黑龙江省马铃薯晚疫病生理小种的类型与分布状况研究

通过对黑龙江省5个地区12个县市的马铃薯晚疫病菌生理小种的鉴定,鉴定出黑龙江省马铃薯晚疫病菌生理小种有14种类型,分别为0号、1号、2号、3号、4号、5号、7号、9号、11号、1 2号、2 3号、2 4号、3 4号、1 2 3 4号,其中分布最为普遍是0号、4号和11号生理小种。与60年代相比,新出现的有10个小种:3号、5号、7号、9号、11号、1 2号 2 3号、2 4号、3 4号和1 2 3 4号。     

云南省马铃薯主要品种晚疫病抗性评价

为了解云南省马铃薯主要品种的晚疫病抗性,利用云南省马铃薯晚疫病菌优势生理小种(1.2.3.4.6.7.9.10.11)和超级生理小种(1.2.3.4.5.6.7.8.9.10.11)对云南省马铃薯主要品种进行抗性评价。结果表明,在供试的20个品种中,没有对2个供试生理小种表现高抗的品种;对优势生理小种,‘云薯304’、‘云薯401’、‘镇薯1号’和‘紫云1号’4个品种表现抗病,‘合作88’和‘云薯505’表现中抗;对超级生理小种,仅‘云薯304’和‘云薯401’分别表现抗病和中抗。云南省种植的马铃薯主要品种中‘会-2’、‘丽薯6号’、‘宣薯2号’和‘青薯9号’对优势小种均已丧失抗性,‘合作88’仅表现中抗。生产上迫切需要晚疫病抗性强且抗性持久的马铃薯新品种,以减少晚疫病造成的产量和经济损失。     

哈尔滨市马铃薯晚疫病菌生理小种的类型

马铃薯晚疫病是由致病疫霉菌[Phytophtora infestans(Mont.)de Bary]引起的毁灭性病害,近年来,该病害在哈尔滨市连年发生,危害日趋严重。本研究对2010年从哈尔滨市采集62个马铃薯晚疫病菌分离物进行了生理小种鉴定。结果表明,在62个分离物中,共有14个小种类型,以1.3.4.7.8.10.11小种为主,出现频率为33.87%,其次是小种1.3.4.7.8.和1.3.4.7,出现频率分别为14.52%和12.90%,没有鉴定出单基因小种。这充分说明,哈尔滨市致病疫霉菌毒力结构呈多样性,具有高度的复合性。     

中国马铃薯晚疫病菌生理小种研究进展

由致病疫霉(Phytophthora infestans)引起的晚疫病是马铃薯生产中最具毁灭性的病害,生理小种是晚疫病菌重要的表现型之一,其组成与变异直接关系到马铃薯晚疫病的发生与流行。对马铃薯晚疫病菌生理小种的研究进展进行了综述,分析了中国晚疫病菌生理小种的多样性及生理小种毒力基因的复杂性,并指出了目前中国晚疫病菌生理小种研究存在的问题,为今后马铃薯晚疫病菌生理小种的研究提供思路。     

马铃薯晚疫病菌生理小种的异质性研究

在马铃薯晚疫病生理小种的鉴定中 ,经常出现结果不合理的现象 ,这时应通过单基因和复合基因鉴别寄主的发病情况反复相互验证 ,并增加重复次数 ,才能得出正确的结论。试验证实马铃薯晚疫病菌的生理小薯不是异质的 ,而是同质的     

利用晚疫病菌无毒基因瞬时表达技术鉴定马铃薯抗病基因

由Phytophthora infestans引起的晚疫病是马铃薯的毁灭性病害。明确现有马铃薯品种或育种材料含有的晚疫病抗病基因,对于抗病育种和合理利用不同抗病基因防治马铃薯晚疫病具有重要意义。根据"基因对基因"学说,马铃薯无毒基因与抗病基因产物互作会产生典型过敏反应(HR)。理论上利用病原菌无毒基因可以鉴定马铃薯是否含有相应抗病基因。本研究尝试利用农杆菌注射技术,在马铃薯叶片中瞬时表达晚疫病菌无毒基因(Avr),根据过敏反应发生情况,进而推断马铃薯品种/育种材料所含相应抗病基因(R)。研究结果显示:适合马铃薯瞬时表达的农杆菌浓度为0.5(OD600),马铃薯材料农杆菌瞬时表达存在明显的基因型和叶龄依赖性,充分展开的幼嫩叶片适合农杆菌瞬时表达。Avr1,Avr2,Avr3a和Avr4在含有相应抗病基因的马铃薯鉴别寄主上瞬时表达能够产生HR,表明无毒基因注射鉴定结果是可靠的。无毒基因注射鉴定结果与抗病基因特异引物PCR扩增结果在不同基因型材料上有时并不一致,反映了这两种方法各有局限性,若能将这两种方法结合使用,则会提高鉴定结果的准确性。     

西南地区玉米大斑病菌生理小种鉴定

2008～2010年对采自西南地区的玉米大斑病标样经过单孢分离、纯化,共获得146个菌株。通过Ht单基因鉴别寄主进行生理小种鉴定,共鉴定出9个生理小种,分别为0、1、2、3、12、1N、2N、3N、N。0号小种占鉴定菌株的62.33%,为优势小种,其次为1号小种,占鉴定菌株15.07%。毒性频率分析表明,所有供试菌株对Ht1抗性基因的毒性频率最高,为20.99%;对Ht3抗性基因的毒性频率最低,为1.36%;对Ht2和HtN抗性基因的毒性频率分别为13.01%和9.57%。目前,西南地区玉米大斑病生理小种分化明显,并且产生了新的生理小种,对玉米生产存在潜在威胁。     

我国部分麦区 2011-2012年小麦白粉病菌小种及毒力分析

为了解我国部分春麦区和冬麦区小麦白粉病菌小种和毒力状况,2011-2012年对采自辽宁、黑龙江等东北春麦区及山东、湖北、四川等冬麦区的小麦白粉病菌标样进行生理小种鉴定和群体毒性频率测定.结果表明,2011-2012年东北春麦区优势小种均为411号小种,而山东、湖北等冬麦区的优势小种为377号小种,四川麦区的则为317号小种.小麦白粉病菌毒性基因V3b、V5、V7、V8、V1+2+9、V17毒力频率较高(＞90.0％),而V2、V4a、V4b、V12、V13、V16、V18-V23、V5+6毒力频率较低(＜31.4％),表明目前含有Pm2、Pm4a 、Pm4b、Pm12、Pm13、Pm16、Pm18-Pm23、Pm5+6等抗病基因的品种在我国部分麦区育种中仍有较高的利用价值.     

陇南不同区域内两个小麦品种上条锈菌群体的毒性分析

为了解陇南越夏区内小麦品种铭贤169和小偃22上条锈菌的毒性组成及遗传多样性,利用19个中国小麦条锈菌鉴别寄主对陇南4个越夏区内两个小麦品种上采集分离的236个单孢菌系进行毒性分析。结果表明,陇南越夏区小麦条锈菌群体毒性结构复杂,不同区域间毒性多样性存在显著差异。在236个菌系中,198个被鉴定为13个已知小种(致病型),其中CYR32和CYR33为优势小种,频率分别高达30.51%和29.24%;其他11个小种(致病型)主要是水源11类群和Hybirde 46类群,频率较低,不足5%。另外38个菌系是能稳定侵染贵农22的新菌系,可归为两类,分别具有CYR32和CYR33致病特点,频率分别为7.20%和8.90%。所以当前抗病育种应以CYR32和CYR33为主,兼顾水源11、Hybirde 46、V26等其他致病类群。在铭贤169上,条锈菌群体毒性Nei’s基因多样性指数和香农信息指数分别为0.20和0.33,在小偃22上分别为0.17和0.28,说明铭贤169上的条锈菌群体毒性多样性高于小偃22,这种差异可能是寄主的定向选择作用和环境条件共同作用的结果。     

湖北恩施地区马铃薯晚疫病病菌生理小种的组成及分布

<正>马铃薯晚疫病菌的生理小种纷繁复杂,许多垂直抗性品种由于新小种的产生,而使其抗病性丧失殆尽,这种情况在很大程度上限制我们利用抗病品种来防病.小种的问题历来是植物病理学家所关注的问题.了解马铃薯产区晚疫病菌小种的发生、组成及变化规律,对研究晚疫菌和马铃薯之间的相互关系,对有针对性的引进、培育和推广抗病品种,更好地发挥抗病品种的作用是必要的.恩施地区的气候特点在西南山区具有代表性,本地是晚疫病的重病区.本工作对该地区的晚疫病菌生理小种做了调查,并进行了鉴定.     

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.     

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.