提高小麦繁种基地种子质量的措施

小麦是我国重要的粮食作物．在粮食作物中占有主要地位．播种面积和总产均居首位。近年来．随着生产水平提高．小麦产量增长较快．一批批新良种的选育和推广使小麦生产再上一个新台阶．小麦良种的繁育工作随着人民生活水平的提高和商品经济的发展也越来越重要。为保证小麦良种繁育基地的种子生产加工质量．根据国家相关法规标准及管理制度要求．     

棉花新品种推广中的问题及解决方法

针对转基因抗虫杂交棉和常规棉品种繁育和推广中的主要问题 ,提出了六项解决办法 ,强调在保证育种者种子质量的基础上 ,要严把良种繁育过程的五道关 ,保证繁育种子的质量。     

我国棉花良种繁育体制改革探讨

通过对两种良种繁育技术路线的分析比较提出，“育供、场繁”棉花良种繁育新体制。基本内容包括：育种家承担原种生产、保存和向良种场提供原种的任务，各级良种场从育种家手里取得高纯度原种，以保纯防杂为宗旨，只作高倍扩大繁殖，不再进行系圃选择，每年实行以去杂去劣为主体的中喷花混选良种繁育方法。此法科学简便，省工省时，原种生产量大，可使新品种尽快在生产上发挥经济效益。     

我国茶树育种与良种繁育研究进展

我国民间茶树育种的历史,可追溯到唐宋以前,甚至西晋。茶树专业育种,始于本世纪三十年代。五十年代起,我国应用现代育种技术,有计划有组织地开展茶树育种和良种繁育的研究工作,使越来越多的茶树良种在生产上得以应用。三十多年来,我国茶树育种与良种繁育研究取得了较大的进展,先后开展了茶树品种资源的调查、收集、保存和研究,引种驯化,选择育种,杂交育种,多倍体育种,新技术在茶树育种上的应用,茶树良种     

楚雄地区小麦良种混杂退化原因及应对措施

分析造成楚雄地区小麦良种混杂退化的原因主要有生物学混杂、机械混杂、不正确的繁育方法及种子自留串换等,提出了坚持三级良种繁育程序、采用适当的繁育方法、严防机械混杂、使用高质量的种子等切实可行的措施,防止小麦良种混杂退化。     

甜菜育种考察散记

笔者对在国外考察甜菜生产与科研的过程中,以参观、学习、研讨等方式将获得的甜菜育种方面的见闻进行回顾总结,供作参考。主要内容:⑴甜菜育种目标;⑵甜菜育种技术(甜菜雄性不育系选育;加快育种程序;多倍体育种;甜菜品种田间比较试验);⑶甜菜育种的未来(扩展甜菜原料的用途;加强甜菜综合利用;与环境协调发展的甜菜育种;现代甜菜育种技术力求快优);⑷甜菜良种繁育(种子生产;甜菜种子加工;甜菜种子国家标准)。     

甜菜良种繁育体系创新的商讨

针对我国甜菜良种繁育存在的问题及我国入世后的新形势,提出改进甜菜良种繁育体系的主要措施:统一规划,加强管理,规范良种繁育程序和种子市场,加强种子监督和质量检查,保护优良品种的知识产权;试行多种良繁制度,提倡区域性品种,提高区域试验对照种的水准;加强良种繁育基础理论研究,改进良种繁育技术,提高种子繁殖系数和质量等。     

新疆棉花良繁体系滞后的原因及对策思考

近年来 ,常有因棉花种子质量问题发生农民与种子公司的纠分 ,其中就有相当一部分是因良种繁育工作滞后而造成市场上部分棉花种子质量差 ,种子混杂 ,抗性下降 ,种子芽率不达标 ,出苗差 ,影响并阻碍了新疆精准农业和棉花种子产业化的发展进程。1良种繁育工作滞后的原因1 .1良繁技术力量落后。目前新疆各育种单位普遍存在重育轻繁 ,育种部门追求的是看哪个育种单位育出的品种多 ,哪个单位的名气大 ,得到的科研补贴、科研项目就多 ,而对新品种推广重视不足 ,一些新品种只是昙花一现 ,只有名而没有推广面积。种子经营部门甚至棉花生产单位都重引…     

黑龙江工业大麻品种的性别类型、特点及其良种繁育技术

黑龙江省是我国主要的大麻种植和原料生产基地,优良品种的种子繁殖是大麻产业发展的重要环节.本文针对黑龙江省大麻栽培品种的性别类型、品种特征特性,提出了适宜于本地的大麻良种繁殖的种植方式、最佳环境及良种繁育生产技术,旨在为黑龙江新品种选育和大麻良种繁育提供技术支撑.     

冬小麦轮选987生产用种繁育技术

唐山市丰南区常年冬小麦播种面积1.2万hm2,随着国家小麦良种补贴政策的实施,小麦良种的利用率达到了100%,每年需小麦种子200万kg。轮选987作为丰南区的主栽品种,其种子约占需种总量的90%。为保证当地生产用种,防止混杂退化、保证种子纯度、延长推广使用寿命,做好良种繁育是重要的保证措施。由于种子需求量大,为满足生产需要,必须根据该品种的特点与自然条件按科学方法进行繁种。     

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).