蓝莓采后果实致腐菌的分离鉴定及植物精油对其抑制作用的研究

为明确山东泰安本地蓝莓采后果实致腐菌及植物精油的抑菌效果,本研究从自然发病的蓝莓果实上分离致腐菌株,采用传统真菌形态学、rDNA-ITS序列分析,结合构建系统进化发育树进行鉴定,并通过体外熏蒸抑菌试验研究植物精油的抑菌效果。结果表明:经鉴定该病原菌为尖孢镰刀菌(Fusarium oxysporum);6种植物精油对尖孢镰刀菌均有不同程度的抑菌活性,其中肉桂皮精油抑菌活性最强,对尖孢镰刀菌的抑制中浓度(EC_(50))和最小抑制浓度(MIC)分别为0.025 7μL/mL和0.060μL/mL。研究结果可为山东地区蓝莓货架期真菌病害的预测和防控提供一定的理论依据。     

5种植物精油抗菌性能研究及特征成分分析

精油富含多种抗菌成分,在天然抗菌剂的开发方面具有较好潜力。采用二倍稀释法研究丁香、薰衣草、桉叶、香茅、肉豆蔻5种精油的体外抑菌活性,通过悬浮培养定量测定各精油对革兰氏阴性菌、革兰氏阳性菌的最小抑菌浓度（MIC）,并应用气相色谱-质谱联用仪（GC-MS）分析了5种植物精油的组成成分及相对含量。结果显示：丁香精油、薰衣草精油、桉叶精油、香茅精油、肉豆蔻精油对大肠杆菌的MIC分别为1.25、5.00、10.00、10.00、5.00 ?滋g/mL,对枯草芽孢杆菌的MIC分别为0.63、1.25、2.50、1.25、0.31 ?滋g/mL。GC-MS结果显示：丁香精油主要组分为丁香酚（84.90%）和石竹烯（13.27%）;薰衣草精油主要组分为乙酸芳樟酯（34.05%）和芳樟醇（28.40%）;桉叶精油主要组分为桉树醇（34.29%）和柠檬烯（18.29%）;香茅精油主要为香茅醛（16.22%）和花侧柏烯（16.04%）;肉豆蔻精油主要为柠檬烯（32.68%）和蒎烯（23.96%）。5种精油具有良好的抑菌活性,可为更好地开发抗生素替代品提供理论依据。     

植物提取物及杀菌剂对水稻白叶枯病菌的抑菌活性

采用带药平板涂布法测定了24种植物甲醇提取物、3种植物化合物、1种植物精油和13种杀菌剂对水稻白叶枯病菌的抑菌活性。结果表明,在植物提取物中,广西地不容块根、黔桂千金藤块根、石菖蒲根茎和木防己块根对水稻白叶枯病菌有抑菌活性,最低抑制浓度(MIC)分别为2g/L、6g/L、2g/L和6g/L;3种植物化合物中,罗默碱对水稻白叶枯病菌有很好的抑制活性,最低抑制浓度为0.025g/L,千金藤碱和克斑宁在浓度为2g/L时无抑菌活性;石菖蒲精油对水稻白叶枯病菌的最低抑制浓度为1g/L。在13种杀菌剂中,75%百菌清WP、80%代森锰锌WP、60%甲硫.异菌脲WP、53.8%可杀得WG、20%叶枯唑WP、58%甲霜.锰锌WP、64%杀毒矾WP和3%中生菌素WP对水稻白叶枯病菌的最低抑制浓度分别为7.5g/L、1.067g/L、0.75g/L、0.269g/L、0.2g/L、0.048g/L、0.032g/L和0.03g/L;72%农用链霉素SP、50%敌克松WP、15%三唑酮WP、20%噻唑锌SC和2%加收米SL5种药剂在稀释100倍时对水稻白叶枯病菌无抑制活性。     

番石榴叶精油的提取、成分鉴定及对红火蚁的生物活性分析

为评价番石榴叶精油(EO)对红火蚁的熏蒸活性，采用熏蒸法和气相色谱-质谱联用(GC-MS)等技术测定精油对红火蚁的生物活性。EO含有31种化合物，caryophyllene(37.86%)为主要化合物。生测结果表明，20 µL/管的EO熏蒸红火蚁48 h，死亡率达90%以上；熏蒸红火蚁9 h，聚集率下降了78%，攀爬率下降了45%，抓附率下降了34%，行走率下降了30%。10 µL/管的EO熏蒸红火蚁48 h，体内过氧化氢酶(CAT)和羧酸酯酶(CarE)酶活力分别降低了56.62%和58.57%，红火蚁毒腺分泌哌啶化合物的组分降低了50%。番石榴叶精油对红火蚁具备良好的熏蒸活性，并抑制其行为能力、体内酶活力及生物碱的分泌。本研究可为番石榴的深度开发及红火蚁的生物防控提供理论依据。     

4种柚子皮精油成分及其抑菌活性的研究

通过水蒸气蒸馏方法提取4种柚皮精油并比较精油得率,采用气相色谱与质谱联用(GC-MS)的方法分析了4种柚皮精油的主要成分d-柠檬烯,通过抑菌试验,探究这4种柚皮精油对于枯草芽孢杆菌、大肠杆菌、霉菌、酵母菌的抑菌效果。结果表明,4种柚皮精油得率为文旦柚梁平柚香柚沙田柚,其中文旦柚得率为1.97%,沙田柚得率为1.56%;4种柚皮精油中主要成分d-柠檬烯含量为香柚沙田柚梁平柚文旦柚,其中香柚和沙田柚的d-柠檬烯含量超过90%,梁平柚和文旦柚精油的含量为50%～60%;4种柚皮精油对4种受试菌均表现出不同的抑菌活性,d-柠檬烯含量高的香柚、沙田柚柚皮精油的抑菌活性高于d-柠檬烯含量较低的文旦柚、梁平柚,除枯草芽孢杆菌外,d-柠檬烯含量与其余3种细菌的抑菌活性之间呈正相关关系。     

含氟低聚壳聚糖衍生物抑菌作用研究

采用滤纸片法研究了6种不同结构含氟低聚壳聚糖衍生物对大肠杆菌、金黄色葡萄球菌、核盘菌、水稻纹枯病原菌、黄花枯萎病原菌、黑曲霉、青霉等7种菌的抑制作用。结果表明,不同含氟低聚壳聚糖衍生物对不同微生物的抑菌活性表现出不同程度的抑菌性。6种含氟低聚壳聚糖衍生物中,除了化合物5对黑曲霉没有抑菌性,其他几种化合物对7种受试菌株都有不同程度的抑菌性;化合物1对大肠杆菌抑制效果较好;化合物2和化合物3对7种微生物均有抑菌性,但抑菌效果较差;化合物4对大肠杆菌、金黄色葡萄球菌、黄花枯萎病原菌抑制效果较好;化合物5对大肠杆菌抑制效果较好;化合物6对金黄色葡萄球菌、水稻纹枯病原菌、黄花枯萎病原菌抑制效果较好。     

花椒精油的提取、抗菌活性研究及GC-MS分析

中国是花椒主产地。花椒的品种、生长环境以及提取方法的不同都会导致花椒精油化学组成与含量的差异。对产自山东德州的花椒采用索氏提取法提取花椒精油,分析精油抗菌活性,采用气相-质谱联用仪(GC-MS)分析精油化学成分。结果表明,不同溶剂提取所得精油在颜色、气味、状态等方面差别明显,对微生物抑制程度也不同,其中,乙醚提取的精油抗菌活性最强,对7种受试菌均有明显抑制作用。GC-MS显示在匹配度大于80%时,乙醚和石油醚提取的精油分别鉴定出45和63种物质,酮类为主要组分,2种精油中都含有大量的未被报道过的1（- 2-羟基-4,6-甲氧基苯基）乙酮。花椒精油作为花椒的重要功能成分,将会在食品呈香及抑菌防腐方面发挥重要的作用。     

精油制剂中油水混溶剂对精油抑菌效果的影响

为探讨基于油水混溶剂的复方精油对空气中沉降菌的抑制作用,本研究测定了复方精油A的抑菌效果、精油型抑菌制剂的抑菌效果和油水混溶剂对精油抑菌效果的影响。通过平板沉降法测定复方精油A的抑菌效果,并选取PEG-40氢化蓖麻油(PEG-40)、吐温80、二甲基亚砜(DMSO)、司盘85、双脱乙醇5种油水混溶剂,在复方精油A和油水混溶剂比例分别介于1:1~1:6时配制精油抑菌制剂,并验证该均匀水溶液的抑菌效果,同时采用棋盘稀释法测定油水混溶剂对复方精油A抑菌效果的影响。结果表明,复方精油A的抑菌率达到80%以上,精油抑菌制剂在平板暴露6 h的抑菌率最佳,为48.92%。油水混溶剂中PEG-40的增溶效果最佳,复方精油浓度为1%时,精油、PEG-40、双脱乙醇的最佳比例为1:2:2;浓度为3%时,精油、PEG-40、双脱乙醇的最佳比例为1:3:3。PEG-40对空气中沉降菌无抑制效果,双脱乙醇和复方精油对空气中沉降菌的抑菌效果表现为相加作用。研究对植物精油应用于产业化生产时,油水混溶剂的种类和比例对精油类产品实际效果的影响有一定的参考价值。     

香茅精油不同接触方式对体外白假丝酵母菌抑制效果的研究

采用漳州地区种植的柠檬香茅草,提取其精油分别用不同物态定量抑制白假丝酵母菌,以此筛选出该精油抑制该菌种的最佳物态及最低浓度;采用固态直接接触法、气态熏蒸法和液态混合药剂法筛选出柠檬香茅精油对供试菌种的最佳抑制物态,并在此基础上筛选出该精油抑制供试菌种的最低浓度。结果表明用固态直接接触法的抑菌效果最佳,气态熏蒸法次之,液态混合药剂法的抑菌效果最差,但仍显著优于5%氟康唑阳性对照(P0.01),柠檬香茅精油固态直接接触法抑制白假丝酵母菌的最低浓度为0.15μL/m L。实验结果可证明柠檬香茅精油在3种物态下都有良好的抑菌效果。     

5种精油的化学成分及对番茄早疫病的抑菌活性研究

为研究植物精油开发生物农药的潜力,采用水蒸气蒸馏法提取肉桂、迷迭香、薰衣草、肉豆蔻、柠檬天竺葵等5种不同植物的精油,并用气相色谱—质谱联用的方法分析精油组分。以番茄早疫病菌为供试菌种,研究不同植物精油对其抑制作用。通过分析得到肉桂精油主要成分为反式肉桂醛(52.50%),迷迭香精油中1,8-桉叶素(20.69%)含量较多,薰衣草花精油主成分为丁酸沉香酯(33.92%)和芳樟醇(29.29%);肉豆蔻精油主成分为GAMMA-萜品烯(13.00%)、(-)-4-萜品醇(12.84%)、2-蒈烯(10.37%);柠檬天竺葵精油主成分皆为β-香茅醇(32.21%)。肉桂精油对于番茄早疫病菌丝生长的抑制作用最佳,其EC50为286.62 mg/L,肉豆蔻精油的抑制效果最弱。该研究为筛选抑菌的植物精油及开发肉桂精油在生物农药的应用提供了科学的依据。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.