水稻品种五丰占2号的白叶枯病抗性遗传分析

研究了五丰占2号的白叶枯病抗性遗传及在回交世代中的抗性表现。结果表明,用白叶枯病菌株浙173（Ⅳ型）接种,五丰占2号表现中抗,IRBB5表现抗;五丰占2号的白叶枯病抗性受微效多基因控制,基因效应分析表明,该性状符合加性-显性模型,以加性效应为主;隐性主效基因xa5控制的IRBB5对白叶枯病菌株浙173的遗传符合隐性主基因的分离比。对白叶枯病菌株浙173的抗性反应与xa5基因的PCR检测结果一致。在五丰占2号2/IRBB5 B1F1群体中,基因型Xa5Xa5与Xa5xa5的分离比为1∶1;在五丰占2号2/蜀恢162 B1F1群体中,白叶枯病抗性达到五丰占2号水平的植株数占群体总数的68.3%。如果要将IRBB5中的xa5基因与五丰占2号的微效基因聚合,用五丰占2号回交1次是必要的。     

宁麦9号×镇麦168小麦F2群体产量相关性状的遗传模型分析

为给小麦遗传育种中产量性状改良提供参考,利用相关性分析和植物数量性状主效基因与微效多基因混合遗传模型对(宁麦9号×镇麦168)F₂代162个单株的有效穗数、株高、穗长、总小穗数、穗粒数以及单株粒重进行了联合分离分析。结果表明,该群体农艺性状均属于受多基因控制的数量性状,其中有效穗数和单株粒重仅受微效多基因调控,株高和总小穗数符合“两对加性-显性-上位性主基因”+“加性-显性多基因”混合遗传,而穗长和穗粒数则符合“两对加性主基因”+“加性-显性多基因”混合遗传。株高、穗长和总小穗数3个性状的主基因遗传力分别为64.98%、51.22%和47.12%,可能存在效应较大的QTL。     

小麦ARz抗纹枯病的QTL定位研究

纹枯病在我国已成为影响小麦高产、稳产的主要病害之一。为了确定小麦纹枯病抗性基因的位点和数量，本文以单粒传(SSD)方法构建了ARx和扬麦158杂交的F6代重组自交系(RIL)的遗传群体共137个单株，分别在2002和2003年用牙签法和沟带接菌法进行了3次纹枯病抗性鉴定。初步研究结果表明．小麦纹枯病抗性是由主效基因和微效多基因共同控制的。在2D、3A、3B、3D、7D等5条染色体上分析了42个SSR引物．共49个位点．结合回归分析找到10个SSR分子标记。综合本项目组先前分析的48个SSR标记住点．分别对2、3、7同源群使用Map Manager QTXbl7建立了14条连锁区段，并用区间作图法检测到与小麦纹枯病抗病相关的6个QTLs，位于2D、3D、3B和7D上．单个位点可分别解释表型变异方差的9．0％、7．0％、7．0％、9．0％、14．0％和8.0％。初步认为在7D上有一个抗小麦纹枯病的主效QTL。     

玉米孤雌生殖单倍体诱导性状的遗传分析

运用主基因-多基因混合遗传模型理论,对构建的玉米常规自交系与单倍体诱导系杂交组合群体A(四-287×Y11)和两个单倍体诱导系杂交组合群体B(Y6×Y11)的F2世代的单倍体诱导性状的遗传进行研究。结果表明,群体A的单倍体诱导性状遗传由两个主基因控制,表现加性-显性效应,遗传率达91.27%;群体B检测到1个主基因,表现加性-显性效应,遗传率为38.86%,群体B的诱导率遗传主要由主基因和多个微效基因共同作用。     

低磷土壤条件下玉米磷吸收和利用效率的混合遗传分析

运用主基因-多基因模型分离分析法对低磷土壤条件下玉米082×掖107组合的P1、P2、F₁、F₂和F_2∶3代磷吸收和利用效率联合遗传分析。结果表明,玉米磷吸收效率遗传符合一对加性-显性主基因与加性-显性-上位性多基因混合遗传模型(D-0)。F₂和F_2∶3估计的主基因遗传力分别为51.96%和56.29%,估计的微效多基因遗传力分别为34.17%和29.72%。主基因的遗传力都高于微效多基因,磷吸收效率的遗传主要由一对加性-显性主基因控制,同时微效多基因对玉米磷吸收效率的影响较大。表明可以利用磷吸收效率高的玉米亲本配制杂交组合,并且在育种的早期阶段选育磷吸收效率高的单株或家系,以获得磷吸收效率高的玉米品种。玉米磷利用效率遗传符合加性-显性-上位性多基因模型(C-0),属非主基因控制的遗传。表明玉米磷利用效率主要由微效多基因控制,可以结合玉米磷吸收效率性状的选育,培育磷利用效率高的玉米品种。     

小麦雄性不育系AL18A育性恢复基因的QTL定位

为加快AL型杂交小麦的发展,以不育系AL18A、恢复系99AR144-1及二者杂交F2代群体为材料,选用SSR标记和分离群体分组分析法进行育性恢复基因的QTL定位。结果表明,育性恢复由主效和微效基因共同控制,采用复合区间作图法分析,在1B染色体上检测到了1个主效恢复基因QTLqRf-1B-1,在5AL染色体上检测到了1个微效QTLqRf-5A-1。qRf-1B-1位于SSR标记Xbarc8与Xgwm413之间,与两标记的遗传距离分别为0.85cM和2.00cM,LOD值为14.06,加性效应为18.87,可解释22.43%的表型变异;qRf-5A-1位于SSR标记Xgwm595与Xgwm410之间,与两标记的遗传距离分别为10.00cM和0.10cM,LOD值为3.18,加性效应为12.32,可解释5.44%的表型变异。     

玉米分蘖率的遗传研究

以ph4cv(高分蘖率)×A6(低分蘖率)DH群体分蘖率为研究对象,应用主基因+多基因DH群体遗传模型及混合分布方法,研究玉米分蘖率的遗传特性,并对近缘群体、杂优群体和自交系群体分蘖率进行推导分析,利用六世代(ph6wc×ph4cv)分蘖率进行验证。结果表明,玉米分蘖率是由4对主基因和微效多基因共同决定的,主基因遗传力为95.6%,为加性-显性-上位性模型。主基因决定玉米分蘖率的稳定性,微效多基因是否表现及表现大小决定该群体的分蘖率。     

4个环境下稳定表达的控制粳稻穗角性状的新位点

 在4个环境下种植直立穗粳稻品种秀水79与弯曲穗品种C堡及两者杂交后衍生得到的RIL群体254个株系并调查其穗角,运用主基因+多基因混合遗传模型对穗角性状进行遗传分离分析;运用基于混合线性模型的QTLNetwork 2.0软件和基于多元回归模型的WinQTLcart 2.5软件的复合区间作图法,对穗角性状进行QTL定位。结果发现,1）穗角性状受两对主基因+多基因共同控制,以主基因遗传为主;2）QTLNetwork 2.0检测到8个控制穗角性状的加性QTL,解释表型变异的0.01%~39.89%;WinQTLcart 2.5检测到12个控制穗角性状的加性QTL,可解释表型变异的2.83%~30.60%。检测到的所有QTL分布于第4、5、6、7、9、11染色体上,其中分布于RM3700-RM3600和RM5652-RM410区间的两个主效位点qPA9.2和qPA9.5,以及分布于RM257-OSR28区间的qPA9.7 在两种方法和4个环境下均检测到,减效等位基因来自秀水79;3）检测到8对加性×加性上位性互作位点,解释表型变异的0.36%~1.71%。检测到的各个加性和上位性位点均不存在显著的基因型与环境的互作。      

小麦品种里勃留拉的持久抗条锈性遗传机制

为了探索小麦品种持久抗条锈病性的遗传机制,对持久抗条锈小麦品种里勃留拉进行了成株期抗病特点和抗性遗传分析,并对主效基因与微效温敏基因共同控制的持久抗病性的鉴定选择方法进行了探讨。结果表明,里勃留拉前期反应型为2～3型,后期转为1～2型,其典型特征表现为普遍率低、严重度低、病情指数低、病斑小、病斑扩展速度慢。遗传分析表明,里勃留拉抗性由1对显性和1对隐性共2对互补的主效基因和若干成株期微效温敏基因共同控制。在杂交转育时要扩大选择群体,在早代进行混合选择,晚代进行单株选择。在成株发病前期,以低普遍率和中抗为标准选择主效基因组合;在发病后期,应以反应型和严重度的降低为标准选择微效基因组合。研究还表明,里勃留拉的干尖性状是由具重复作用的2对隐性基因控制,与抗锈性之间存在相关,但作为抗条锈性辅助选择的形态标记其可靠性较低。     

玉米自交系齐319对玉米灰斑病的抗性遗传分析

利用齐319与10个不同抗病水平的玉米自交系组配的F_1及其与感病自交系丹340、龙抗11构建的F_2群体为试材,通过人工接种鉴定,研究自交系齐319对灰斑病的抗性遗传规律。结果表明,选用齐319作抗性亲本,由其组配杂交组合可明显降低灰斑病发病程度,除与高感材料组配外,均能使杂交组合抗病性达到中抗以上水平。利用单个分离世代分析,齐319与龙抗11组配的后代群体符合B-2模型,即两对加性-显性主基因遗传模型;与丹340组配后代群体符合B-1模型,即两对加性-显性-上位性主基因遗传模型。利用齐319组配群体,在不同遗传背景下,齐319均表现出2对主效抗性基因,在龙抗11背景下表现出的主基因遗传率更高,基因作用方式更简单。     

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.