Universiẗat, Diss., 2003--Düsseldorf.

The aim of the study was to evaluate the impact of the application of foliar fertilizers on starch production at potato growing. The literary review contains a general introduction to the topic and furthermore there is a summary of the existing development and production of potatoes both in the Czech Republic and abroad. The results were obtained from the one-year field experiment, during which two potato varieties with different lengths of the growing seasons were planted. It was a medium-early ripening variety Priamos and the late variety Dominator. In 2014 the one-year field experiment was established, during which the effect of the application of the solution of urea, Lignohumate and Energen Fulhum was evaluated compared with the variant without the application of foliar fertilizers. The tuber yield, number of tubers per plant, weight of tubers per plant, average weight of 1 tuber, starch yield and starch content were evaluated. The annual results indicated that the foliar fertilizers had on this year the positive effect on tuber yield, but the impact on the starch yield and content has not been confirmed. Both monitored potato varieties responded positively to the application of Lignohumate - by tuber enlarging. The Priamos Variety had an average tuber yield of 50.3 t/ha and the average starch content of 20.3%. In contrast the variety Dominator had the average tuber yield of 59.8 t/ha but lower starch content, in the average by 17.6%.

The aim of the study was to evaluate the effect of foliar nitrogen nutrition on yield and starch content and protein varieties of potatoes for starch with different length of the growing season. The literary review contains a general introduction to the topic and furthermore there is a summary of the existing development and production of potatoes both in the Czech Republic and abroad. In 2015 it was established one-year field experiment, where the effect was evaluated by 8% urea solution in variations in one application time and application in terms of solution 2 compared to the variant without the application of the urea solution. There were three sorts of potatoes with different vegetation period. It was a medium late variety Zuzanna and semi-late to late varieties Eurogrand and Eurostarch . At very specific 2015 to both precipitation and temperature be best evaluated albeit to a small extent, by the urea solution in the first term. Applications for the 2nd deadline had no significant effect on the production of starch and nitrogen compounds .

No description available.

The aim of this work was to identify potential mRNA targets of PTGS triggered by viroid-derived small RNAs (vsRNAs) in PSTVd-infected tomato plants (S. lycopersicum L.). We selected 47 possible gene targets using data provided by Prof. Dr. Steger (Heinrich Heine Universität, Düsseldorf, Germany) - the list of 1633 possible target mRNAs from tomato based on vsRNA:mRNA duplex prediction. The vsRNA sequences were obtained by Illumina sequencing of small RNA libraries from healthy and PSTVd-infected tomato plants. By qRT-PCR analysis we identified 6 genes with significantly altered levels of mRNA in PSTVd-infected tomato plants: CUL1 (protein ubiquitination), ERF4 (transcription factor of abiotic stress signalling pathway), H/ACA1 (rRNA pseudouridylation), NPH3 (transcription factor of fototropic signalling pathway), Sl-MYB (transcription factor regulating leaf development) and TCP3 (transcription factor regulating leaf development). The binary vector pLV07 with inserted expression cassette containing coding sequence of Sl-MYB was prepared for experiments in ?leaf factory? system in N. benthamiana plants. Expression analyses in ?leaf factory? system after 1,5 DPI using qRT-PCR and RNA blots revealed strong inhibition of expression of Sl-MYB in leaf sectors infiltrated with severe PSTVd AS1 strain, while mild PSTVd QFA strain showed minimal change in expression comparing to control sectors. Moreover, the overexpression of Sl-MYB in leaf sectors resulted in development of necroses after 2,5-3 DPI, in presence of silencing suppressor p19 after 2 DPI. The development of necroses was largely inhibited in PSTVd AS1-infiltrated leaf sectors in comparison with PSTVd QFA- and control-infiltrated sectors.

In this thesis, the effects of year, variety and size of seed tubers on yield and quality of potato tubers were evaluated. In the two years (2011 and 2012), four potato varieties (Velox, Marabel, Adéla and Laura) were used. Size of seed tubers for all varieties was split into three size fractions: A < 35 mm, B 35-60 mm and C > 60 mm. In both years of observation were monitored following parameters: total and marketable yield, average number of stems per plant, number of tubers per plant, number of tubers per stem, the average weight of tuber, proportion of tuber size in harvested tubers, content of dry matter and starch in tubers fresh matter. Year contributed most to the total variability in total and market tuber yield (51.2%. And 54.4%, respectively). Size of seed tubers showed the highest proportion in the total variability of number of stems per plant (94.7%). Declared cooking type in all evaluated varieties was kept. Table value was significantly affected only by variety.

Please read the abstract in the section 00front of this document. Also note that an abstract is provided for each chapter as well / Thesis (DPhil (Entomology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

No description available.

ZUSAMMENFASSUNG Nematoden rufen weltweit erhebliche Verluste in der Kartoffelproduktion hervor. Der Knollenfäule-Nematode Ditylenchus destructor Thorne 1945 und das Stock-und Stangelälchen Ditylenchus dipsaci Kühn 1857 Filipjev, 1936, verursachen Läsionen an der Kartoffelknolle, was deren Qualität und Marktwert verringert. Diese Nematoden sind aufgrund ihres umfangreichen Wirtspflanzenspektrums schwierig zu kontrollieren und werden daher in vielen Ländern als Quarantäne-Nematoden geführt. In der hier vorliegenden Doktorarbeit wurden Experimente durchgeführt, um die Wechselwirkung von Kartoffel mit jeder dieser beiden Nematodenarten zu untersuchen. Verschiedene Populationen von D. destructor und D. dipsaci wurden molekular und morphometrisch charakterisiert. Die Gensequenz kodierend für die Untereinheit I der Cytochrom Oxidase (COI) auf der mitochondrialen DNA (mtDNA) wurde analysiert, um eine phylogenetische Beziehung zwischen den untersuchten Populationen darzustellen. Die Ergebnisse zeigten zwei deutlich getrennte Cluster für die D. destructor und die D. dipsaci Populationen. Eine Diskriminanzanalyse der morphometrischen Daten von Männchen und Weibchen von D. destructor und D. dipsaci Populationen verdeutlichte, dass diese beiden Arten mittels a-ratio und ihrem Durchmesser unterschieden werden können. Die sich ergänzende Kombination von molekularen und morphometrischen Untersuchungen ermöglichte die Identifikation der untersuchten Arten. Es wurden zwei Gewächshausexperimente mit 25 angebauten Kartoffelsorten durchgeführt, um diese auf Resistenz und Toleranz gegenüber Nematoden zu testen. Dazu wurde ein Standard-Screening Protokoll entwickelt. Resistenz und Toleranz wurden gemäß der derzeitigen Definition (Nematologie) bewertet. Die relative Anfälligkeit und äußere Verletzung der Kartoffelknolle stellten sich als beste Parameter für die Beurteilung der Resistenz respektive der Toleranz heraus. Alle 25 untersuchten Kartoffelsorten waren weder resistent noch tolerant gegenüber D. destructor oder D. dipsaci. Jedoch wurden Unterschiede in der Toleranz der Sorten festgestellt. Im Vorfeld zum Pflanzenexperiment wurden die Populationsdichten von D. destructor und D. dipsaci und deren Einfluss auf Ertragsverlust untersucht. Die initiale Populationsdichte hatte einen signifikanten Effekt auf den Schaden an der Kartoffelknolle und den Fortpflanzungsfaktor der Nematoden unter Gewächshausbedingungen. D. destructor verursachte Schäden bereits bei einer geringeren initialen Populationsdichte als D. dipsaci. Unter Klimakammerbedingungen wurde gezeigt, dass die Temperatur Einfluss auf die Schadensrate von D. destructor und D. dipsaci an Kartoffelknollen nimmt. Im Gegensatz zu einer Temperatur von 16°C waren 26°C sowohl optimal für die Vermehrung von D. destructor als auch für D. dipsaci. Obwohl für D. destructor und D. dipsaci unterschiedliche Temperaturanforderungen beschrieben wurden, verursachten beide Arten in ähnlichen Temperaturbereichen äußere Verletzungen an der Kartoffelknolle. Beauveria bassiana ist ein weltweit verbreiteter Pilz, der vor allem zur Bekämpfung von Insektenschädlingen in der Kartoffelproduktion Anwendung findet. Doppelbefall von Kartoffeln mit B. bassiana Sporensuspensionen im Boden mit D. destructor oder D. dipsaci begünstigte die Nematoden, was zu einer erhöhten Nematodenfortpflanzung und Knollenbeschädigung führte. B. bassiana allein war nicht schädlich für die Kartoffel. Es wurde vermutet, dass B. bassiana eine indirekte Rolle in der Wechselwirkung Nematode-Kartoffel spielt. Vorschläge für zukünftige Experimente werden angebracht, die einen weiteren Beitrag zu den hier vorgestellten Studien leisten können.

Os diferentes taxa de Arrojadoa exibem uma variedade de estruturas subterrâneas, tanto de origem caulinar como radicular. O desenvolvimento de estruturas subterrâneas de origem caulinar em Arrojadoa é uma característica única entre as Cactaceae do leste do Brasil. No entanto, não há estudos sobre a diversidade morfológica das estruturas subterrâneas encontradas neste gênero, nem na sua utilidade para ajudar a resolver a taxonomia do grupo. Por isso, foi realizada uma investigação morfológica e anatômica das estruturas subterrâneas em doze taxa de Arrojadoa sensu lato. Para a análise anatômica, amostras das regiões apical, mediana e basal das diferentes estruturas subterrâneas foram fixadas em FAA 50 (formaldeído, ácido acético glacial e etanol 50º GL) e armazenadas em etanol 70º GL. Seções transversais e longitudinais foram realizadas com uso de micrótomo rotativo e à mão. O gênero revelou uma grande diversidade de estruturas subterrâneas: tubérculos simples e ramificados, caules subterrâneos curtos, caules subterrâneos longos (sóboles), raízes contráteis (estas espessadas) e raízes comuns (fibrosas e não fibrosas); sendo que uma mesma espécie pode apresentar mais de um tipo de estrutura em seu sistema subterrâneo. O estudo morfológico propõe que sejam reconhecidas oito espécies e cinco subespécies de Arrojadoa, além de uma espécie de colocação genérica duvidosa. Quanto às análises anatômicas este estudo confirmou a natureza caulinar dos tubérculos, sóboles e caules subterrâneos curtos, sendo que apenas no tubérculo de A. hofackeriana foi verificada a participação da região de transição na sua estrutura. Também foi observado, nas raízes espessadas (raízes contráteis) de Arrojadoa um mecanismo de contração semelhante ao relatado para outra espécie da família, sendo o xilema secundário com lenho \"WBT\" (\"wide-band tracheids\") o principal tecido responsável pelo espessamento do órgão. Já nos caules (tubérculos, sóboles e caules curtos), embora haja uma contribuição do parênquima no xilema secundário com o lenho do tipo \"WBT\" e/ou associado a elementos de vaso, a região cortical é responsável pela maior parte do espessamento do órgão relacionado à suculência e armazenamento. / The different Arrojadoa taxa display variety of underground structures, formed both from the stem and the root. The development of these structures from stem in Arrojadoa is unique among the Cactaceae of the East of Brazil. However, there are no studies about the morphologic diversity of underground structures found in this genus, or about their use to help solve the group taxonomy. Thus, a morphologic and anatomic investigation of the underground structures was made in twelve taxa of Arrojadoa sensu lato. For the anatomical analysis, samples of the apical, median and basal portions of the different underground structures were fixed in FAA 50 (formaldehyde, glacial acetic acid and ethanol 50º GL), and stored in ethanol 70º GL. Longitudinal and transversal sections were made with rotative microtome and by free-hand. The genera revealed a great diversity of underground structures: simple and branched tubers, short underground stem, long underground stem (soboles), contractile roots (thickened) and common roots (fibrous and non-fibrous); and the same species can display more than one type of structure in its underground system. The morphologic study proposes that should be recognized eight species and five sub-species of Arrojadoa, besides one that is dubious in the genera aspect. About the anatomical analysis, this study confirmed the stem origin of the tubers, soboles and short underground stem, and only in the A. hofackeriana tuber it was observed the participation of the root-stem transition region. It was also observed in the thickened roots (contractile roots) of Arrojadoa a contraction mechanism similar to what is reported to other species of the family, with the secondary xylem with WBT (wide-band tracheids) wood the major responsible for thickening of the organ. In the stems (tubers, soboles and short stems), although the parenchyma contributes with the secondary xylem with the WBT and/or associated with vessel elements, the cortical region is the responsible for mostly all thickening of the organ related to succulence and storage.