小麦籽粒性状的QTL定位

为了明确小麦籽粒性状的遗传控制基础,以γ射线诱变结合花药培养创制的大粒、高蛋白小麦新种质H307及生产上主栽品种郑麦9023创建的含有310个株系的重组自交系为实验材料,利用QTL-ICIMapping V3.3软件构建了包含133对SSR标记的遗传连锁图谱,对千粒重、粒长、粒宽、籽粒面积、周长、粗蛋白和淀粉含量进行QTL分析,结果在两年环境条件下共检测到47个加性QTL和10个QTL富集区,其中6个千粒重QTL,分别位于1D、2B、3D、6D和7A染色体上,单个QTL可解释4.54%~13.14%的表型变异;31个粒形QTL,位于1B、1D、2B、3B、3D、5A、5D、6B、6D、7A和7D染色体上,单个QTL可解释2.90%~15.86%的表型变异;10个粗蛋白和淀粉含量QTL,分别位于1A、1B、4B和6A染色体上,单个QTL可解释3.64%~12.19%的表型变异。2B染色体上检测到1个贡献率较大且能稳定表达的重要染色体区段,该区段包含控制小麦千粒重、粒长、粒宽、籽粒面积和周长的10个QTL。1BL染色体上检测到1个控制籽粒粗蛋白含量的微效QTL,对表型的贡献率为3.64%,与连锁分子标记gwm818的遗传距离为0.22cM,该位点是一个不同于前人研究结果的新位点。     

小麦籽粒蛋白质组分含量的QTL定位

为了给分子标记辅助选择和小麦品质育种提供依据,以小麦杂交组合99G44×京771重组自交系群体(RIL)为材料,采用复合区间作图法对小麦籽粒蛋白质组分含量进行了QTL分析,结果检测出1个与清蛋白含量有关的显著加性效应QAIb-3A,位于3A染色体,位点总贡献率为1.65%;检测出1个与球蛋白含量有关的显著加性效应QGlo-2A,位于2A染色体,位点的总贡献率为7.08%;检测出2个与醇溶蛋白含量有关的显著加性效应QGli-1B和QGli-6D,分别位于1B、6D染色体,位点总贡献率为16.11%;检测出2个与谷蛋白含量有关的显著加性效应QGIu-2D和QGlu-5A,分别位于2D、5A染色体,位点总贡献率为14.71%.     

小麦熟期相关性状的QTL定位分析

抽穗期、始花期和开花期是衡量小麦成熟期的重要指标,对其进行QTL定位并分析其遗传效应,对小麦品种改良至关重要。为了给小麦分子标记辅助选择育种提供参考,本研究以波兰小麦和普通小麦品系中13杂交后代的F8重组自交系为作图群体,构建由A染色体组和B染色体组共14个连锁群构成的遗传连锁图谱,包含115个SSR标记位点,图谱全长822.9cM,标记间的平均遗传距离为7.16cM;利用复合区间作图法在两年的环境中检测到分别位于1A、5A、6A、7A、2B、4B、5B和6B染色体上的8个抽穗期QTL,5个始花期QTL和6个开花期QTL。表型变异解释率分别为10.12%～31.51%、11.98%～19.75%和9.64%～20.27%。无论是抽穗期、始花期或开花期,都在4B染色体上检测出了与其相关的QTL,说明4B染色体与小麦成熟期关系密切。另外,在1A染色体上检测出2个控制抽穗期的QTL,对表型变异的贡献率分别达到28.13%和31.48%,说明1A染色体控制小麦抽穗期的作用较大。本研究检测出多个成熟期相关的QTL与连锁标记间的遗传距离仅0.01cM,近乎共分离,可在育种中直接用于成熟期的分子辅助选择。     

小麦纹枯病抗性QTL分析

小麦纹枯病是世界性的小麦重要病害之一,培育和使用抗病品种是减轻纹枯病危害最经济和有效的手段。为了挖掘更多的小麦纹枯病抗性QTL用于小麦标记辅助育种,本研究构建了CI12633和扬麦158重组自交系群体,采用二代测序方法开发SNP分子标记,并对群体中的94个家系进行基因型分析,构建遗传连锁图;采用牙签接种和病麦粒接种的方法鉴定重组自交系群体纹枯病抗性,进而对小麦纹枯病抗性QTL进行定位。结果显示,构建的遗传连锁图包含3 355个分子标记,遗传距离为2 510.66 cM,共有31个连锁群,均能分配到相应的染色体;在5A(2)、6A、1B、2B、3B、4B、5B、6B(2)、7B、1D、2D(2)、4D和7D染色体共发现16个与小麦纹枯病抗性相关的QTL,单个QTL可解释9.0%～26.8%的表型变异;除了7B染色体的QTL来源于感病品种扬麦158,其余QTL均来自抗病品种CI12633;3B、7D和5A(Chr5A_564101963)染色体的QTL与已有报道一致,其余均为新发现的QTL。发现的QTL和紧密连锁分子标记为今后小麦抗纹枯病分子标记辅助育种以及抗纹枯病基因的克隆提供帮助。     

大穗材料高麦1号/密小穗F_2群体穗长性状的QTL初步定位

为了解小麦穗长性状的遗传特性,并将其应用于分子标记辅助育种,以大穗材料高麦1号/密小穗的292个植株的F2群体为材料,利用SSR标记对穗长进行了QTL定位分析。结果表明,选用500对SSR引物对高麦1号和密小穗两个亲本进行多态性检测,共获得180对在双亲间有多态性的引物,多态性引物检出率为36.0%。利用这180对引物进一步进行F2群体筛选,有96对引物在群体中表现出多态性,占多态性标记的53.3%。利用QTL_IciMapping软件构建出小麦染色体组的8个连锁群图谱,并将96对SSR引物定位到遗传连锁图谱上。图谱全长1 383.29cM,标记间的平均遗传距离15.37cM。平均每个连锁群有11.25个标记,含有标记最多的是4A和6B染色体,各有17个标记,其次是3A和7B染色体,含有9~14个标记,1B和5D染色体含有的标记最少,只有5~7个。共检测出7个与穗长相关的QTL位点,包括6个加性QTL和1个加性+显性QTL。7个QTL的加性效应值均为正值,单个QTL的贡献率为2.04%~15.26%。其中3A染色体上的QTL位点距离其最近标记只有0.58cM,为连锁最紧密的一个位点,并且其加性效应值最大,可解释表型变异的15.26%。因此,3A染色体上存在控制穗长的主效基因。     

小麦BNS雄性不育基因连锁群分析和主效QTLs初步定位

为初步定位小麦温敏雄性不育系BNS中与不育相关的QTL及其所属连锁群,用BNS及其完全保持系郑麦366的F₂为作图群体,建立自交结实率和花粉可育率两个表型BSA池,选用均匀分布在小麦染色体上的710个SSR分子标记,在BSA池中筛选连锁标记,并进行QTL定位,同时用连锁标记引物在BNS DNA中重扩增,扩增产物序列在小麦基因组中进行比对,验证标记所属染色体并分子定位。结果表明,在2对BSA池中共筛选到12个连锁标记,涉及8个连锁群。单标记分析发现,5个连锁标记（Xwmc396、Xwmc517、Xbarc55、Xwmc332和Xwmc752）与不育QTL紧密连锁。用区间分析法分析发现,有2个主效不育QTL,分别为2B染色体上的 qBS1 （紧密连锁Xwmc332和Xbarc55）和7B染色体上的 qBS2 （紧密连锁Xwmc396和Xwmc517）。两个主效QTL的LOD值均大于5,贡献率均大于13%,且显性效应均大于加性效应。     

玉米淀粉QTL定位分析

试验以5M017和5D07为父、母本杂交组配的110株F_2代分离群体为试材,筛选68对多态性较好的SSR引物构建遗传图谱,覆盖1 607.7 cM,平均遗传距离23.64 cM。用完备复合区间作图法(ICIM)对玉米淀粉(总淀粉、直链淀粉、支链淀粉)含量进行QTL分析。结果表明,共检测到17个与玉米淀粉含量有关的QTL,其中,10个与总淀粉含量有关,分布在除第4以外的染色体上,有8个位点加性效应为负值,总淀粉含量增效基因主要来自父本;与直链淀粉含量有关的QTL有5个,分别位于第2、3、6、8、10染色体上,4个位点加性效应为正值直链淀粉增效基因多数来自母本;与支链淀粉含量有关的QTL有2个,位于第3、10染色体上,均表现遗传负效应。位于第10染色体标记区间phi059-umc1432检测到3种淀粉含量相关QTL。     

小麦抗梭条花叶病的分子标记及QTL定位

为了探寻小麦抗梭条花叶病的遗传机制,以外引种质ARz与大面积推广品种扬麦158杂交获得的包含137个株系(F9)的重组自交系群体(RIL)为材料,连续三年利用人工病圃对其进行抗梭条花叶病鉴定,发现株系间抗性存在显著差异;利用SSR标记技术对该群体进行多态性分析,获得97个位点的多态性资料,用JionMap3.0对多态性位点进行遗传作图,共拟合获得了由66个SSR标记位点组成的17个连锁群,涉及2A、2D、3A、3B、3D、5A、7B、7D等8条染色体;使用MapQTL5.0对与群体抗性显著相关的连锁群进行区间作图,结果在2D染色体长臂上检测到1个与小麦梭条花叶病抗性相关的QTL,位于标记Xgwm539~Xgwm608之间,LOD值5.8,LOD值峰距标记Xgwm608 1.7 cM,加性效应值为-0.458,可解释24.7%的表型变异.该抗性基因来源于亲本ARz.这此结果表明,在小麦2D染色体上存在与小麦梭条花叶病抗性相关的位点,标记Xgwm608可以用于抗病性分子标记辅助选择.     

小麦成熟期QTL定位与分析

小麦成熟期对粮食周年丰产具有重要的决定作用。为了给小麦分子标记辅助育种提供可用的分子标记,本研究以人工合成六倍体小麦(Turtur)和T.spelta L.衍生系(Bubo)为亲本创制的包含186个家系的RIL群体(F6)为材料,构建了包含5 301个标记(4 120个DArT标记、621个SNP标记和560个传统DArT标记),总长为2 464cM的遗传连锁图谱,利用Windows QTL Cartographer 2.5软件的复合区间作图法对在3年4点环境下的成熟期性状进行QTL检测,在LOD2.5水平下,共定位到15个QTL,分布于小麦的1A、2B、2D、3A、4A、4B、5B、7A和7B染色体上,可解释4.42～12.67的表型变异。其中在1A染色体上控制小麦成熟期的QTL贡献率最大;4B染色体的1215714-1068877F0-44CG区间内3年3点均检测到的QTL与1215714标记遗传距离为0.01cM,近乎共分离,为下一步分子标记辅助选择的精准性提供了坚实的基础。     

小麦穗部性状和株高的QTL定位及T6VS·6AL易位效应分析

为了发掘新的穗部性状和株高QTL,利用扬麦17与扬麦18杂交后代206个单株组成的F2群体,构建了一个由141个SSR标记组成的全长1005.1cM的遗传图谱。该图谱包括26个连锁群,覆盖15条染色体,标记间平均距离为7.03cM。结合F2和F2:3群体的表型数据,对穗部性状和株高进行QTL分析,利用复合区间作图法检测出15个QTL,分布在2B、2D、4B、5A、5B和7A染色体上,其中4个QTL能够同时在两个世代被检测到,表型变异解释率为1.93%~20.78%,穗长QTLQSl-YY-2D、QSl-YY-5A和株高QTLQPh-YY-4B的贡献率超过10%。根据6VS特异性标记鉴定和表型调查结果,推测扬麦18的6VS上携带有增加穗长和穗粒数的基因,且为部分显性。2B染色体上总小穗数和5B染色体上穗粒数、穗基部结实粒数的QTL增效等位基因及2D、4B染色体上降低株高的QTL增效等位基因均来自扬麦18,表明该品种可作为具有高产潜力的小麦育种材料加以利用。     

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.