水稻白叶枯病(Xanthomonas campestris pv．oryzae)抗性遗传研究:II．水稻品种对五个菌系的抗性遗传分析

 研究了5个水稻品种邳早l5、蚌珠芒、南粳l5、中百4号和青华矮6号对3个水稻白叶枯病菌系的抗性遗传和抗性基因等位关系。这5个品种分别与感病品种沈农lO33杂交，对各组合的F1、F2和B1F1群体的抗性测试表明：邳早l5和蚌珠芒由一对显性基因控制其抗性。南粳l5和中百4号均由两对连锁的显性基因控制，交换值为30％。等位性测定表明，邳早15和蚌珠芒的一对显性基因与Xa-3等位，南粳l5和中百4号也均有一对显性基因与Xa-3等位；青华矮6号的一对不完全显性基因与Xa-3是等位的。     

大豆对重组型SMV株系的抗性遗传

为探明大豆对大豆花叶病毒(SMV)重组型分离物(HB-RS)抗性遗传方式和不同抗性材料间抗性基因的等位性关系,利用抗病性鉴定获得的抗、感病大豆材料配制抗×感、抗×抗杂交组合,分析大豆携带抗性基因的遗传规律和等位性关系。研究结果显示5组抗感组合冀豆12×Franklin、冀豆17×10Y105、冀豆12×PI632401、PI96983×ZYD2738以及五星4号×FH13的F_1均表现为抗病,F_2植株符合3∶1或15∶1(抗∶感)分离比例;抗抗组合中,冀豆12与Newton和PI96983的F_1和F_2均表现抗病,冀豆12×V94-5152组合的F_1植株表现抗病,F_2呈现15∶1(抗∶感)的分离,冀豆17分别与Newton、PI96983及V94-5152组合的F_1均表现抗病,F_2出现15∶1(抗∶感)分离。分析表明,冀豆12、冀豆17和PI96983各由1对显性基因控制对重组型SMV(HB-RS)的抗性,五星4号的抗性由2对显性抗病基因控制;冀豆12携带的抗性基因与Newton和PI96983等位或紧密连锁,与V94-5152不等位,冀豆17携带的抗性基因与Newton、PI96983和V94-5152均不等位。     

水稻白叶枯病的抗性遗传研究

 以4个晚粳品种为材料，采用双亲本回交设计对白叶枯病抗性的遗传特性及基因效应作了分析。参试的晚粳品种对两个菌系KS-6-6和浙173的抗性是不完全隐性遗传，符合加性－显性模型；基因的加性效应为极显著，显性效应和上位性效应则皆不显著。加性变异和显性变异并存，但以加性遗传变异为主，表现具有较高的广义、狭义遗传率。菌系Ⅱ与Ⅳ的病级间的关联性表明，晚粳品种嘉23对白叶枯病两菌系的抗性属同一多基因系控制的不完全隐性的数量性状遗传；从有效因子数目估值来看，本研究参试材料至少有一对隐性抗病基因在起作用。     

三个粳稻品种的稻瘟和白叶枯病抗性遗传分析

 分析了城特232、嘉23和浙湖8号等3个粳稻品种对稻瘟病菌ZD1、ZE1和ZF1及白叶枯病菌8810-1的抗性遗传,结果表明,3个抗病亲本对ZD1、和ZF1的抗性都带有2对显性重复基因。等位性测定表明其中至少有1对是等位的，对ZE1小种的抗性均受1对显性基因控制，等位性分析三者的抗性基因各不相同。城特232和嘉23对白叶枯病抗性是由1对显性基因控制，而浙湖8号为2对显性互补基因控制。等位性测定表明城特232和嘉23的1对基因是等位的，但与浙湖8号的2对抗性基因是不等位的。推断了抗病亲本的可能的抗性基因。     

三个粳稻品种的稻瘟和白叶枯病抗性遗传分析

分析了城特232、嘉23和浙湖8号等3个粳稻品种对稻瘟病菌ZD_1、ZE_1和ZF_1及白叶枯病菌8810-1的抗性遗传。结果表明,3个抗病亲本对ZD_1和ZF_1的抗性都带有2对显性重复基因,等位性测定表明其中至少有1对是等位的。对ZE_1小种的抗性均受1对显性基因控制,等位性分析三者的抗性基因各不相同。城特232和嘉23对白叶枯病抗性是由1对显性基因控制,而浙湖8号为2对显性互补基因控制。等位性测定表明城特232和嘉23的1对基因是等位的,但与浙湖8号的2对抗性基因是不等位的。推断了抗病亲本的可能的抗性基因。     

水稻抗褐飞虱新基因

对某些水稻品种进行抗褐飞虱遗传研究,发现了以往尚未鉴定过的抗性基因。等位性测验表明,泰国品种‘Col 5’和‘Col 11’以及缅甸品种‘Chin‘Saba’的抗性是由一对和隐性基因控制,定名为bph8(t),斯里兰卡品种‘Balamawee’,Kaharamana’和‘Pokkali’的抗性是由一对显性基因控制,定名为Bph9(t)。     

四个云南水稻品种对白背飞虱的抗性遗传分析

 分析了鬼衣谷、便谷、大齐谷备和大花谷四个籼型云南地方品种的单显性抗白背飞虱基因与与Wbph3、Wbph5间，以及四个云南地方品种抗性基因间的等位性关系。结果表明，鬼衣谷等四个品种所携带的单显性抗虫基因均与Wbph3和Wbph5间为非等位关系；鬼衣谷、便谷、大齐谷和大花谷各所携带的单显性抗虫基因间互为等位关系。在鬼衣谷等四个云南地方品种中发现了一新的抗白背飞虱抗性基因，暂将这一新的抗性基因定名为Wbph6(t)。     

几个籼稻品种对稻瘟病抗性的遗传分析

用感稻瘟病品种二九青与4个抗病品种杂交的 F₁、F₂、B₁F₁经4个不同菌系的稻瘟病菌孢子悬浮液分别进行人工接种,然后考查其抗性反应。结果表明红脚占、砦糖、Tetep 和74-5461BG 等籼稻品种对 ZB1、ZB15、ZC15、ZC3菌系的抗性均分别由显性抗性基因 Ipi-1、Ipi-2、Ipi-3和 Ipi-4控制,同时这4个抗性基因还存在着紧密的连锁关系。等位性测定也表明4个品种所具有的抗性基因都是各各等位的。     

大豆对大豆花叶病毒SC18株系的抗性遗传和基因定位

大豆花叶病毒(soybean mosaic virus,SMV)病是我国大豆生产上的一种主要病毒病害,SMV株系SC18是我国东北和南方两大产区的优势株系,在黄淮大豆产区亦零星发生。本研究对5个抗×感杂交组合衍生后代分离群体接种SC18后,发现各组合F_1均抗病,F_2表现3∶1(抗∶感)分离比,F_(2∶3)表现1∶2∶1(抗∶分离∶感)的分离比,表明5个抗病亲本(中作00-683、滨豆95-20、东大2号、中品661和RN-9)对SC18的抗性由一对显性基因控制。抗×抗杂交组合"中作00-683×东大2号"衍生后代分离群体接种SC18,F_2出现15∶1(抗∶感)的分离比,表明中作00-683与东大2号可能各携带一对显性基因,控制对SC18的抗性,且独立遗传;抗×抗杂交组合"中作00-683×滨豆95-20"的F_1、F_2和F_(2∶3)在接种SC18后均未检测出感病株,表明中作00-683与滨豆95-20所携带的对SC18的抗性基因是等位的。利用RN-9×7605重组自交家系将RN-9对SC18的抗病基因Rsc18定位到大豆6号染色体(C2连锁群)SSR标记Satt286和Satt277之间,遗传距离为6.12和4.69 cM。     

水稻抗白叶枯病的新基因

1978年,在田间研究了水稻(OryzaSativa L.)58个抗白叶枯病Xanthomonas campestris pv Oryzae(Ishi yama1972Dye)品种的遗传方式和基因的等位关系。由抗病品种和感病品种“TNI”杂交组合F_1和F_2群体的分析揭示了48个品种的抗性变由单一显性基因控制,其余的10个品种的抗性变单一隐性基因操纵。等位基因测验表明这48个品种具有Xa4抗性基因,8个品种的隐性抗性基因与Xa5等位。然而,“Khao Lay Nhay”和“Sateny”品种的隐性抗性基因彼此是等位的,与Xa3、Xa4、Xa5、Xa7和Xa8不等位且可独立分离。这个新的隐性基因同Xa6连锁,其同型染色体局部交换值为5.9％。因而,品种“Khao Lay Nhay”和“Sateng”有新的抗性基因,这种基因定名为Xag。水稻白叶枯病(Xanthomonasc ampestris pv.oryzae)是亚洲分布最广的一种水稻病害。早在1930年代,日本就开始系统研究寄主植物对白叶枯病的抗性并鉴定出许多抗日本菌系的品种(Mizukami1966,Ezuka和Horino1974)。研究了对日本菌系的抗性遗传并鉴定出三个抗性位点(Nishimura和Sakaguchi 1959,Sakaguchi 1967和Ezuka等1975)。把这三个位点叫做Xa1、Xa2、Xa3。在热带地区,早在1960年代,国际水稻研究所(IRRI)开始系统研究水稻白叶枯病并鉴定了3000多个抗病品种。近10年间,在进行遗传研究的基础上,鉴定出抗菲律宾菌系的另外5个抗性基因(Xa4、Xa5、Xa6、Xa7和Xa8)(Petpisit等1977;Olufowote等1977;Sidhu和Khushl978;Siolhu等1978)。其中,Xa4和Xa5分布最广。这两个基因彼此独立分离。Xa6与Xa4连锁(Sidhu和Khush 1978)。在IRRI和其它地方Xa4、Xa5和Xa6被广泛地用于育种计划,为了鉴定另外的抗性基因,进行了本研究。     

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.     

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.