜类灰霉病菌和水稻纹枯病菌具有一定的杀菌活性。     

The potential for using cyanobacteria (blue-green algae) and algae in the biological control of plant pathogenic bacteria and fungi

Cyanobacteria (blue-green algae) and eukaryote algae occur in freshwater, marine, and terrestrial (soil) habitats. In fact, these microorganisms comprise most of the world's biomass. Although the cyanobacteria are mostly photoautotrophic, some are facultative heterotrophs, capable of growing on certain substrates in darkness. Also, some are non-phototrophic and hence, are obligate heterotrophs. A number of cyanobacteria and eukaryote algae, particularly macroalgae, produce various, biologically active compounds. These include antibiotics which in laboratory tests inhibited bacteria and fungi that incite diseases of humans. In addition, the following fungi which are of interest to plant pathologists, were inhibitedin vitro by substances produced by various cyanobacteria: The saprophytesChaetomium globosum, Cunninghamella blakesleeana, andAspergillus oryzae and the plant pathogensRhizoctonia solani andSclerotinia sclerotiorum. Extracts from seaweeds (macroalgae) sprayed on plants have been reported to reduce the incidence ofBotrytis cinerea (gray mold) on strawberries,Erysiphe polygoni (powdery mildew) on turnips, and damping-off of tomato seedlings. Because many cyanobacteria and algae produce a large number of antibacterial and antifungal materials, are almost never a threat to the environment, and many can be grown in quantity in mass culture, they are suitable candidates for exploitation as biocontrol agents of plant pathogenic bacteria and fungi. Much additional work remains to be done however, to thoroughly evaluate cyanobacteria and algae and their products for this role.     

铵类化合物对南方根结线虫2龄幼虫存活的影响

在实验室内寄主体外测定了铵类化合物对南方根结线虫2龄幼虫（Meloidogyne incognita J2）存活的影响。结果表明：供试的8种化合物在不同浓度下对南方根结线虫J2有不同程度的致死作用,并且随着浓度的升高致死效果均显著增加。其中NH4HCO3对J2作用最为敏感,浓度为0.025 mol/L（25 ℃,pH 7.95）时校正死亡率达53.5%,浓度达到0.05 mol/L（25 ℃,pH 8.20）时校正死亡率可达100%,而其他化合物只有在高浓度时致死效果才显现出来。致死浓度由低到高的顺序为：NH4HCO3＜(NH4)2SO4＜NH4CNS＜NH4NO3 ＜NH4H2PO4＜NH4Cl＜(NH4)3PO4•3H2O＜(NH4)2HPO4。同时测定了南方根结线虫J2的酸度适应范围是pH4.1~11.0。     

农药产品中微量N-亚硝基化合物的检测研究

根据N-亚硝基化合物的性质,利用化学去亚硝基反应,制定了测定农药产品中N-亚硝基化合物的分光光度法,试验结果表明,N-二甲基亚硝胺浓度在0.02～3μg/mL范围内呈线性关系,该法用于测定农药产品分析,5次测定结果RSD为2.2%。     

取代双吡唑类化合物的合成及杀虫活性

以3-氯苯肼盐酸盐( 1 )和1,1,3,3-四甲氧基丙烷( 2 )为起始原料,经环化、Vilsmeier反应得1-(3-氯苯基)-1H-吡唑-4-甲醛( 4);(4 )与3-三氟甲基苯乙酮( 5 )经Claisen-Schmidt缩合反应得取代芳基烯酮类化合物( 6 ),再与水合肼发生环化反应得3-(3-三氟甲基苯基)-5-(3-氯苯基-1H-吡唑)-4,5-二氢吡唑( 7),其与取代异氰酸酯 作用,制得15个未见文献报道的结构新颖的取代双吡唑类化合物。利用核磁共振氢谱(1H NMR)和质谱(MS)对其结构进行了表征。初步生物活性测定结果表明,在 500 mg/L 质量浓度下,部分化合物对小菜蛾Plutella xylostella的致死率达100%,而对苜蓿蚜Aphis medicaginis、稻褐飞虱Nilaparvata lugens、朱砂叶螨Tetranychus cinnabarinus均无杀虫活性。     

新型含芳醚结构三唑类化合物的合成及植物生长调节活性

为了寻求新的、高活性的三唑类农药,将芳醚结构引入三唑类化合物中,设计合成了未见报道的4'-芳氧基-2-(1H-1,2,4-三氮唑-1-基)-苯乙酮类和1-(4'-芳氧基苯基)-2-(1H-1,2,4-三氮唑-1-基)乙醇类共8个化合物。采用核磁共振氢谱、碳谱及元素分析确认了新化合物的结构。生物活性测试结果表明,所合成的化合物对小麦和油菜的发芽及根、茎生长具有一定的调节作用。     

五种挥发性化合物对土传病原真菌及线虫的生物活性

为明确挥发性化合物反式-2-己烯醛、香茅醛、1-辛烯-3-醇、芳樟醇、1-戊烯-3-醇对土传病害及线虫病的防治潜力,采用密封盘菌丝生长速率法比较了挥发性化合物对辣椒疫霉等7种植物土传病原真菌、南方根结线虫和禾谷孢囊线虫的生物活性。反式-2-己烯醛和香茅醛的生物活性高于1-辛烯-3-醇、芳樟醇及1-戊烯-3-醇,21.0μL/L反式-2-己烯醛处理能够完全抑制供试病原真菌菌丝的生长。10.5μL/L反式-2-己烯醛或香茅醛处理对花生冠腐病菌孢子及棉花黄萎病菌色素的产生均有较强的抑制作用,且42.0μL/L处理能够完全抑制黄瓜菌核病菌菌核的萌发。2.62μL/L反式-2-己烯醛处理南方根结线虫和禾谷孢囊线虫的2龄幼虫,24h的死亡率均为100%;2.62μL/L香茅醛处理24 h的死亡率分别为95.4%和89.5%,而对照处理的死亡率分别为2.5%和3.0%。研究表明反式-2-己烯醛及香茅醛具有较好的熏蒸抑菌及杀线虫活性。     

外源褪黑素对番茄果实品质和挥发性物质的影响

为探究外源褪黑素对番茄果实品质及挥发性物质的影响,以番茄（Solanum lycopersicum）‘航粉高糖’品种为试材,以果实表面喷施蒸馏水为对照（CK）,设4个不同浓度褪黑素喷施果实处理,分别为T1（50 μmol·L^-1）、T2（100 μmol·L^-1）、T3（150 μmol·L^-1）、T4（200 μmol·L^-1）。结果表明：（1）100 μmol·L^-1外源褪黑素处理能显著增加番茄果实中果糖、葡萄糖和可溶性总糖的含量,降低有机酸含量,从而显著提高番茄果实糖酸比。（2）5个处理中共检测出86种挥发性物质,包括12种酮类、32种醛类、14种醇类、4种酯类、13种烃类、7种酚类和4种其他类物质。各处理挥发性物质总数量和总含量依次为：CK（55种,1 279.18 μg·kg^-1）、T1（69种,1 960.95 μg·kg^-1）、T2（66种,2 258.70 μg·kg^-1）、T3（62种,1 818.84 μg·kg^-1）、T4（59种,1 695.04 μg·kg^-1）,均为醛类含量最高,酚类含量最低,其中100 μmol·L^-1处理可提高番茄果实中酮类、醛类、醇类和酯类挥发性物质总含量。检测出的挥发性物质共包含10种番茄特征香气成分,100 μmol·L^-1处理的特征挥发性物质含量最高,为1 307.34 μg·kg^-1。（3）与对照相比,喷施褪黑素提高了番茄果实单果质量以及可溶性固形物、可溶性蛋白、维生素C、番茄红素含量,促进果实对N、K、Mg、Cu、Fe、Zn等矿质元素的吸收。（4）主成分分析表明,各处理的综合得分表现为T2>T1>T3>T4>CK。综上,外源喷施褪黑素可显著提高番茄果实的营养和风味品质,且100 μmol·L^-1浓度效果最佳。     

Arbuscular mycorrhizal fungal colonization of GlycyrrhJza glabra roots enhances plant biomass,phosphorus uptake and concentration of root secondary metabolites

Arbuscular mycorrhizal(AM)fungi penetrate the cortical cells of the roots of vascular plants,and are widely distributed in soil.The formation of these symbiotic bodies accelerates the absorption and utilization of mineral elements,enhances plant resistance to stress,boosts the growth of plants,and increases the survival rate of transplanted seedlings.We studied the effects of various arbuscular mycorrhizae fungi on the growth and development of licorice(Glycyrrhiza glabra).Several species of AM,such as Glomus mosseae,Glomus intraradices,and a mixture of fungi(G.mosseae,G.intraradices,G.cladoideum,G.microagregatum,G.caledonium and G.etunicatum)were used in our study.Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi,plant dry biomass,phosphorus concentration and concentration of secondary metabolites.We established two cloned strains of licorice,clone 3(C3)and clone 6(C6)to exclude the effect of genotypic variations.Our results showed that the AM fungi could in fact increase the leaf and root biomass,as well as the phosphorus concentration in each clone.Furthermore,AM fungi significantly increased the yield of certain secondary metabolites in clone 3.Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants.There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.     

Arbuscular mycorrhizal fungal colonization of Glycyrrhiza glabra roots enhances plant biomass,phosphorus uptake and concentration of root secondary metabolites

Arbuscular mycorrhizal(AM)fungi penetrate the cortical cells of the roots of vascular plants,and are widely distributed in soil.The formation of these symbiotic bodies accelerates the absorption and utilization of mineral elements,enhances plant resistance to stress,boosts the growth of plants,and increases the survival rate of transplanted seedlings.We studied the effects of various arbuscular mycorrhizae fungi on the growth and development of licorice(Glycyrrhiza glabra).Several species of AM,such as Glomus mosseae,Glomus intraradices,and a mixture of fungi(G.mosseae,G.intraradices,G.cladoideum,G.microagregatum,G.caledonium and G.etunicatum)were used in our study.Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi,plant dry biomass,phosphorus concentration and concentration of secondary metabolites.We established two cloned strains of licorice,clone 3(C3)and clone 6(C6)to exclude the effect of genotypic variations.Our results showed that the AM fungi could in fact increase the leaf and root biomass,as well as the phosphorus concentration in each clone.Furthermore,AM fungi significantly increased the yield of certain secondary metabolites in clone 3.Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants.There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.     

From synthetic control to natural products: a focus on N‐heterocycles

Natural products containing a N‐heterocycle motif are widespread in nature and medicinal plants, in particular, have proved to be a source of almost unlimited N‐derived structures with high molecular diversity. Because of their intrinsic potential for use in both biomedical and agricultural applications, there is a general need for new compounds and for the synthesis of ‘natural‐inspired’ analogues. Importantly, transition of a natural product from discovery to a ‘market lead’ is associated with an increasingly challenging demand for more of the compound, which cannot be met by isolation from natural plant sources, often due to low extraction yields and uneven availability of the plant source itself. Synthesis remains the most reliable approach to provide valuable products for the market. In this review, a comprehensive overview of our contribution to synthetic access to N‐derived natural products is given. Major strengths of the proposed methodologies are discussed critically. © 2019 Society of Chemical Industry     

Risk assessment to honey bees: a scheme developed in France for non-sprayed systemic compounds

BACKGROUND: Directive 91/414/EEC envisages that the systemic properties of active substances, if any, are taken into account in evaluating the risk posed to the environment by plant protection products. Among others, honey bees may be exposed to substances via this route, which may pose problems when substances with high toxicity are ingested through pollen or nectar. The guidance documents in support of the risk assessment to bees within the framework of Directive 91/414/EEC do not provide detailed technical guidance on how to proceed in a risk assessment for substances with systemic properties. RESULTS: A stepwise approach aiming specifically to assess the risk posed by non-sprayed systemic substances to bees is therefore proposed. This approach first identifies substances with systemic properties, which should be quantified in plant material as pollen and nectar. Exposure estimates calculated for different categories of bees (e.g. foraging bees), based on expected concentrations of the product in pollen or nectar, may be compared with several toxicity endpoints for acute or chronic effects on adults and/or larvae with a toxicity/exposure ratio, which is a measurement of potential risks. CONCLUSION: Such a ratio is proposed to be used as a trigger for any further refined assessment that would focus on the measurement of effects at the colony level.     

非嗜食植物中的昆虫产卵驱避物及其利用

产卵是植物性昆虫生命周期中的一个重要环节，它能反映昆虫与植物相互作用的某些特点以及植食性昆虫对植物利用的策略。植物中的驱避物质在调节昆虫产卵行为过程中超着十分重要的作用。大量研究结果表明：许多非嗜食植物含有对昆虫产卵有驱避作用的次生化合物。研究植物中的昆虫产卵驱避物质不仅能在理论上加深对植食性昆虫产卵机制，植食性昆虫与植物间的相互关系以及昆虫群落构建机制等的认识，同时在害虫综合治理中有广泛的应用前景。     

一种测试鳞翅目幼虫嗅觉行为的高效选择装置

昆虫的寄主定位、产卵选择、聚集、求偶等行为受到来自昆虫周围环境的挥发性气味化合物的影响和调控。研究挥发物对昆虫行为的影响作用主要采用Y形嗅觉仪等行为检测装置,而研究挥发物对鳞翅目幼虫的影响作用却缺乏专业、高效的装置。本研究设计制作了研究鳞翅目幼虫行为的高效选择装置,适用于高效筛选对鳞翅目幼虫具有引诱、驱避等作用的挥发物。小菜蛾3龄幼虫的行为选择测试结果表明,对小菜蛾幼虫引诱最强的植物为大白菜,其次是油菜和甘蓝;花生叶片对小菜蛾幼虫没有作用;而番茄叶片对小菜蛾幼虫则具有驱避作用。由此说明该装置可以有效测定小菜蛾幼虫对不同挥发物的反应,将为挥发物对昆虫行为的影响研究、进而筛选新的化合物来控制虫害提供新的技术支持。     

Antimicrobials in Phytophthora isolation media and the growth of Phytophthora species

Many recently described Phytophthora species detected using high-throughput sequencing have never been isolated into culture. NARH is a commonly used isolation medium containing cornmeal agar with n ystatin 22.72 ppm, a mpicillin 100 ppm, r ifampicin 10 ppm, and h ymexazol 50 ppm. We investigated whether the antimicrobial compounds in this medium selectively inhibit growth of some Phytophthora species. Growth of 10 Phytophthora species from 10 Phytophthora clades was tested in NARH medium with antimicrobials in a range of concentrations, singly and in combination: nystatin 12.5–100 ppm, ampicillin 62.5–500 ppm, rifampicin 5–40 ppm, hymexazol 12.5–100 ppm and in addition, chloramphenicol 5–40 ppm. Two combinations of antimicrobials that supported good growth of the greatest number of species were selected: (a) nystatin 12.5 ppm, ampicillin 250 ppm, rifampicin 10 ppm, and hymexazol 12.5 ppm, and (b) these compounds with the addition of chloramphenicol 5 ppm. Subsequently the growth of 47 Phytophthora species from all clades was tested in media with these two combinations and standard NARH, both in aseptic culture and in plates with leaf baits infected from soils known to be infested with Phytophthora. Although growth of some Phytophthora species was better with the new combinations of antimicrobials in aseptic culture, suppression of competing microorganisms was best in standard NARH. Sensitivity to the NARH antimicrobials is not the reason for the difficulty or failure of isolating many species detected using high-throughput sequencing. NARH is a robust and appropriate medium for isolation of Phytophthora species from all clades.