香草兰生防细菌的筛选、分子鉴定及其抑菌机制的初步研究

通过平板对峙法从香草兰根际微生物中筛选出对香草兰根(茎)腐病菌(Fusarium oxysporum)、香草兰疫病菌(Phytophthora nicotianae)和香草兰细菌性软腐病菌(Erwinia carotovora)均有良好抑制效果的生防菌10株。通过16S rDNA序列比对及系统发育树分析,其中7株为解淀粉芽孢杆菌(Bacillus. amyloliquefaciens),2株为枯草芽孢杆菌(B. subtils),1株为甲基营养型芽孢杆菌(B. methylotrophicus)。提取脂肽类化合物进行抑菌分析,发现10株生防菌脂肽类提取物对香草兰根(茎)腐病菌和香草兰疫病菌均有良好的抑制效果,有4株的脂肽类粗提物对香草兰细菌性软腐病菌有强烈的抑制活性。对其中2个菌株脂肽类粗提物进行MALDI-TOF/TOF-MS检测,发现菌株 VX2R11 产生表面活性素(Surfactin)和伊枯草素A(IturinA)2种脂肽类化合物,菌株 VX2S02 仅产生伊枯草素A,推测产生伊枯草素A是菌株VX2R11和VX2S02拮抗香草兰根(茎)腐病菌和疫病菌重要机制;产生表面活性素是菌株VX2R11拮抗香草兰细菌性软腐病菌的重要机制。     

香草兰根(茎)腐病病原菌鉴定及其致病性测定

香草兰根(茎)腐病是香草兰上重要病害之一,目前国内外尚未有基于rDNA-ITS序列的分子鉴定和系统发育树分析的报道。本研究从海南省万宁市的兴隆、长丰和南林等地的病样中分离获得了9个菌株,经过柯赫氏法则验证、形态学鉴定和分子鉴定,病原菌被鉴定为尖孢镰刀菌,表明海南省万宁市地区的香草兰根(茎)腐病病原菌是尖孢镰刀菌(Fusarium. oxysporum)。然后,基于rDNA-ITS序列构建了系统发育树并对菌株的致病性进行了测定,结果发现9个菌株在系统发育树中被聚类为遗传距离明显的2个分枝,而且分枝Ⅱ的致病性要高于分枝Ⅰ。本研究为香草兰根(茎)腐病病原物快速鉴定提供依据,对香草兰根(茎)腐病防治决策有一定的参考意义。     

海南省热带牧草病害调查及病原菌初步鉴定

通过对海南省14种热带牧草病害的田间调查,结果显示,常发生的病害有叶斑病、花/果/茎腐病、枝枯病等,病害类型有39种。分离鉴定的结果表明,真菌性病害32种,细菌性病害1种,根结线虫引起的病害1种,病毒类病害3种,植原体病害1种,寄生性藻类病害1种。初步查明海南省主要热带牧草病害的种类和为害状况,其中柱花草为害最为严重的病害为炭疽病(Colletotrichum gloeosporioides PenZ.),王草则以瘟病[Pyricularia grisea(Cke.)Sacc]发生最为严重,其他牧草以叶斑病为害居多,为害水平中等至轻微。     

海南省菠萝蜜主要病虫害识别与防治

分别介绍了目前在海南省菠萝蜜上发生的6种主要病虫害,炭疽病、花果软腐病、蒂腐病和榕八星天牛、桑粒肩天牛及黄翅绢野螟,以及6种病虫害的症状、病原或害虫、发生规律及防治措施,为促进菠萝蜜产业健康可持续发展提供技术参考。     

香草兰细菌性软腐病病原菌鉴定

1988年,在海南岛兴隆地区首次发现香草兰细菌性软腐病。发病叶片呈水渍状软腐,腐烂病痕的边缘有褐色线纹。在潮湿情况下病痕扩展迅速,以致全叶软腐塌萎。根据对病原菌的细菌学性状、致病性和血清学反应的测定,确认本病的病原菌属于胡萝卜欧氏软腐菌胡萝卜病原型[Erwina carotovora pv.carotovora(Jones)Bergey]。     

海南香草兰疫病发生情况调查及疫霉菌种类鉴定

通过对海南各香草兰种植园进行普查,明确了香草兰疫病目前在海南省万宁、琼海、屯昌、定安等地香草兰种植园均有发生,该病一年有两个发病高峰期,4月下旬至6月上旬和9月中旬至11月上旬;对香草兰疫病病原进行分离、形态特征鉴定和rDNA ITS序列测序分析,明确了其疫霉菌种类为烟草疫霉（寄生疫霉）Phytophthora nicotianae（P.parasitica）,交配型为A2交配型。     

棉花苗期害诊断及期综合防治

棉花苗期发生的病害约有十余种,大致可分为两类.其中重要的一类是引起烂种、烂芽、茎基腐和根腐.常见的有立枯病、炭疽病、红腐病,其次为猝倒病、枯腐病等.主要发生在子叶期至二叶真叶期.由于根茎过于幼嫩,抗病能力弱,易遭受病菌侵染而腐烂;另一类以为害子叶、真叶及茎部为主的茎枯病、疫病、黑斑病、轮纹病及苗期枯萎病等.对生产上影响较大的主要是前一类.     

人参、西洋参病害综合防治技术

人参、西洋参的病害共有30余种,从发病部位可分为地上部病害、表土中病害和地下部病害。地上部病害主要有黑斑病(斑点病、褐斑病、茎斑病)、疫病、灰霉病、炭疽病、白粉病等;表土中病害主要有立枯病、猝倒病、茎腐病等;地下部病害主要有锈腐病、根腐病(细菌侵染)、菌核病、疫病     

香草兰细菌性软腐病发生规律研究初报

田间病害调查及系统观察结果表明;香草兰细菌性软腐病在海南省分布较广且周年均可发生。４～１０月份为病害盛发期。高温、多雨、高湿是病害发生发展的重要条件。低温干旱季节发病较轻。植株病残体和株下表土是本病浸染来源。在植株上爬行的昆虫和软体动物是本病菌传播媒介。     

人参、西洋参病害综合防治技术

人参、西洋参病害共有30余种，从发病部位可分为地上部病害、表土中病害和地下部病害。地上部病害主要有黑斑病(斑点病、褐斑病、茎斑病)疫病、炭疽病、白粉病等。表土中病害主要有立枯病、猝倒病、茎腐病等。地下部病害主要有锈腐病、根腐病(细菌侵染)、菌核病、疫病、红皮病等。各种病害大多是真菌侵染，而且各种     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.