Optimizing interfacial features to regulate neural progenitor cells using polyelectrolyte multilayers and brain derived neurotrophic factor

The development of biomaterials with controllable interfacial features which have the capability to instruct cellular behavior are required to produce functional scaffolds for the treatment of spinal cord injury (SCI). Here, poly-?-caprolactone surfaces were biofunctionalized via layer-by-layer (LbL) deposition. The polyelectrolytes employed in this LbL technique were heparin and poly-L-lysine (PLL), the latter being chosen to improve cell adhesion and the subsequent cellular function of in vitrocultured neural progenitor cells. Material characterization results confirmed the deposition of well structured multilayers. Cell culture studies revealed significant differences in the cellular response to these adhesive/nonadhesive (PLL/heparin) polyelectrolyte multilayer (PEM)surfaces, with neurite outgrowth being significantly promoted on the PLL terminating layers. In addition, brain derived neurotrophic factor (BDNF) was adsorbed onto the LbL surfaces. This combined chemical and biological effect was then characterized in terms of neurite length along with the full length/truncated isoform 1 tyrosine kinase receptor (TrkB-FL/TrkB-T1) and growth associated protein-43 mRNA levels. Here, the authors report the differential effect of adsorbed and soluble BDNF of different concentrations. Adsorbed BDNF promoted neurite outgrowth and led to elevated, sustained TrkB mRNA levels. These findings highlight the potential of PEM biofunctionalized surfaces with integrated chemical and neurotrophin supportive cues to overcome SCI inhibitory environments and to promote regeneration.     

Non-wound-induced suberization of tuber parenchyma cells: A physiological response to the wilt disease pathogenVerticillium dahliae

Verticillium spp. wilt pathogens enter the root and eventually penetrate xylem vessels of the plant where they can spread into the vascular tissue of the potato tuber. Infected tuber vessel elements often become discolored creating a serious internal tuber quality defect that prevents sale of raw product to its primary market. Despite the costly losses and disease issues created by these infections, the physiological responses to colonization of tuber vessel elements are poorly described, and a model system to study these responses in the laboratory has not been developed. The objectives of this research were to develop such a model system by determining if tuber vessel elements could be infiltrated withVerticillium spp. in a laboratory setting and if a detectable physiological response could be elicited and identified. Results demonstrated that tuber vessel elements in the model system could be infiltrated and that infiltration ofVerticillium dahliae Kleb. conidia into these vessel elements induced a suberization response on the walls of neighboring parenchyma cells. However, the walls of the infiltrated tuber vessel elements did not suberize. A similar suberization response was found in tubers that had been naturally infected byVerticillium dahliae in the field. The suberization response was histochemically determined by assessing the accumulation of suberin poly(aliphatics) and poly(phenolics). This process of internal suberization of tuber parenchyma cells occurred without induction by a wound signal. Consequently, the suberization signal was derived by introduction of the plant-pathogen into the tuber vessel elements. This simple model system provides a versatile tool to investigate the physiological responses of potato tuber to colonization of vessel elements. This is believed to be the first report for such a physiological response toVerticillium spp. in potato tuber.     

Assessment and analyses for the interpretation of potato late blight response in field studies

Potato seedlings and cultivars were successfully subjected to moderate to heavy late blight pressure in field plots to which a race complex of the pathogen was applied. Multiple assessments through the course of the epidemics revealed differences in overall disease susceptibility or resistance. Differences were also demonstrated in disease response patterns among potato lines with similar overall disease ratings. Use of principal component and cluster analyses established discrete groupings of potato lines. This provides a basis for a more objective interpretation of the results in identifying both overall disease response and pattern (slow or fast) of response of potato cultivars and breeding lines.     

花期延缓剂在杂交水稻制种上的应用

在水稻幼穗分化期使用花期延缓剂，可以推迟水稻三系不育系新香A的抽穗高峰期，使抽穗历期延长，对株高有一定影响，对其它经济性状无不良作用。     

云南野生稻对稻瘟病的抗性评价

 以Tetep、B40为抗、感对照品种,在湖南省烟溪病区病圃,采用自然诱发,鉴定云南普通野生稻(Oryza rufipogon Griff.)、疣粒野生稻(Oryza meyeriana Baill.)、药用野生稻(Oryza officinalis Wall.)以及小粒野生稻对稻瘟病的抗性。结果表明:药用野生稻发病最早,叶瘟病级严重度达到7级,病斑孢子层级达5级;云南普通野生稻中,景洪普通野生稻病级严重度达7级,病斑孢子层级5级,元江普通野生稻病级严重度达8级,病斑孢子层级7级;疣粒野生稻发病最迟, 病级发展缓慢,病级严重度为3级,病斑孢子层级1级。同田的小粒野生稻高抗稻瘟病。三种云南野生稻对稻瘟病的抗性评价为普通野生稻高感,药用野生稻感,而疣粒野生稻为中抗。     

玉米抗倒伏性评价方法的研究

选定抗倒性不同的10个玉米品种,对现有玉米抗倒伏研究方法进行比较研究,探索玉米抗倒伏综合评价方法。相关分析结果表明,倒伏系数是株高、单茎鲜重、茎秆机械强度和根量的综合体现,倒伏系数与倒伏程度的相关性达到极显著水平。通径分析表明,茎秆机械强度和根量对玉米倒伏系数有较大负作用,单茎鲜重和株高对倒伏系数的直接和间接的效应都较小。聚类分析将10个品种划分为5个倒伏级别。以倒伏系数为评价标准,能客观准确地反映10个玉米品种的抗倒性,抗倒性强的品种倒伏系数较小,依据倒伏系数可以建立玉米抗倒等级划分标准。     

Seed germination response of cuphea to temperature

Cuphea (Cuphea viscosissima Jacq. × C. lanceolata W.T. Aiton; PSR23) is a potential new oilseed crop. Its oil is high in medium-chain fatty acids that are suitable for detergent/cleaner applications and also for cosmetics. The objective of this study was to determine the critical temperatures for cuphea seed germination. To determine the base, maximum, and optimum temperatures for seed germination, mature cuphea seeds were harvested from plants grown at Prosper, ND, in 2004, 2005, and 2006. Seeds were germinated on a temperature-gradient bar varying between 5 and 35 °C. Cumulative germination was calculated for each temperature treatment. Base temperature (T_b) and optimum temperature (T_o) were estimated from the third-order polynomial temperature-response functions for each year. In addition, germination rate per day was used in a linear model to estimate the base temperature below which germination rate was equal to zero (T_b), and the maximum temperature above which germination was equal to zero (T_m). The optimum temperature (T_o) was calculated as the intercept of sub-optimal and supra-optimal temperature-response functions. Through the third-order polynomial temperature-response functions and the sub-optimal/super-optimal intercept approaches, we were able to generate six estimates for each critical value. Estimates of the base temperature for cuphea seed germination ranged between 3.3 and 11 °C, with the most reliable estimates between 6 and 10 °C, similar to many warm-season crops such as corn (Zea mays L.) and sorghum (Sorghum bicolor L.). The optimum temperature for cuphea seed germination ranged between 18.5 and 24 °C with a mean value of 21 °C. The maximum temperature for seed germination ranged 33–38 °C. On this basis, a cuphea planting date after 20 May is recommended for east-central North Dakota.     

10份香蕉种质对枯萎病的抗性评价(简报)

采用苗期、田间抗性评价方法,对引进的10份香蕉种质(台蕉1号、台蕉3号、台蕉4号、台蕉7号、GCTCV-106、GCTCV-119、GCTCV-247、FHIA-03、FHIA-18、FHIA-25)进行枯萎病4号小种的抗性评价.结果表明:10份香蕉种质中,GCTCV-119、FHIA-18、FHIA-25抗性为高抗;台蕉1号、台蕉4号、GCTCV-247、FHIA-03抗性为抗:台蕉3号、台蕉7号、GCTCV-106抗性为中抗.     

Assessment of hygienic quality of haylage fed to healthy horses

Wrapped forages such as haylage and silage are increasing in popularity in equine feed rations, but knowledge of their microbial composition, especially of haylage, is scarce. Haylage may be more at risk of mould growth compared to silage, and methods for the assessment of hygienic quality of haylage are needed. Varying culturing conditions, including aerobic/anaerobic incubation, four substrates and three incubation temperatures were therefore evaluated for analysis of fungi in haylage samples from eighteen horse farms, taken on two occasions (autumn and the following spring). Average mould counts in forage samples were low, but fungi with the potential for producing mycotoxins, such as Aspergillus fumigatus and Penicillium spp., were present. The microbial composition and content of fermentation products were similar in haylage samples taken in autumn and in spring. The type of substrate used for cultivation did not influence mould or yeast counts, but not all mould species were present on all substrates. Incubation temperature influenced fungal counts and the presence of mould species. By using at least two substrates (malt extract agar and dichloran 18% glycerol agar) and two incubation temperatures (25 and 37°C), all mould species/genera that were identified in this study could be detected.     

Assessment of the resistance of potato varieties to common scab

Summary Field and glasshouse methods of assessing the resistance of potato varieties to common scab were investigated and procedures which were found to give satisfactory results are described in detail. Estimates of resistance for individual varieties in the two environments were closely correlated. Examination of a number of isolates ofStreptomyces scabies showed that these varied greatly in virulence but no evidence of physiological specialisation was found.

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Zusammenfassung Feld- und Gew?chshausmethoden zur Feststellung der Resistenz von Kartoffelsorten gegen Schorf wurden untersucht. Verfahren, die zufriedenstellende Resultate ergaben, sind in Einzelheiten beschrieben. Die Sch?tzungen der Resistenz bei den einzelnen Sorten in den beiden Umgebungen standen in enger Wechselbezichung zu einander. Die Prüfung einer Anzahl Absonderungen vonStreptomyces scabies ergab, dass diese in Virulenz stark variierten; aber es wurde kein Fall von physiologischer Spezialisierung gefunden.

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Résumé Des méthodes d'évaluation de la résistance à la gale commune de variétés de pommes de terre ont fait l'objet d'investigations en plein champ et en serre, alors que les modes opératoires donnant des résultats satisfaisants, ont été décrits en détail. Une corrélation étroite a été établie entre les estimations de la résistance pour chacune des variétés distinctes, placées dans les deux ambiances. L'examen de quelques cas isolés deStreptomyces scabies a démontré une grande variation dans la virulence sans qu'une preuve de spécialisation physiologique ne fút fournie.

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Received for publication Jan. 9, 1958.     

Plant quality response to uptake of polluting elements

Several mineral elements which are found in excessive amounts in the environment, due to local pollution, influence plant growth and quality. The authors have studied the uptake pattern of some of these elements and their possible accumulation in plants. The contents in plants corresponding with phytotoxicity are experimentally determined. Different cases of harmfull effects towards animals and the problem of criteria for mineral element contamination are discussed, especially with regard to heavy metals and fluorine.In the second part the influence of mineral elements upon some organic plant constituents is studied. Analytical techniques such as electrophoresis, gel filtration and T.L. chromatography are used for separating some typical quality indicators such as chlorophyl, xantophyll, -cartotene and protein.Since Zn is typically an element giving very large content variations in plant tissues, its influence on the mentioned organic quality indicators is described in comparison with the effect of Cu, which is much less variable in the plants.

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Zusammenfassung Verschiedene Mineralelemente, die infolge Lokalpollution in überhohen Gehalten in der Umwelt gefunden werden, beeinflussen den Pflanzenwuchs und die Qualität.Die Autoren haben die Aufnahme von einigen dieser Elemente studiert und ihre mögliche Akkumulation in Pflanzen.Die Gehalte in Pflanzen, übereinstimmend mit ihrer Phytotoxizität, werden experimentell bestimmt. Mehrere Fälle von schädlichen Effekten auf Tiere und das Problem der Kriterien von einer mineralischen Elementenkontamination werden diskutiert mit Rücksicht auf Schwermetalle und Fluoride.Im zweiten Teil wird der Einfluß auf mehrere organische Pflanzenbestandteile besprochen. Die Analysenverfahren, Elektrophorese, Gel-Filtration und Dünnschicht-chromatographie wurden verwendet für die Trennung mehrerer typischer Qualitätsindikatoren, wie Chlorophyl, Xantophyll, -Carotin und Proteine.Der Einfluß von Zink, dessen Variabilität im Pflanzengewebe auf die genannten organischen Qualitätsindikatoren groß ist, wurde beschrieben im vergleich mit dem Effekt von Kupfer, das in der Pflanze weniger variable ist.

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Paper, read on the 8^th International mutual Congress of Quality Research of the CIQ with the German Society for Quality Research (DGQ) in Wädenswil/Switzerland from 7^th to 10^th Oct. 1975.

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Research program subsidized by IRSIA (Institut pour l'Encouragement de la Recherche Scientifique dans l'Industrie et l'Agriculture, Bruxclles).     

Varietal response of potatoes to air conditioning irrigation

A study of air conditioning irrigation on 4 varieties of potatoes was conducted over a 3-year period. Low volume irrigation during midday when the temperature was high was compared with the usual practice of applying 1″ of water at 3 to 4 day intervals when rainfall was inadequate. Air conditioning markedly increased yield in 1966 and 1968 when temperatures averaged near to above normal. This is in contrast to very little response in 1967 when the temperature averaged below normal. Varieties responded differently to air conditioning. Kennebec had the greatest increase in yield, and it also gave the most consistent increase during the 3-year period. The response of Viking, Norgold, and Norland was less consistent. Tubers in the air conditioning treatments had higher total solids than those under usual irrigation. Air conditioning had no visible effect on the incidence of the common foliar disease.     

Differential response of cold stored potato tubers to ethylene

The chip color of two potato varieties (Monona and Kennebec) processed directly out of 40 F storage changed in different directions after short exposure to ethylene and continued cold storage. Monona tubers produced much darker chips after ethylene treatment whereas non-enzymatic browning of Kennebec chips was considerably less after gassing. The distribution of pigmentation in chips prepared from both tubers was more uniform after ethylene treatment.     

3种类型油菜对干旱胁迫的生理响应

为了解芸薹属亚种间抗旱差异,选育抗旱材料,以3种类型油菜（甘蓝型油菜Q2、芥菜型油菜新油9号、白菜型油菜L14）为实验材料,采用盆栽控水法,测定干旱胁迫下油菜叶片光合参数、叶绿素荧光参数、水分等生理生化指标,研究3种类型油菜对干旱胁迫的生理响应和抗旱机制。结果表明：随着干旱胁迫的加重,三个不同油菜品种抗旱指标存在差异,其叶片的总生物量、离体叶片失水速率（RWL）、叶片相对含水量(RWC),叶绿素荧光参数及气体交换参数呈降低趋势,其中新油9号的光合系统受到的影响最小,Q2的光合系统受损最严重;根冠比、丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化物酶（POD）呈升高趋势,其中L14的SOD、POD活性在所有植物中升幅最大,干旱下分别为胁迫前的2.92、4.14倍。此外,3种类型油菜各有机溶质的积累量存在较大的差异,Q2和新油9号积累最多的是脯氨酸（Pro）,分别增至原来的12.37、6.60倍,L14则积累较多的可溶性蛋白（SP）,增至原来的6.55倍。隶属函数法分析得出抗旱性强弱顺序为：芥菜型油菜新油9号>白菜型油菜L14>甘蓝型油菜Q2。综上表明：油菜可以通过生长调节、光合抑制调节、活性氧代谢调节和渗透调节4种途径共同作用来响应干旱胁迫。     

A response of grey mould of potatoes to fertilizer treatment

Summary A fertilizer experiment on potatoes in which mechanical damage was followed by infection with grey mould (Botrytis cinera Pers. ex Fr.) provided the opportunity to make some observations on the incidence of the disease upon plants having different levels of mineral nutrition. It is suggested that the application of potash increases the resistance to infection by decreasing the host susceptibility to damage. The response to nitrogen may be governed by the pathogen's requirement for both nitrogen and carbohydrate.     

Assessment of pathogenicity ofRhizoctonia solani Kühn to some potato tissues and to cereals

Summary Isolates ofRhizoctonia solani Kühn were tested for their pathogenicity to potato sprouts growing from seed tubers. Those originating from sclerotia on tubers showed a wide range of pathogenicity but those from sprout tissue were only moderately pathogenic. Similar results were not obtained with detached potato sprouts, leaflets, or stem tips. Isolates from sclerotia which were very pathogenic to tubers, also caused considerable damage to sprouts, but isolates from potato caused little damage to wheat and barley seedlings compared to that caused by wheat isolates.

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Zusammenfassung Kartoffelkeime wurden im Boden mit Isolaten vonR. solani von zwei verschiedenen Herkünften infiziert, wobei versucht wurde, die Ergebnisse mit einfacheren Techniken zu erzielen, indem abgetrennte Keime, Bl?tter und Stengelteile verwendet wurden. Es wurden auch Versuche an Keimpflanzen von Weizen und Gerste vorgenommen, die beide fürR. solani anf?llig sind und in Grossbritanien gew?hnlich in Fruchtfolge mit Kartoffeln stehen. Zwei Isolate vonR. solani wurden aus L?sionen an Kartoffelkeimen und zwei von Weizenstengeln gewonnen. Die übrigen stammten von Sklerotien auf Knollen vom Lager von vielen Sorten, die auf einem weiten Skalenbereich von Bodentypen in Schottland angebaut wurden. Auf Agar gezogene Testisolate wurden direkt verwendet, um Getreides?mlinge am Halmgrund und um Platten mit Leitungswasseragar (TWA) oder Kartoffeldextrosebrühe zu inokulieren. Zerstückeltes Myzel aus Brühekulturen wurde zur Infektion des Pflanzenn?hrmediums benützt. Weizen- und Gerstens?mlinge wurden drei Wochen nach der Inokulation untersucht. Die losgel?sten Gewebe wurden auf drei Tage alte Kulturen der Testisolate auf TWA gelegt. nach sieben Tagen wurde die Virulenz von jedem Isolat, ausgedrückt als Funktion der Menge des verf?rbten Pflanzengewebes, gemessen. Die Kartoffelknollen wurden an Pflanzen, die in einem Glashaus w?hrend fünf Monaten in befallenem Boden angezogen wurden, untersucht. Wenn Isolate vonR. solani an Keimen an Pflanzkartoffeln getestet wurden, waren jene, die von Keimen stammten (Nr. 4 und 8), von m?ssiger Pathogenit?t, w?hrend jene von Sklerotien auf Kartoffelknollen eine umfangreiche Pathogenit?t aufwiesen (Tab. 1). Lose Keimteile reagierten nicht gleich wie an den Knollen angewachsene (Tab. 2), w?hrend Bl?tter (Tab. 3) und Stengelteile nur zu gewissen Zeiten der Vegetationsperiode vergleichbare Ergebnisse brachten. Kartoffelknollen waren insofern zufriedenstellend, dass ein Isolat virulent und an Keimen vergleichsweise stark pathogen war (Tab. 4 und 5). Die Ergebnisse von Versuchen an Weizen und Gerste lassen vermuten, dass kein starkes Auftreten von scharfen Augenflecken an diesen beiden Getreidearten zu erwarten ist, wenn sie nach einem ernsthaft vonR. solani (Tab. 6) befallenen Kartoffelbestand angebaut werden. (Die Werte in allen Tabellen, die eine gemeinsame Linie haben, weichen bei Anwendung des Duncan Multiple Range Test nicht signifikant (P 0,05) voneinander ab.)

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Résumé Des germes de pommes de terre ont été infectés dans le sol par des souches deR. solani provenant de deux lots de pommes de terre et des essais ont été réalisés pour relier les résultats à ceux obtenus avec des techniques plus simples utilisant des germes seuls, des folioles et des portions de tiges. Des essais ont également été effectués sur semences de blé et d'orge toutes deux sensibles àR. solani et entrant fréquemment dans les rotations avec les pommes de terre en Grande Bretagne. Deux souches deR. solani ont été obtenues à partir de lésions sur germes de pomme de terre et deux à partir de tiges de blé. Le reste provenait de sclérotes sur tubercules prélevés dans des stocks de nombreuses variétés cultivées dans un grand éventail de sol en Ecosse. Des disques de gélose, des souches test ont été utilisés directement pour inoculer des semences de céréales dans la région du collet et pour inoculer des boites de gélose à l'eau du robinet (TWA) ou avec un bouillon de pommes de terre et saccharose. Les broyats de mycélium des bouillons de culture ont été utilisés pour infecter les milieux de croissance de la plante. Les semences de blé et orge ont été examinées 3 semaines après inoculation. Les prélèvements de tissus ont été mis sur les cultures des souches test TWA agées de 3 jours, et la virulence de chaque souche exprimée en tant que fonction de la quantité de tissu végétal décoloré a été mesurée après 7 jours. Les tubercules ont été testés sur des plantes conduites en serre durant 5 mois dans des sols infectés. Quand les souches deR. solani furent testées sur germes en place sur les tubercules, celles provenant des germes. Nos 4 et 8, présentaient un pouvoir pathogène modéré, alors que celles qui étaient issues de sclérotes sur tubercules laissaient apparaitre toute une gamme de pouvoir pathogène (tableau 1). Les fragments de germes isolés des tubercules n'ont pas réagi de la même fa?on (tableau 2), alors que les folioles (tableau 3) et les fragments de tiges n'ont donné de résultats comparables qu'à certaines périodes de l'année. Les resultats obtenus avec les tubercules de pommes de terre furent satisfaisants; une souche infectieuse à leur égard était également hautement pathogène sur les germes (tableaux 4 et 5). D'après les résultats des essais sur blé et orge il ne faut pas s'attendre à avoir de hauts niveaux de germination pour ces deux céréales, lorsqu'elles sont plantées après une récolte de pomme de terre fortement contaminée parR. solani (tableau 6). (Aucune différence significative (P 0.05) fut détectée par le Duncan Multiple Range Test dans les données de toutes tableaux ayant une ligne commune.)