一个大穗型小麦-黑麦异代换系的细胞学和SSR鉴定

为了深入研究大穗型小麦的遗传基础,利用细胞学和SSR方法对从普通小麦与六倍体小黑麦杂交后代中选育的大穗型小麦-黑麦材料7-25进行了鉴定.结果表明,品系7-25的根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期I(PMC MI)绝大多数细胞内可观察到21个二价体,平均染色体构型2n=20.94Ⅱ 0.11Ⅰ,它与中国春杂种F1的多数花粉母细胞染色体构型为2n=20Ⅱ 2Ⅰ,因此表明品系7-25 是一个小麦-黑麦的二体异代换系.使用位于黑麦1R～3R、5R～7R染色体上的黑麦特异的20对SSR引物,其中有2对引物SCM268和SCM120能在7-25品系中稳定地扩增出黑麦特异染色体片段.SCM268、SCM120分别位于黑麦5R染色体的短臂和长臂上.综合细胞学和SSR分析结果,进一步确定品系7-25为小麦-黑麦5R代换系.     

普通小麦与偏凸山羊草代换系的细胞学和RAPD鉴定

为了解偏凸山羊草与普通小麦杂种后代抗白粉病种质BC5-2的遗传组成,对其进行了细胞学和RAPD鉴定。结果表明,BC5-2根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期(PMC M)染色体构型为2n=21。经核型和C-分带分析初步证明BC5-2为偏凸山羊草的双代换系,其中一对为偏凸山羊草的2MV染色体,另一对为6MV染色体,在BC5-2中被代换的小麦染色体是1B和6A染色体。对BC5-2及其亲本进行RAPD分析,在100个随机引物中有2个引物在BC5-2中扩增出偏凸山羊草的特异DNA带,它们分别记为S2011550、S20031000,进一步证明BC5-2是一个普通小麦与偏凸山羊草的双代换系。     

小麦-中间偃麦草代换系中233的分子细胞学鉴定

为了从小麦-中间偃麦草衍生后代中获得具有优良性状的新种质,利用细胞学和分子标记技术对中间偃麦草衍生系中233进行鉴定。结果表明,中233的根尖细胞染色体数为2n=42,花粉母细胞减数分裂中期Ⅰ的染色体通常配成21个二价体。以中间偃麦草基因组DNA为探针、中国春基因组DNA为封阻进行基因组原位杂交(GISH)分析发现,中233含有2条中间偃麦草染色体和40条小麦染色体,在减数分裂中期I,两条中间偃麦草染色体可以正常配对。利用D基因组特异探针pAs1进行荧光原位杂交(FISH)分析发现,中233缺少了一对小麦的2D染色体。分子标记鉴定进一步表明,中233的1对小麦2D染色体被中间偃麦草染色体所代换。说明中233是一个细胞学稳定的小麦-中间偃麦草二体代换系,初步推断其可能携带有中间偃麦草的优异基因。     

大麦胞质小麦

本文报导了新近我们从栽培大麦×普通小麦属间回交后代中获得的自变可育异质小麦后代的细胞学和生化学分析结果,异质小麦F_1体细胞染色体数变动在41～43,其中整倍体(2n=42)的频率为93.95％,F_1植株花粉母细胞在减数分裂中期Ⅰ时染色体的构型为n=21Ⅱ和n=20Ⅱ+2Ⅰ,示遗传型稳定。2n=42植株的染色体N——分带,其带型类似普通小麦,采用叶绿体组分Ⅰ蛋白等电聚焦电泳分析表明,杂种细胞质的遗传主要来自母本大麦,证明该异质小麦,就是大麦胞质小麦。大麦胞质小麦的表型,为完全自交可育,植株生长正常,早熟、千粒重高,在小麦改良中,有直接应用价值。     

大麦2H染色体对小麦农艺和品质特性的影响

为了研究2 H染色体对小麦农艺和品质特性的影响,测定了普通小麦中国春(CS)、栽培大麦Betzes及其杂种衍生的二体异附加系CS 2H和3个异代换系2H/2A、2H/2B、2H/2D的农艺性状及籽粒硬度、蛋白质组成、淀粉特性.结果表明,2H附加系和代换系的农艺性状比CS都有不同程度的改善,但不育小穗数增加,不育率提高,以2H/2A的不育率最高(40.4%).籽粒硬度仅2H附加系表现超亲,三个代换系则介于双亲之间.含2H染色体材料的蛋白质、总氨基酸、苏氨酸和赖氨酸含量、沉淀值均表现超亲遗传,尤以2H/2A的超亲优势最大.3个异代换系的直链淀粉含量均低于双亲,以2H/2A的含量最低;2H/2B的降落值介于双亲之间,其余均超亲,以2H/2A最高.三个代换系的峰值粘度、最终粘度都超亲,稀懈值介于双亲之间.2H/2A在这些淀粉品质指标中表现出了最好的遗传正效应.     

λDNA导入普通小麦诱导的雄性不育系的初步研究

为明确λDNA导入普通小麦中国春诱导的λD型雄性不育系的育性表现及其花粉母细胞减数分裂过程中的染色体行为变化,对受体中国春、不育系、普通小麦LM14及其杂种后代进行了室内考种和细胞学观察。结果表明,λD型不育系不育度高,受体中国春对其具有较好的保持作用,LM14对其较好的恢复作用。花粉母细胞(PMC)减数分裂观察发现,受体中国春的PMC染色体异常率为0.91%,λD型不育系的PMC染色体异常率为2.04%,染色体异常类型主要有染色体落后、单价体、染色体桥、微核等。     

普通小麦与Elymus rectisetus衍生后代的细胞遗传学和形态学研究

披碱草（Elymus rectisctus,以下简写为E．rectiselus)具有二倍性无融合生殖特性,为了获得小麦-E．rectisetus稳定的异附加系或异代换系,对(小麦-E．rectiselus)BC2F2衍生后代的细胞学和形态学进行了研究。结果表明,在BC2F5～BC2F7镜栓的单株中,体细胞染色体数目在22～50条之间,其中42条和44条染色体所占的比例最大,分别占鉴定植株总数的38．0％和35．9％。三个2n=42=21″的稳定株系与普通小麦Fukuhokomugi杂交F1的花粉母细胞染色体构型为2n=18″ 6′,表明有三对E．rectiselus染色体代换到普通小麦中;三个2n=44=22″的稳定株系与Fukuhokomugi杂交F1的花粉母细胞染色体构型为21″ 1′,表明它们为二体异附加系。此外,衍生后代的形态学特征趋向于普通小麦。     

盐胁迫对小麦代换系光合性状的影响及染色体效应研究

为了选育小麦耐盐基因型,以中国春-Synthetic 6x小麦染色体代换系及其亲本为材料,设置对照(0mmol·L~(-1) NaCl)和盐胁迫(150mmol·L~(-1) NaCl)2个处理,通过测定不同处理条件下代换系幼苗比叶重、叶绿素和类胡萝卜素含量及光合速率的变化,探讨盐胁迫对小麦代换系幼苗光合性状的影响,并对其调控相关特性的基因进行染色体定位。结果表明,盐胁迫导致多数小麦代换系叶绿素和类胡萝卜素含量、比叶重、光合速率降低;盐胁迫条件下,Synthetic 6x的2D染色体上可能存在诱导比叶重升高的基因,1A、5A、7A、2B、3B、5B、6B和6D染色体上可能存在诱导叶绿素含量增加的基因,1A、4A、7A和5B染色体上可能存在诱导类胡萝卜素含量增加的基因,1A和7D染色体上可能存在诱导幼苗光合速率增强的基因,即Synthetic 6x的1A染色体上可能存在调控光合特性的关键基因。     

利用细胞学和RAPD技术鉴定抗条锈病小滨麦易位系

为了了解来自八倍体小滨麦与普通小麦杂种后代的小滨麦种质系山农0096的染色体构型和抗锈性,在农艺性状综合评价的基础上,对该系进行了细胞学和RAPD鉴定。结果表明,山农0096对条锈病免疫,其根尖细胞染色体数为2n=42,花粉母细胞减数分裂中期 (PMCMI)染色体构型为2n=21 ;与小麦亲本的杂种F1PMCMI染色体构型平均值为2n=19 1 ;100个多聚体核苷酸随机引物中,有3个引物在山农0096中扩增出滨麦草的特异DNA带,它们分别记为S241250、S38750、S42640,初步确定山农0096是一个小滨麦易位系。     

几类异质小麦雄性不育系育性恢复的染色体行为研究

为了研究异质小麦雄性不育系减数分裂中期Ⅰ与后期Ⅰ的染色体行为及与育性恢复的相关性,以几类异质小麦雄性不育系为母本,用常规品种(系)作为父本与其杂交,调查了杂种F1减数分裂中期Ⅰ单价体频率与后期Ⅰ染色体变异率及自交结实率之间的相关性.结果表明:(1)花粉母细胞减数分裂中期Ⅰ单价体频率与后期Ⅰ染色体变异率呈显著正相关,后期Ⅰ染色体变异率与自交结实率呈负相关,但不显著;(2)相同异质不育系与相同或不同品种杂交时减数分裂中期Ⅰ单价体频率与后期Ⅰ染色体变异率及结实率差异不显著;(3)不同异质不育系与相同或不同品种杂交时减数分裂中期Ⅰ单价体频率与后期Ⅰ染色体变异率差异性较为显著,但减数分裂中期Ⅰ单价体频率与结实率差异性不显著;(4)异质小麦中,异源胞质影响染色体变异,但核基因是调控的关键因素.     

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.     

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.