小麦抗白粉病基因定位及分子标记研究进展

本文是一篇有关小麦抗白粉病研究的综述,对已报道的所有３３个小麦抗白粉病基因的染色体定位及将ＲＦＬＰ和ＲＡＰＤ分子标记技术应用于小麦抗白粉病研究的最新进展进行了概括总结;还对小麦抗白粉病育种中存在的可利用抗病基因资源贫乏和抗源单一化问题及小麦抗白粉病基因分子标记研究中尚待解决的问题进行了探讨。     

小麦抗白粉病基因及其分子标记研究进展

小麦白粉病是小麦生产的主要病害之一、应用抗病品种是防治该病的十分经济、有效的措施。近年来分子标记技术的发展为小麦抗白粉病基因的研究提供了极大的方便。目前为止,小麦基因组中已定名抗白粉病基因31个．其中对20个基因位点的25个抗白粉病基因进行了标记和作图。本文对小麦抗白粉病基因染色体定位、来源、评价利用及其分子标记研究现状进行了综述,并对分子标记在小麦抗病遗传育种中的应用进行了探讨。     

小麦抗白粉病基因定位及分子标记研究进展

本文是一篇有关小麦抗白粉病研究的综述,对已报道的所有３３个小麦抗白粉病基因的染色体定位及将ＲＦＬＰ和ＲＡＰＤ分子标记技术应用于小麦白粉病研究的最新进展进行了概括总结,还对小麦抗白粉病育种中存在的可利用抗病基因资源贫乏和抗源单一化问题及小麦抗白粉病基因分示记研究中尚待解决的问题进行了探讨。     

基于近等基因导入系发掘玉米抗甘蔗花叶病毒主效基因

利用玉米自交系掖478与中自01构建近等基因导入系群体(BC4F2),通过田间人工接种甘蔗花叶病毒鉴定获得抗病植株。采用38个SSR标记分析抗病株基因型,通过连锁不平衡分析,在玉米第3和6染色体上发掘3个主效抗病QTL。第3染色体上的QTL置信区间为26.1cM-phi053-5cM;第6染色体上的QTL置信区间分别为1.2cM-bnlg161和5.3cM-bnlg1538-7cM。建立了基于近等基因导入系发掘玉米抗甘蔗花叶病毒主效QTL技术,获得了一批含有抗病毒QTL的近等基因导入系,为抗病育种提供了信息和材料。     

小麦品种Grandin抗白粉病基因的鉴定和SSR标记

为了明确美国红粒硬质春小麦品种Grandin在小麦育种中的利用价值,对其进行了白粉病抗性基因的鉴定,并利用分子标记进行了定位.遗传分析结果表明,Grandin携带1个显性抗白粉病基因,该白粉病抗性基因与小麦SSR标记位点Xcfd81和Xcfd78连锁,遗传距离分别为0.9 cM和3.3 cM.根据小麦微卫星标记遗传连锁图以及利用中国春第5同源群双端体系对这两个SSR标记位点的定位结果,该抗白粉病基因被定位于小麦染色体5D短臂,与小麦已知抗白粉病基因Pm2的定位结果基本一致.进一步通过标记多态性比较和小麦白粉菌分小种鉴定证实Grandin所含的抗白粉病基因就是Pm2.同时还对Pm2基因的STS标记在不同群体中的实用性进行了讨论.     

小麦品种(系)的白粉病抗性鉴定及分子标记的实用性评价

为评价抗白粉病基因分子标记在标记辅助育种中的实用性,以含已知抗白粉病基因的材料为对照,对来源于我国11个小麦主产省份的145个小麦品种(系)进行了苗期白粉病抗性鉴定,并检测了9个小麦抗白粉病基因的分子标记Xcfd81-5D(Pm2)、Pm4a/b(Pm4)、Xwg996(Pm6)、LAG95(Pm8Pm17)、CAU196(Pm12)、UTV14(Pm13)、Xgwm159-5B(Pm16)、Pm21D/E(Pm21)和Xgwm337(Pm24)在上述材料中的扩增情况。结果表明,在供试材料中,Pm8基因的分布频率达52.4%,但该基因已丧失抗性;Pm2、Pm4、Pm6、Pm12、Pm13、Pm16、Pm17、Pm21和Pm24基因抗性好,但在供试材料中的分布频率仅介于0~9.7%。抗性达高抗以上水平的品种含有的抗病基因主要为Pm2、Pm21和Pm24;有些抗病品种的遗传基础尚不清楚。根据抗性和分子鉴定的一致性差异可将供试小麦品种(系)分为4种类型:(Ⅰ)分子标记检测和表型鉴定均为阳性;(Ⅱ)表型鉴定呈阳性,但分子标记检测为阴性;(Ⅲ)分子标记检测呈阳性,但表型鉴定为阴性;(Ⅳ)分子标记检测和抗性鉴定均为阴性。分子标记可用于Ⅰ、Ⅱ、Ⅳ型材料中目标基因的选择,而无法用于Ⅲ型材料。表型和分子标记检测符合度高的分子标记UTV14(Pm13)、Pm21D/E(Pm21)实用性好。上述结果为开展抗白粉病分子育种提供了重要的参考。     

普通小麦“宁7840×Clark”RIL群体抗条锈病QTL分析(英文)

为了解小麦条锈病抗病基因在染色体上的位置,对源自小麦杂交组合宁7840×Clark的重组自交系(RIL)群体进行了抗条锈病QTL分析。结果表明,在染色体1BS上检测到一个主效的QTL即QYr-hwwg-1B。该QTL由抗病亲本宁7840提供,位于SNP标记Xsnp3620和Xsnp5435之间,区间长度为2.5cM,可解释55.8%的表型变异。根据宁7840的小种抗性推测QYr-hwwg-1B可能是由来自1B/1R易位系的抗病基因Yr9引起的。抗性基因Yr9、Yr10、Yr15、Yr24、Yr26、YrH52和YrAlp均位于小麦1B染色体短臂的一端,形成一个抗条锈基因簇,并与SSR标记Xgwm11紧密连锁。另外,有56个SNP标记与该标记区间共分离,可以用于小麦抗条锈基因精细定位图谱的构建及分子标记辅助选择育种。     

小麦抗白粉病基因 Pm4的分子标记辅助育种研究

Pm4是我国目前有效的小麦抗白粉病基因之一,该基因对陕西关中当前流行的白粉病菌系关中4号表现高抗。本研究利用与Pm4基因紧密连锁的STS470分子标记对7个小麦品种间的6个杂交组合F3代单株进行分子标记检测并结合田间抗性鉴定筛选出抗病单株14个。对由这14个单株衍生出的64个F5代品系进行分子检测和田间抗性鉴定,发现53个品系表现抗病,占总品系的82.81%,其中51个抗病品系可以检测到与Pm4基因紧密连锁的STS470特异带,占总品系的79.69%。本研究结果表明,STS470是Pm4基因的可靠标记,可有效的用于分子标记辅助育种。     

大麦抗白粉病研究进展

综述了大麦白粉病病原菌(Blumeria graminisf.sp.Hordei L.)致病型鉴定及大麦抗白粉病基因的鉴定、定位与克隆的研究。同时探讨了我国大麦抗白粉病育种的研究策略。     

利用微卫星标记定位一个新的小麦抗白粉病基因

小麦农家品种ZB90是一个广谱抗白粉病材料.苗期和成株期鉴定表明,其白粉病抗性由显性单基因控制.从位于不同染色体上的53对微卫星引物中筛选出3对引物(Wms382、Wms311和Wms312),对144株F2分离群体进行抗病连锁性分析.另外,与Pm4a共分离的STS标记STS-470也被用于基因定位.这4个标记和抗病基因在染色体上的顺序为:基因位点-Xgwm382-Xgwm311-STS-470-Xgwm312,它们之间的遗传距离分别为2.9、4.5、23.1和49.6 cM,与小麦染色体2AL上已构建的微卫星图谱顺序一致.根据材料来源和抗病基因的染色体定位结果,确定该基因为一个新的小麦抗白粉病基因,并命名为PmZB90.文中还讨论了PmZB90和其他位于染色体2AL上的基因之间的关系.     

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.     

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.     

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).     

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).     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.