黑龙江省不同地区大豆菌核病病原菌分离物的形态学分析

利用PDA培养法从黑龙江省黑河、绥化和佳木斯等3个地区大豆发病田中,共分离和纯化出135个菌核病病原菌分离物,并对菌落的形状、生长速率、菌核重量和子囊盘等形态学特性进行了分析。结果表明:在菌落的形状和生长速率方面,不同地区的分离物群体间差异极显著,同一地区内各个分离物的表现一致性较好;在菌核重量和子囊盘形态特性方面,不同病原菌分离物产生的菌核的数量、大小、重量及子囊盘形态明显不同。不同采样地点的大豆菌核病病原菌菌落的形状和生长速率存在区域专化性,即3个采样地点的菌落形状和生长速率存在明显差异,而菌核重量和子囊盘形态特性不存在区域专化性。     

大豆菌核病菌生物学特性的研究

为有效控制大豆菌核病的发生、蔓延,从采自黑龙江省不同地区大豆菌核病菌中选取5个代表性菌株进行生物学特性的研究.结果表明:大豆菌核病菌菌丝生长的最适温度为20 ～ 25℃,而菌核在15 ～20℃时产生量最多;菌丝适于在中性和偏酸性条件下生长.病菌在PDA和大豆叶片汁培养基上生长较好,菌核的产生则在向日葵叶片汁培养基上最多;有无光照对菌丝生长影响不大,但光照有利于菌核的产生.子囊孢子萌发最适温度为25℃;萌发最适pH为7～8;大豆汁、向日葵汁和油菜汁可促进子囊孢子的萌发;有无光照对子囊孢子萌发无显著影响.不同地区大豆菌核病菌由于生态条件的不同,菌核萌发形成子囊盘能力和病原菌的致病力也存在差异.     

大豆菌核病菌生长特性及抗药性初步测定

采用单菌核分离法得到大豆菌核病菌,利用菌丝生长速率法测定了7株大豆菌核病菌的生物学特性及对多菌灵和腐霉利的抗药性.结果表明:供试菌株菌丝生长的最适温度是15～20℃,而菌核的产生则在15℃左右最多;大豆菌核病菌丝生长最适的环境为中性和偏酸性;不同菌核及病残体埋入土壤不同深度后越冬处理,病残体上菌丝不能越冬,而菌核能够越...     

华南3省（区）水稻纹枯病菌的生物学性状与致病力分化研究

 为了探明华南地区水稻纹枯病菌的生物学性状、致病力分化与菌株地理来源之间的关系,为该病害的防治提供依据,从我国华南3省（区）广东、广西和海南的33个县（市）采集水稻纹枯病标本,在分离到335个水稻纹枯病菌菌株的基础上,对它们的培养性状（菌丝生长速率、菌落颜色、菌核数量）、菌丝融合群、菌丝细胞核数目以及致病力分化进行了研究。结果表明,菌株菌丝生长速率可划分为慢、中、快3种类型,菌株数分别为3株（0.90%）、136株（40.60%）和196株（58.50%）;产生菌核的数量可划分为4种类型,即无菌核或极少形成菌核、菌核量少、菌核量中等和菌核量多,各有4株（1.19%）、59株（17.61%）、238株（71.04%）和34株（10.15%）。菌株融合群测定结果表明,所有供试菌株均属于立枯丝核菌（Rhizoctonia solani）AG-1融合群的ⅠA亚群,即AG-1 ⅠA。从中随机选取50个菌株进行菌丝细胞核染色,结果显示,水稻纹枯病菌菌丝的细胞核数目介于7～13个。对其中270个菌株的致病力测定结果表明,所有供试菌株可划分为中等致病力和强致病力2个致病型,分别为208株（77.04%）和62株（22.96%）,未发现弱致病力菌株。综合分析表明,所测菌株的致病型与菌丝生长速率及菌核产生数量各异,表现出较大的多样性。     

热激对玉米大斑病菌生长和发育的影响

通过对玉米大斑病菌进行热激处理,观测热激对病菌孢子萌发、菌丝生长速度、菌落形态、菌丝形态等方面的影响。结果表明:热激处理对分生孢子萌发率的影响与热激温度有关,42℃热激促进孢子萌发,45℃热激对孢子萌发没有显著影响,48℃热激则会显著抑制孢子萌发;42℃～48℃热激处理会降低病菌的菌落生长速度,热激温度越高菌落生长速度越慢;42℃～48℃热激对菌丝形态、分生孢子形态、菌落颜色和菌落形态均无明显影响,但菌丝细胞中的内容物减少,有时出现内容物缺失的菌丝细胞。     

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.     

戊唑醇对油菜菌核病菌作用机制的探讨

为探明戊唑醇对油菜菌核病的防治效果及作用机制,采用生物测定方法,研究戊唑醇的室内毒力、油菜菌核病菌(Sclerotinia sclerotiorum)的菌丝干重、菌丝蛋白质含量、菌核萌发、菌核致病力和菌丝体细胞膜电导率。结果表明:戊唑醇对油菜菌核病菌具有极强的抑菌作用,EC50和EC90值分别为1.3μg/mL和11.2μg/mL;用戊唑醇处理后,菌丝体干重差异显著,蛋白质含量、菌核萌发率和致病力均随处理浓度的提高而降低;戊唑醇对菌丝体电导率无影响,但对菌丝体的生长有抑制作用。表明戊唑醇通过抑制菌丝干重、菌核萌发率、蛋白质含量和致病力而控制病害发生。     

黑龙江省大豆新品系抗灰斑病情况分析

对1999～2001年黑龙江省各大豆育种单位育成的211份大豆新品系进行大豆灰斑病菌的混合菌种接种鉴定,三年的鉴定结果是,表现高抗的只有1份,表现抗病的39份,占供试材料的18.48%,中抗的78份,比例是36.97%,表现感病的93份,比例为44.08%.对来自7个生态区的大豆品系抗性分析结果表明,各生态区供试材料中,抗病品系比例由高到低依次为:八一农大-绥化-哈尔滨-佳木斯-北安-九三局-黑河;中抗品系比例由高到低依次为哈尔滨-佳木斯-绥化-北安-九三局-八一农大-黑河;感病品系比例由高到低依次是黑河-九三局-北安-绥化-佳木斯-哈尔滨-八一农大.     

花生果壳褐斑病的研究

花生果壳褐斑病是我国花生主产区发生的一种新病害。本试验对该病的病原菌进行了分离培养,细胞核染色及菌丝融合实验,明确了该病原菌的分类地位,菌丝及菌落生长特点,细胞核数目及其与叶部菌核病原菌的融合状况。确定了该病菌属于双核丝核菌,即禾谷丝核菌（Rhizoctonia cerealis）,与花生叶部菌核病菌（Rhizoctonia solani）不能发生菌丝融合,属于丝核菌的不同种群。     

油菜菌核病拮抗细菌的筛选和高效菌株的鉴定

从油菜根际和叶围分离得到320个细菌分离物,在马铃薯葡萄糖琼脂培养基上的拮抗实验中,18个分离细菌表现对油菜菌核病菌不同程度的拮抗作用,其中Y1菌株对油菜菌核病菌菌丝的生长具有明显的抑制作用.对Y1进行油菜离体叶片、温室盆栽和田间小区接种实验,该菌均表现对油菜菌核病明显的防病效果;在温室盆栽试验和田间小区试验中,防病效果达到92%.经过鉴定,Y1菌株为枯草芽孢杆菌.     

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.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

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.     

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.     

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.