油菜菌核病菌对腐霉利的抗性诱变及抗药菌株的生物学特性

从江苏省镇江市和扬州市采集菌核病植株的茎,从中分离获得油菜菌核病菌（Sclerotinia sclerotiorum）单菌核菌株。32个野生型菌株药剂敏感性（EC50）频率分布数据显示,病菌对腐霉利的敏感基线EC50值为0.1981 ± 0.0220 µg/mL,MIC（最小抑菌浓度）值为 1.1 ± 0.1595µg/mL。实验未发现田间抗腐霉利菌株。通过室内紫外线和药剂诱导,获得多株高抗腐霉利突变体（EC50>1000µg/mL）。这些抗性突变株经转管培养5~20代后抗药性稳定。它们对同类药剂异菌脲和有机磷类甲基立枯磷也表现高抗,但对苯并咪唑类多菌灵敏感。与野生型敏感菌株相比,抗腐霉利突变株菌丝生长较慢,对油菜茎杆和叶片的致病力均较弱。     

油菜菌核病菌抗腐霉利菌株的生理生化特性及抗药机制初步分析

通过室内紫外线和药剂诱导,获得多株高抗腐霉利油菜菌核病菌(Sclerotiniasclerotiorum)突变体。与野生亲本菌株相比,抗性突变株(EC50800μg/mL)在高糖(40g/L蔗糖)和高盐(5g/LNaCl)培养基上生长缓慢,表明对高渗透压比较敏感;菌丝相对电导率较高,显示细胞膜透性增大,胞内电解质渗出较多。试验还发现,在含药培养液中,亲本菌株菌丝内甘油大量合成和积累,增加462.45%,而抗药突变株甘油含量仅稍有增加或有所下降,说明抗腐霉利突变株对外界渗透压的调节能力较低。根据已报道组氨酸激酶(HK)基因序列设计特异引物,经PCR扩增和测序,获得油菜菌核病菌HK基因保守区域序列1605bp。抗、感腐霉利菌株HK基因保守区域在第45位、第81位和第625位碱基不同,但编码的氨基酸一致。因此,油菜菌核病菌对腐霉利的抗性及抗药菌株的高渗敏感性与HK基因保守区域碱基突变无关。     

橡胶树割面棕榈疫霉条溃疡防控药剂的筛选

由疫霉菌侵染引起的割面条溃疡病是我国橡胶生产中的重要病害。本研究采用菌丝生长速率法对分离自海南省儋州市的棕榈疫霉病菌HNRPP02进行了14种杀菌剂的室内毒力测定。结果表明：杀毒矾(56%代森锰锌·8%噁霜灵WP)、甲霜灵(35%甲霜灵ZGF)、阿米西达(25%嘧菌酯SC)和安克(50% 烯酰吗啉WP)的EC50最小，抑菌效果最好；霜霉威盐酸盐(66.6 %霜霉威盐酸盐AS)的EC50最大，抑菌效果最差。建议橡胶树种植中使用56%代森锰锌·8%噁霜灵WP、35%甲霜灵ZGF、25%嘧菌酯SC和50%烯酰吗     

大豆疫霉对甲霜灵敏感性的遗传与变异

通过平板法,在含甲霜灵1.0μg·mL-1的CAM平板上测定了分离于不同地区的5个大豆疫霉菌和以Ps411-4为亲本的无性后代、有性后代对甲霜灵敏感性的遗传.结果表明:分离自不同地域的菌株对甲霜灵的敏感性存在差异,供试菌株对甲霜灵的敏感性在无性单孢后代无显著变异,而在50个自交有性后代中,上述浓度对其菌丝生长的抑制率分布范围为70.2%～96.8%,与亲本存极显著差异,其中5株高于亲本,4株低于亲本,41株与亲本相似.表明大豆疫霉对甲霜灵的敏感性同样在无性后代稳定遗传而在有性后代发生变异.结果提示,供试大豆疫霉菌株中上述性状可能由细胞核杂合基因控制.     

马铃薯晚疫病病菌对四种杀菌剂的交互抗性

通过测定甲霜灵敏感菌株和抗性菌株对甲霜灵、恶霜灵、霜脲氰、薯瘟锡的抗药水平和抗药类型以确定致病疫霉对此 4种内吸性杀菌剂的交互抗性关系。结果表明 ,致病疫霉对甲霜灵、恶霜灵、薯瘟锡三者间具有正交互抗性 ,此 3种药剂与霜脲氰间无交互抗性关系     

油菜菌核病菌对多菌灵的抗药性

从江苏句容市丘陵山区从未施用多菌灵（MBC）的白菜型油菜苗核病株上，采集了49个Sclerotiniasclerotiorum野生菌株，MBC抑制这些菌株的菌丝生长，平均EC50为0．2198±0．1083μg／ml，最低抑制生长浓度（MIC）值为5．0μg／ml。从镇江农科所油菜育种试验田中采集的S．selerotiorum菌核标样中，发现6个抗MBC的抗性菌株，其EC50值均大于2000μg／ml。抗性菌株对离体油菜叶片的致病力与野生的敏感菌株没有差异。油菜叶片经1000μg／mlMBC溶液浸渍后，敏感菌株对其不能侵染，而抗性菌株对这些叶片的致病力与对未浸药叶片的致病力无明显差异。     

防治大豆疫霉根腐病的药剂筛选

采用实验室测定和温室盆栽方法研究了8种杀菌剂对大豆疫霉菌(Phytophthora sojae)菌丝生长和繁殖的影响及它们对大豆疫霉根腐病的接种防治效果。结果表明,50%烯酰吗啉可湿性粉剂、97%甲霜灵可湿性粉剂和58%甲霜灵锰锌可湿性粉剂对大豆疫霉菌的菌丝生长和繁殖具有很好的抑制作用,该3种药剂能够明显抑制菌丝生长,抑制中浓度(EC50)值依次为0.1208μg/mL、0.1563μg/mL和0.3603μg/mL。浓度为10.0μg/mL时,对孢子囊形成和萌发的抑制率均为100%,对卵孢子形成抑制率分别为64.5%、59.5%和55.0%。接种防治试验结果显示,以上3种药剂喷药后7d防效依次为73.4%、68.8%和60.5%,其余的5种杀菌剂防治效果相对较差。     

紫外线对大豆疫霉菌的诱导变异作用

为明确紫外线对大豆疫霉菌的诱导突变作用,研究了紫外线诱变的突变菌株的菌落形态、菌丝生长速率、菌丝形态、卵孢子形态、产孢能力、同宗配合能力、致病力和抗药性的变异情况.结果表明,大豆疫霉菌突变菌株菌落形态、菌丝生长速率、菌丝和卵孢子形态以及同宗配合能力都发生显著变异,游动孢子产孢量和致病性明显降低.虽未发现对甲霜灵产生抗性的突变菌株,但出现了对甲霜灵敏感性增强的突变菌株.说明紫外线辐射可导致大豆疫霉菌控制生物学性状和致病性的基因发生变异,紫外线可能是引致大豆疫霉菌变异的因素之一.     

海南芒果炭疽菌对多菌灵的抗药性测定

从海南不同地区采集芒果炭疽菌（Colletotrichum gloesporioides Penz.）进行多菌灵抗性检测。敏感性测定结果表明：7 个地区共 23 个菌株中,有 2 个地区的 5 个菌株表现出高度抗药性,在含 1 200 μg/mL 多菌灵的 PDA培养基上菌丝生长良好,EC 50 值为 520.95~746.26 μg/mL。抗性菌株对苯并咪唑类其它杀菌剂如噻菌灵和甲基托布津测定表明,苯并咪唑类杀菌剂之间存在正交互抗药性;对咪鲜胺则表现敏感。连续无毒培养 8 代后,5 个菌株仍可在 1 200 μg/mL 多菌灵的培养基上生长,抗性水平保持不变。通过致病力及孢子萌发对抗药菌株的适合度进行测定,抗药性菌株的致病能力和孢子萌发率无明显变化,表现很高的适应能力,说明这类菌株在田间有很强的竞争力。     

大豆疫霉病菌对四种杀菌剂的敏感性测定

2008年从黑龙江省15个大豆产地土壤中分离获得21份大豆疫霉(Phytophthora sojae)菌株,采用菌落生长速率法测定了21份Phytophthora sojae菌株对4种杀菌剂的敏感性.结果表明:甲霜霜霉、甲霜锰锌、霜脲锰锌和三乙膦酸铝对21个菌株的EC50值分别分布在0.442～4.833、1.005～6.691、2.928～21.651和61.394～262.384 μg·mL-1之间,均值分别为1.242±0.584、3.141±0.814、11.433±2.460和146.289±27.034 μg·mL-1,大豆疫霉病菌对甲霜霜霉、甲霜锰锌、霜脲锰锌和三乙膦酸铝的敏感性高;甲霜霜霉、甲霜锰锌、霜脲锰锌和三乙膦酸铝分别对组成连续单峰频次分布的敏感性菌株的EC50均值为0.966、3.141、11.343和146.289 μg·mL-1,可分别作为大豆疫霉病菌对甲霜霜霉、甲霜锰锌、霜脲锰锌和三乙膦酸铝的敏感性基线.因此黑龙江省大豆疫霉菌对甲霜霜霉、甲霜锰锌、霜脲锰锌和三乙膦酸铝敏感,未产生抗药性.     

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.     

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.     

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.     

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.     

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).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

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.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).