耐密型玉米自交系选育技术探讨

结合我国玉米育种的实际情况,对耐密型玉米自交系选育技术：增大选择密度、选择农艺性状、早代选择大群体、增大选择压力、提高自交系的抗逆性、目测选择外观性状、田间测定配合力、耐密育种材料的改良与创新,和耐密型玉米自交系选育技术存在的问题进行了探讨。     

玉米选系窄基础材料组配规律的初步研究

选用11个典型的优良自交系，通过不完全双列杂交试验，采用一般配合力、特殊配合力效应值简易估算法，得出11个优良自交系穗部各性状的一般配合力的效应值和部分组合特殊配合力效应值。据此结果分析，提供了选育各种优良穗部性状自交系的基础材料组合，并得出有关各种穗部性状的较高配合力的组合类型，从而为选育自交系及组配杂交种服务。     

对选育优良玉米杂交种的浅见

选育高产优质多抗的玉米杂交种，首先要在选育自交系方面下功夫，其次要进行自交系配合力的测定，组配突破性杂交组合，杂交种多点鉴定，区域试验和生产试验，力求采用最先进，最科学的手段，最准确的试验和数据分析方法，尽快选育出优良杂交组合。１　自交系选育１．１　选育目标众所周知，当今世界各国都把高产、优质、多抗、坚秆和耐密植作为选育玉米杂交种的基本目标。随着我国玉米生产水平的提高和栽培技术向高肥高密方向的转变，今后的育种目标应该是加强坚秆直立株，中棵向上叶及中大均匀果穗的选育。玉米自交系的选育在重视产量的同…     

玉米自交系C8605-2选育与利用

C8605-2的成功选育是近年来我国自交系选育的一个重要突破。C8605-2含有纯正的北美种质血缘,综合了双亲优良性状。继承了铁7922株型紧凑、秆强和沈5003矮秆、大粒的特点。表现株高穗位适中,株型紧凑,抗倒性强,抗病、抗逆性突出。雌雄协调,结实良好,制种产量高,一般配合力高。以C8605-2为亲本培育的玉米杂交种,产量高,稳产性好,适应性广;抗倒性、抗病性强,推广面积大,品种生命周期长。C8605-2是目前国内培育玉米杂交种和自交系的骨干自交系,已成为国内十分宝贵的优异种质资源。     

黄早四在我国玉米育种和生产中的重要地位

优良自交系黄早四是我国玉米育种和种子生产中最重要的骨干材料之一，它具有配合力高、植株紧凑、综合农艺性状好的突出特点，因而被广泛应用。近二十年来，由黄早四组配的杂交种，经省市以上审定推广的就有42个，黄早四杂交种累计推广面积达6亿亩以上，每年种植面积在5千万亩以上，为我国玉米育种和生产作出了巨大的贡献。由它组配的玉米杂交种株型紧凑或半紧凑，我国紧凑型玉米杂交种的选育和高产栽培研究得到了很大的发展。黄早四还是我国重要的种质材料，一大批黄早四衍生系及其杂交种育成。本文还讨论了优良地方种质的重新筛选改良，杂种优势模式和建立自交系发放制度等问题。     

不同密度下欧洲玉米种质BRC选系的应用潜力分析

以5个优良的欧洲玉米种质BRC自交系为母本、5个不同来源的优良自交系为父本,采用NCⅡ设计,组配25个杂交组合,在3种密度下对欧洲玉米种质BRC选系的杂种优势表现和配合力进行研究。结果表明,不同密度下,F_1代单株产量杂种优势普遍存在,变化趋势是随密度增加而降低。自交系BRC-1在60 000株/hm~2密度下有较高的GCA效应;自交系BRC-5在3个密度条件下均有较高的GCA效应,且随着密度的增加,GCA效应增加。同一组合在不同密度下SCA效应存在较大差异,SCA效应增减与密度增减的变化方向不一致。在3种密度下,总配合力较高的组合分别为BRC-5×D37、BRC-5×S121和BRC-5×HG162,在不同密度下单株产量的总配合力效应与杂种优势极显著正相关。综合分析认为,自交系BRC-5和BRC-1在实际育种中有较大的利用价值,用自交系BRC-5容易组配出高产耐密组合。欧洲种质×塘四平头和欧洲种质×旅大红骨+塘四平头的杂优模式在高产耐密杂交种选育中有很大的应用潜力。     

铁7922在玉米育种及生产上的应用

玉米自交系铁7922株型紧凑,茎秆坚韧,品质优良,配合力高,抗逆性强,遗传性状稳定,适应范围广,是优异的玉米自交系和种质资源。它的育成拓宽了我国玉米种质基因库,推动了我国玉米育种和生产的发展。自育成后直接利用其组配的杂交种通过国家和省级审定的有30余个;直接或间接利用其选育自交系达30余个,组配的杂交种通过国家和省级审定有50余个。     

吉林省耐密型玉米育种现状及选育途径初探

简要地分析了吉林省主要推广的耐密型玉米杂交种的组配模式和种质的利用情况,并对耐密型杂交种的特征、组配原则及亲本自交系的选育进行了系统的阐述。     

玉米品种兴达1号的选育与栽培要点

玉米育种是以利用杂种优势为主,从具有优良农艺性状、一般配合力和特殊配合力高的自交系为原材料进行选育。就玉米杂交种而言,一般5～7年更换1次。近几年甘肃省玉米育种工作者通过育种攻关,选育出了几个适应不同生态区种植的品种,但适用范围小,推广面积上不去,跟不上全省玉米生产发展的需要。     

紧凑耐密型玉米杂交种选育途径探讨

对紧凑型耐密型玉米自交系的种质类群以及紧凑耐密型玉米杂交种的杂种优势模式进行了分析,结果认为应当加强抗病类群的利用。运用Ｓ１密植改衣法以小区籽粒产量为主要选择性状对空秆率和抗倒选择效果较好。玉米杂交种的耐密性选择可以叶向值、抗倒性和空秆率作为主要选择性状。     

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.     

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.     

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.     

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.

     

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.