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。     

利用功能标记鉴定普通野生稻中的白叶枯病抗性基因

 以9个菲律宾白叶枯病菌小种对供试的9份普通野生稻（Oryza rufipogon Griff.）及1份高感白叶枯病材料IR24进行抗性鉴定,发现IR24对所有的菌株都表现为高感, 6份野生稻材料对9个菌株表现全抗,占参试野生稻总数的67%。取自广西玉林的1份材料只感PXO280(P8),海南万宁的1份材料感PXO71(P4),广州高州的1份材料对PXO79、PXO99和PXO339感病,而这几份材料对其余菌株都表现为抗病,说明每份材料至少含有1个抗性基因。利用已克隆的白叶枯病抗性基因xa5、xa13、Xa21和Xa27的功能标记检测,结果表明9份供试普通野生稻中都不含抗性基因xa5、Xa21;5份为显性Xa13纯合体,4份为隐性抗病xa13杂合体;5份为抗病显性Xa27纯合体,3份为隐性xa27纯合体,1份材料中xa27和Xa27都不存在。     

水稻白叶枯病抗性基因鉴定进展及其利用

 1982~1987年，日本热带农业研究中心（TARC）和国际水稻研究所（IRRI）合作采取统一研究方案，创建了国际水稻白叶枯病抗性鉴别系统。统一了命名，删去了重复（包括与Xa3相同的Xa4b、Xa6和xa9）。截至2005年6月，经国际注册确认和期刊报道的水稻白叶枯病抗性基因共30个，其中 Xa22(t)、Xa26(t)、xa26(t)、Xa27(t)、xa28(t)、Xa29(t)和3个Xa25(t)为暂定名基因，有待订正。在30个基因中，21个为显性基因（Xa），9个为隐性基因（xa）；13个表现全生育期抗性，15个为成株期抗性，Xa21和Xa25(t) (O. minuta)两个基因在分蘖后期表达抗性。已被定位的抗性基因有17个，即第11染色体上有7个，Xa3、Xa4、Xa10、Xa21、Xa22(t)、Xa23和Xa26；第4染色体上有4个，Xa1、Xa2、Xa12和Xa14;第5染色体上有2个，xa5和xa13；第6染色体上有Xa7和Xa27；第12染色上有Xa25(t)；第1染色体上有Xa29（t）。包括Xa1、xa5、Xa21、Xa26五个基因已被克隆。并讨论了合理利用抗性基因等问题。     

103个杂交稻亲本白叶枯病和稻瘟病抗性基因型检测

白叶枯病和稻瘟病是我国水稻生产的主要病害,选育抗病品种是一种经济有效的防治手段。明确抗性基因在水稻品种资源中的分布,将有助于应用分子标记辅助选择培育抗性品种。本研究针对13个重要抗病基因,包括8个白叶枯病抗性基因(Xa1、Xa4、xa5、Xa7、xa13、Xa21、Xa23和Xa26)和5个稻瘟病抗性基因(Pib、Pi2、Pi9、Pi25和Pita),应用这些基因的基因标记或连锁标记共29个,检测103份杂交稻亲本,初步确定了其等位基因分布和利用情况,为水稻基础材料的筛选及应用提供参考。     

疣粒野生稻抗白叶枯病新基因的初步鉴定

以10个菲律宾白叶枯病菌小种和1个中国白叶枯病菌小种为供试菌系,以高感白叶枯病水稻品种IR24及携有不同抗白叶枯病基因的近等基因系IRBB1等16个材料作为参照,对粳稻品种8411/疣粒野生稻体细胞杂交获得的两个抗白叶枯病新种质SH5和SH76进行了白叶枯病抗谱鉴定。结果表明SH5和SH76在苗期的抗谱较广,并且与已知抗病基因的抗谱不同,但与IRBB5(xa5)和IRBB7(Xa7)相似。分别用xa5和Xa7的分子标记2F_1R和M5进行检测,确定SH5和SH76中不含有xa5和Xa7基因。初步推测SH5、SH76可能含有一个新的抗病基因或者一个连锁的基因簇群。     

利用分子标记技术聚合2个白叶枯病基因改良华占的白叶枯病抗性

以镇084和IRBB5为白叶枯病抗性基因的供体亲本,华占为受体亲本,通过杂交、二次回交,再进行一次复交,在分离世代利用分子标记辅助选择技术、白叶枯病菌接种鉴定和农艺性状筛选等措施,育成携带xa5、Xa7和xa5+Xa7基因的改良株系各1个,并对改良株系进行了抗白叶枯病鉴定。结果表明,分别携带xa5、Xa7基因的改良株系B1和B2对菌株PXO99均表现为高感,对其他4个菌株都表现为高抗或抗;携带xa5+Xa7基因的株系B3对PXO99表现为中感,对其他4个菌株都表现为高抗,抗性水平明显好于仅携带单基因的B1和B2。     

多基因聚合育成优质高产杂交稻新组合中优161

通过文献检索和基因标记检测,判定水稻品种特青和抗白叶枯病基因聚合品系IRBB51所携带的有利基因,其中特青携带抗稻瘟病基因Pib和Pita、抗白叶枯病基因Xa4,IRBB51携带抗稻瘟病基因Pib、抗白叶枯病基因Xa4和xa13、优质基因wx。建立了特青/IRBB51重组自交系群体,育成在5个目标基因座位上均携带有利等位基因的恢复系中恢161,与不育系中9A配组育成优质、高产的杂交稻新组合中优161,于2009年通过国家农作物品种审定。研究表明,综合利用不同水稻材料携带的共有有利基因和互补有利基因,可快速有效地实现多性状有利基因的聚合。     

水稻品种Cas209抗白叶枯病遗传

研究了水稻品种Cas209对菲律宾稻白叶枯病菌群Ⅱ代表菌系Pvo86的抗性遗传方式。对Cas209与感病品种杂交的F_1、F_2、和回交群体的分析,揭示了Cas209抗性由单一的显性基因所控制。连锁关系试验表明,这一新鉴定的显性基因与Xa-4连锁,重组值为27.4％,但与xa-5是独立的。这个新的抗白叶枯病基因定为Xa-10。     

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。     

分子标记辅助选择与花药培养相结合快速聚合水稻白叶枯病抗性基因

以受微效多基因控制白叶枯病抗性的五丰占2号和主基因[i]xa5[/i]控制的IRBB5为材料,应用分子标记辅助选择、花药培养和回交技术研究了主基因与微效多基因聚合的途径。经查阅GeneBank中RG556的序列,利用在线引物设计软件Primer 3设计了一条新的R引物：5′CCAGACACCACTGCACATTC3′,克服了原引物Tm值相差太大,扩增效率低的缺点,使PCR扩增效率提高了近10倍。采用病斑长度与五丰占2号相近且携有xa5基因的五丰占2号[sup]2[/sup]/IRBB5 B[sub]1[/sub]F[sub]1[/sub]植株进行花药培养,获得30株二倍体植株,其中16株携有[i]xa5[/i]基因。携有[i]xa5[/i]基因的植株的平均病斑长度仅0.1 cm,对白叶枯病的抗性明显强于双亲。成功地聚合了白叶枯病抗性主基因和微效多基因。从配组到获得主基因和微效多基因聚合材料仅用两年时间,比常规育种方法缩短1~2年。     

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.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Marine Pharmacology in 2016–2017: 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 review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.     

Effects of Micronutrient Deficiencies on Human Health: Its Status in South Asia

SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.     

In vitro reproduction in the annual pasture legumes subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.)

Pasture legumes are important components of both mixed farming rotations and permanent pastures in temperate climates. Breeding of two widely sown pasture legumes, subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.), is constrained by the long generation cycle, typically enabling only one generation per year. We hypothesized manipulation of culture medium and conditions would enable the development of a laboratory‐based protocol for in vitro reproduction in subterranean clover and French serradella. In vitro flowering and viable seed set was induced from both species. For subterranean clover, the most effective treatment was culturing on modified MS medium with 1 μm kinetin and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and continuous photoperiod. For French serradella, culture on a hormone‐free B5 medium with 5 mm NH₄Cl and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and 20 h photoperiod was optimum. It is expected this technique will have application in accelerating generation turnover within breeding programs, for the study of factors influencing flowering in pasture legumes, and for the propagation of valuable yet enfeebled plants such as embryo‐rescued hybrids.     

Management of Soil Micronutrient Deficiencies in the Rice-Wheat Cropping System

Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.     

Irrigation but not N fertilization enhances seedhead density in plains rough fescue ( F estuca hallii)

Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.     

Marine Drugs Regulating Apoptosis Induced by Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.     

Estimation of lucerne yield stability for enabling effective cultivar selection under rainfed conditions

Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change.     

Biochemical and morphological characterization of potato clones differing in their resistance to late blight

Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.