稻瘟病抗性基因Pi1和Pi2的聚合及其育种价值分析

水稻稻瘟病的发病受外界条件影响较大,单纯依靠人工接种抗性鉴定比较困难。因此,人工接种抗性鉴定与分子标记辅助选择结合应用对提高抗性育种效率具有重要意义。本研究利用已建立的水稻抗稻瘟病基因Pi1和Pi2显性分子标记,对黑龙江省主栽品种空育131进行分子标记辅助选择,将Pi1和Pi2基因聚合到空育131中,对其原始亲本和不同基因组合聚合后代进行了稻瘟病田间抗性鉴定,对2个抗性基因的聚合效应进行了统计和评价,由此明确了Pi1和Pi2基因在寒地育种辅助选择中的应用价值。     

抗稻瘟病Pi2/9/z-t基因特异性分子标记的开发

通过对已克隆的抗稻瘟病基因Pi2、Pi9以及Piz-t进行序列比对,寻找各自特异的核苷酸差异,成功开发了基于PCR技术以及电泳检测技术的Pi2/Pi9/Piz-t以及Piz-t的基因特异性分子标记,能有效地将Pi2/Pi9/Piz-t与该位点上的其他抗性等位基因及感病等位基因区分开,这为分子标记辅助育种及抗病基因聚合提供有效的分子标记。用Pi2/Pi9/Pizt基因特异性分子标记对来自全国各稻区的共101份水稻品种和育种亲本进行分子检测,结果发现,除2个品种检测到Piz-t带型之外,大部分水稻品种不携带这3个抗性基因,这为有目的地开展品种的抗性改良提供了重要的参考信息。     

花生锈病抗性的AFLP标记

利用抗、感锈病的花生品种为亲本配制杂交组合远杂9102 ×ICGV86699,以其F2分离群体为研究材料, 利用BSA 法和AFLP技术,获得了与锈病抗性连锁的2个分子标记,与抗性基因间的遗传距离分别为10.90cM和7.86cM。利用获得的分子标记对其F3进行了验证，分子标记与抗性鉴定结果具有较高的一致性。     

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。     

大豆对胞囊线虫抗性遗传与分子标记研究进展

大豆胞囊线虫是一种世界性的病害.已经证明大豆对胞囊线虫的抗性受多个基因控制.但由于抗性鉴定工作量大、易受环境因素影响以及大豆胞囊线虫群体本身的异质性,各个研究者的结果差异很大,具有抗源和组合特异性.Riggs等建立的生理小种鉴定模式虽被广泛采用,但鉴别寄主中抗性基因的重叠引起研究者的争议.分子标记结合经典遗传试验定位了2个抗性基因位点rbg1和Rhg4,rhg1在抗性遗传中贡献较大且具有非小种专化抗性,对抗病育种和基因克隆有重要意义,在G连锁群上许多与rhg1紧密连锁的分子标记已经找到,并证明在抗性鉴定中有很大的利用价值.Rhg4位于A连锁群上,距离i位点0.35 cM,与1、3号小种抗性有关.     

湖北省66份小麦品种(系)赤霉病抗性鉴定与分子检测

赤霉病是由禾谷镰刀菌引起的小麦穗部病害,严重危害小麦生产,抗赤霉病品种选育是减轻其危害的重要途径之一。本研究以湖北省不同时期审定的59个小麦品种和选育的7份优异品系为材料,采用喷雾接种对其进行田间赤霉病抗性鉴定,并利用抗性基因Fhb1功能性分子标记和主效抗性基因(Fhb2、Fhb4、Fhb5和QFhs.crc-2DL)连锁分子标记对供试材料进行检测,分析其遗传分布和利用状况;同时分析湖北小麦品种(系)赤霉病抗性、株高和小穗密度等性状年代间的差异。结果表明,16份供试材料赤霉病抗性水平达到中抗,占比24.2%,以810619品系抗性最好,病情指数略低于苏麦3号;42份材料达到中感,占63.6%。分子检测结果显示,仅鄂T45048携带Fhb1;鄂麦11、鄂麦18和810619等29份材料(43.9%)可能携带Fhb5和QFhs.crc-2DL单个或2个抗性基因,说明这2个抗性基因在湖北小麦赤霉病抗性育种中得到了较多应用。赤霉病抗性与株高的相关性分析结果显示,近15年湖北小麦品种株高持续降低,但其与赤霉病抗性无显著相关。研究结果为明确湖北小麦品种赤霉病抗性水平和分子遗传基础提供了参考。     

SSR分子标记在稻瘟病抗性育种中的应用

稻瘟病俗称水稻癌症,每年都造成严重损失。实践证明,发展抗性育种是解决这一问题最有效的方法之一。SSR分子标记为辅助选育抗稻瘟病水稻新品种和抗性鉴定提供了新的方法和手段。阐述了SSR分子标记在水稻遗传连锁图谱构建、稻瘟病抗性基因定位、稻瘟病菌危害研究、分子标记辅助育种当中的应用,以为以后的研究奠定基础。     

水稻稻瘟病抗性基因研究进展

概述了稻瘟病抗性基因的经典遗传鉴定、分子标记定位、克隆以及稻瘟病抗性基因与无毒基因的互作等方面的研究进展。     

赤霉病主效抗性QTL区域SSCP标记的发掘与验证

为开发简便、高效的小麦抗赤霉病辅助育种的DNA标记,将一个基于ABI DNA序列分析仪、与3BS上赤霉病抗性主效QTL紧密连锁的分子标记转化为简便的SSCP (DNA 单链构象多态性标记,Single Strand Conformational Polymorphism marker) 标记并进行了验证。该SSCP标记可有效区分抗感品种之间的差异。对36个小麦品种进行了基因分型和赤霉病抗性鉴定,在5个已知有3BS抗性QTL的抗赤霉病品种和4个感病的品种中,抗性鉴定结果与标记的带型完全一致。在36个品种中,R带型表现为抗病的比率为100%;S带型表现为感病的比率为65.2%。表明该SSCP标记可应用于小麦抗赤霉病分子标记辅助育种。     

大豆抗花叶病毒SC3株系的分子标记筛选及种质抗性鉴定

为进一步寻找与大豆花叶病毒(Soybean Mosaic Virus,SMV)流行株系SC3抗病基因(Rsc3)紧密连锁的分子标记,以促进SMV抗病基因挖掘及抗病品种的选育,本研究利用96份品种(系)对SMV抗性位点Rsc3附近新设计的30个SSR标记和50个已知与Rsc3连锁的SSR标记进行初筛,然后采用基因型与表型和血清学鉴定相结合的方法,对288份2016-2019年中国新育成的大豆品种(系)进行了大豆花叶病毒SC3株系的抗性鉴定.结果表明:筛选到1个新开发的SSR标记CH0211,与大豆品种抗性表型选择的符合率为87.8％;进一步利用该标记对288份大豆品种(系)进行检测和分析,结合人工接种表型和血清学联合鉴定,抗病表型与基因型符合率为80.56％.288份大豆品种(系)中共鉴定出158份对SC3表现抗病的大豆品种(系),占参试材料总数的54.86％.鉴定出与抗病品种带型一致的材料144份,PI96983、齐黄34、汾豆104、山宁28等116份品种(系)的抗性表型与抗病分子带型一致.本研究开发和鉴定了1个与Rsc3紧密连锁的分子标记CH0211,该标记可有效用于大豆品种抗SMV SC3的种质资源筛选,加速大豆抗SMV育种进程.     

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).