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First record of the leafhopper Hishimonus hamatus Kuoh, 1976 (Hemiptera: Cicadellidae) in Germany
Get PDFWährend einer Erhebung in Weinbauregionen von Rheinland-Pfalz in Deutschland zum Vorkommen von Zikaden, die als Vektor für Phytoplasmen eine Rolle spielen, wurden bei Neustadt a. d. Weinstraße einige Individuen von Hishimonus hamatus gefangen. Die Tiere wurden mittels Handfang und Gelbtafel-Klebefallen an Sträuchern gesammelt. Die Bestimmung der Art erfolgte visuell und molekulargenetisch. Es ist der Erstnachweis von H. hamatus für Deutschland und nördlich der Alpen, was auf eine weitere Ausbreitung dieser Art in Europa hinweist.When monitoring leafhoppers for phytoplasma vector management in the grapevine growing regions of Rhineland-Palatinate, Germany, some individuals of Hishimonus hamatus were collected at Neustadt a. d. Weinstraße. Specimen were caught by net as well as with Yellow Sticky Traps placed in shrubs. The species was determined visually and verified by molecular analysis. This is the first record of H. hamatus in Germany and also north of the Alp mountains denoting that this species is further expanding its territory in Europe
Diverse and strain-specific metabolites patterns induced by fungal endophytes in grape cells of different varieties
Get PDFThe potential for endophytes to initiate changes in host secondary metabolism has been well documented. However, the mechanisms underlying endophyte-plant metabolic interactions are still poorly understood. Here, we analysed the effects of fungal endophytes on the metabolite profiles of grape cells from two cultivars: \u27Cabernet Sauvignon\u27 (CS) and \u27Rose honey\u27 (RH). Our results clearly showed that co-culture with endophytic fungi greatly modified the metabolic profiles in grape cells of both varieties. Treatments with endophytic fungal strains caused the numbers of detected metabolites to vary from 10 to 19 in CS cells and from 8 to 14 in RH cells. In addition, 5 metabolites were detected in all CS cell samples, while 4 metabolites were detected in all RH cell samples. Some endophytic fungal strains could even introduce novel metabolites into the co-cultured grape cells. The metabolic profiles of grape leaves shaped by endophytic fungi exhibited host selectivity and fungal strain specificity. In this assay, the fungal strains RH32 (Alternaria sp.) and MDR36 (Colletotrichum sp.) triggered an increased response of the detected metabolites, including the greatest increase in the metabolite contents in grape cells of both cultivars. No obvious effects in terms of metabolite numbers and contents in grape cells when co-cultured with fungal strains RH7 (Epicoccum sp.) and RH48 (Colletotrichum sp.) were observed. The results of this experiment suggest that endophytic fungi could be used to control the metabolic profiles of grapes and thus increase grape quality
Evaluation of different native Streptomyces spp. for effective management of rhizome rot of turmeric
Get PDFThe efficacy of talc based bioformulations containing various biocontrol agents against rhizome rot disease caused by Pythium aphanidermatum in turmeric plants was evaluated under field condition. Indigenous biocontrol agents such as Streptomyceslydicus, Streptomyces griseus and Streptomyces sannanensis belonging to actinomycetes group, Pseudomonas fluorescens (bacterial) and Trichoderma atroviride (fungal) were selected for the biological control of rhizome rot of turmeric. The results indicated a significantly stronger reduction in disease severity in trial plots treated with Bacillus subtilis based commercial fungicide ‘Companion’ when compared to plants treated with indigenous biocontrol agents. However, it was reverse in trial plots in terms of turmeric rhizome yield potential, yield attributes, physiological components, biochemical constituents and quality characteristics of rhizomes. Among 17 treatments, a dual mixture of S. griseus and T. atroviride achieved the best disease control as well as plant growth improvement when compared to single and triple combinations of biocontrol agents. The present study confirms that exploration of microbial formulations containing Streptomyces spp.as soil inoculant to turmeric plants exhibited some benefits to turmeric plant growth as well as controlling rhizome rot disease, which ultimately enhance the overall quality characteristics of rhizomes. Further, our results suggest that a dual combination of biocontrol agents represent a promising method for effective management of rhizome rot of turmeric
Evaluating the practicability of commercial food-scanners for non-destructive quality assessment of tomato fruit
Get PDFThe assessment of tomato fruit quality depends on a variety of extrinsic and intrinsic quality parameters such as color, firmness and sugar content. Conventional measurement methods of these quality parameters are time consuming, require various measurement de-vices, and in case of intrinsic quality, involve destructive measurements. Latest research focused on the non-destructive determination of these parameters by using spectroscopic measurements. The goal of this study was to evaluate the capability of three commercially available portable and miniaturized VIS /NIR spectrometers, so called food-scanners, in predicting various tomato quality attributes in a non-destructive way. Additionally, this study evaluated the software provided by manufacturers for building of prediction models by comparing the results derived from those software tools to state-of-the-art software for multivariate analysis. Evaluation of food-scanner spectra resulted in prediction models of high accuracy (r² > 0.90) for tomato fruit firmness, dry matter, total soluble solids and color values L*, a* and h°. Prediction models computed with manufacturer’s soft-ware showed similar accuracy to those derived from state-of-the-art evaluation software. Results of this study illustrate the great potential of commercial food-scanners for non-destructive quality measurement. Further important features of food-scanners with respect to the application along the fresh produce supply chain are addressed
High-resolution mapping of a QTL for Fusarium Head Blight resistance on chromosome 2A in Triticum monococcum
Get PDFDie Sicherstellung und Erhöhung des Weizenertrags hat heutzutage weltweit große Bedeutung, um die Ernährung der stetig wachsenden Gesellschaft zu sichern. Eine sehr bedeutende Krankheit im Weizen ist die Ährenfusariose (engl. Fusarium Head Blight, FHB), die durch verschiede Fusarium spp.- Pilze hervorgerufen wird. Diese kann zu Ertragsverlusten bis zu 40 % führen und durch die Bildung von Mykotoxinen während des Infektionszyklus, die Qualität mindern sowie die Gesundheit von Mensch und Tier gefährden. In der folgenden Studie wurde das Resistenzverhalten im Einkorn (Triticum monococcum) gegenüber Fusarium untersucht. Dazu wurde eine DH-population, bestehend aus 94 DH-Linien, erstellt und analysiert, die auf eine Kreuzung zwischen Triticum monococcum L. (mon10-1: moderates Resistenzverhalten) und Triticum monococcum L. conv. sinskayae (Sinskayae: anfällig) zurückgeht. Die DH-Population wurde in zweijährigen Feldversuchen phänotypisiert und mit DArT und SSR-Markern genotypisiert, was in einer genetischen Karte von 1987.55 cM resultierte. In einer anschließenden QTL-Analyse wurden zwei benachbarte QTL auf Chromosom 2A in einem Intervall von 45.1 cM (31.4 Mbp) kartiert. Mit der Methode der kartengestützten Genisolierung wurde das QTL Intervall verkleinert um eng gekoppelte Marker oder Kandidatengene zu identifizieren, die diese Variation bewirken. Dazu wurde eine hochauflösende Kartierungspopulation, bestehend aus 1991 F2-Pflanzen erstellt, die auf eine Kreuzung zwischen zwei resistenten und drei anfälligen DH-Linien der ursprünglichen DH-Population zurückgeht. Es konnten 333 rekombinante Inzuchtlinien (RIL) identifiziert werden. Von diesen wurden 268 RILs in Gewächshaus- und Feldversuchen mit dem Fusarium-Isolat Fc46 phänotypisiert und mit 21, durch genotyping-by-sequencing (GBS), den 90K iSelect Chip und der genetischen Karte von Triticum monococcum, neu entwickelten KASP-Markern genotypisiert. Dennoch war es nicht möglich den Resistenzlocus innerhalb des Intervalls zu kartieren. Eine neue QTL-Analyse mit den physikalischen Positionen eines reduzierten Markersets aus der ursprünglichen DH-Population zeigte, dass sich die Peak-Marker in eine Region zwischen 499.25 – 607.96 Mbp verschieben. Ebenfalls wird das sog-Gen in dieser Region vermutet, welches verantwortlich für die Ährenform von Triticum sinskayae ist. Es ist unklar, ob der beobachtete Effekt durch eine enge Kopplung beider Gene in dieser genomischen Region hervorgerufen wird oder durch Pleiotropie.Securing wheat production is of prime importance with regard to feeding the earth’s growing population. Wheat is threatened by a lot of abiotic and biotic factors leading to severe yield losses. One important disease is Fusarium Head Blight (FHB), caused by different Fusarium spp. The disease leads to yield losses up to 40 %, a reduction in quality and a health risk for mankind due to toxic secondary metabolites that arise during the infection process. Therefore, FHB belongs to the most important wheat diseases and is extensively studied worldwide. To improve resistance of wheat to Fusarium spp., this study was conducted to get detailed information on the genetics of a new source of resistance, detcted in Triticum monococcum, which is a close relative of bread wheat. To achieve this, a DH-population based on a cross between Triticum monococcum accession mon10-1, which is moderately resistant to FHB and the FHB susceptible Triticum monococcum L. conv. sinskayae (Sinskayae) comprising of 94 DH-lines was analysed. The population was phenotyped in two years field trials and genotyped by DArT analyses resulting in a genetic map of 1987.55 cM. Based on these data, two neighbouring QTLs were mapped in an interval of 45.1 cM on the short arm of chromosome 2A. Further analyses aimed at shortening the QTL interval and the identification of closely linked markers and candidate genes by a map-based cloning approach. A high-resolution mapping population was developd out of 1991 F2-plants, that traced back to crosses between three susceptible and two resistant DH-lines of the original population. 333 RILs were developed of which 268 were used for phenotypic evaluation with F. culmorum (Isolate: Fc46) in field and greenhouse trials. Marker saturation was conducted based on the 90K iSelect chip, genotyping-by-sequencing (GBS) and known genetic maps of Triticum monococcum. Out of these, 21 KASP markers were developed and mapped within the QTL interval. Assigning these markers to the physical map of T. aestivum resulted in an interval of 31.4 Mbp. However, by phenotyping respective segmental RILs, the resistance locus was not located within this interval. A new QTL analysis with a reduced marker set of the DH-mapping population using their physical postitions was conducted and resulted in a switch of the peak markers to a proximal region of chromosome 2A into an interval between 499.25 – 607.96 Mbp. This QTL mapped in the same region like the soft glume (sog)-gene, but it is unclear if the QTL effect is due to tight linkage between sog- and FHB resistance gene or pleiotropy
Application of different analytical methods for the determination of phenols and antioxidant activity in hawthorn (Crataegus spp.) bud and sprout herbal extracts
No full textHawthorn (Crataegus spp., family: Rosaceae) extracts have been used as pharmaceutical preparations owing to positive effects on cardiovascular system. The AlCl3-based official method employed for the determination of pharmacologically active compounds was compared with other techniques such as Folin-Ciocalteau method and HPLC-DAD. Antioxidant activity was determined by ABTS radical cation assay. Methods were applied on extracts from buds and sprouts collected from common hawthorn (C. monogyna Jacq., C. laevigata (Poir.) DC.) located in Northeastern Italy. Phenolic content determined by AlCl3-based method, Folin-Ciocalteau method, and HPLC-DAD was in the range 23,534-27,728, 75,284-100,616 and 57,317-58,639 mg kg-1 of dry matter (DM), respectively, in buds, and 17,280-19,330, 27,653-38,590, and 30,635-32,185 mg kg-1 DM, respectively, in sprouts. Antioxidant activity ranged from 119,864 to 174,640 and 31,484 to 52,584 mg Trolox eq. kg-1 DM in buds and sprouts, respectively. Phenolic amount and profile were significantly affected by phenological stage and sampling location. Antioxidant activity was related to flavan-3-ol and hydroxycinnamic acid amount, and to non-phenolic substances. AlCl3-based method underestimated total phenolic content owing to lack of selectivity to important phenolic classes whereas Folin-Ciocalteau method was affected by non-phenolic interfering substances. HPLC-DAD proved to be more effective in determining hawthorn phenolics
Possibilities and limits of chemical weed control in potato cultivation
Get PDFDie Pflanzenschutzdienste von Bayern, Baden-Württemberg, Rheinland-Pfalz und Hessen führten von 2012 bis 2018 ein Ringversuchsprogramm zur Prüfung neuer Herbizide im Kartoffelbau durch. An 26 Versuchsstandorten wurden 13 verschiedene Herbizidbehandlungen hinsichtlich Unkrautbekämpfungsleistung und Kulturverträglichkeit geprüft. An den Versuchsstandorten traten regelmäßig vier unterschiedliche Leitunkräuter auf. Die häufigsten Unkräuter waren Gänsefuß-Arten (CHESS), Winden-Knöterich (POLCO), Einjähriges Bingelkraut (MERAN) und Schwarzer Nachtschatten (SOLNI). Im Mittel über alle Standorte und Behandlungsvarianten wurde mit 94 % eine ausreichende Gesamt-Unkrautwirkung erzielt. Wichtige Leitunkräuter wie Gänsefuß-Arten (CHESS), Behaartes Franzosenkraut (GASCI), Hühnerhirse (ECHCG) und Kletten-Labkraut (GALAP) konnten mit mittleren Wirkungsgraden von ³ 97 % sicher kontrolliert werden. In Abhängigkeit von einzelnen Behandlungsvarianten und Standorten konnten die Unkräuter Einjähriges Bingelkraut (MERAN) und Winden-Knöterich (POLCO) dagegen nicht mehr sicher bekämpft werden. Schwarzer Nachtschatten (SOLNI) kann als generelles Problemunkraut im Kartoffelbau bezeichnet werden. Die Kulturverträglichkeit der geprüften Herbizid-Kombinationen kann als gut bis sehr gut bezeichnet werden. Einzelne beobachtete, kurzfristige Kulturbeeinträchtigungen waren auf Standorteffekte zurückzuführen.From 2012 to 2018, the plant protection services of Bavaria, Baden-Württemberg, Rhineland-Palatinate and Hesse carried out an interlaboratory test programme for the testing of new herbicides in potato cultivation. At 26 experimental sites, 13 different herbicide treatments were tested for weed control performance and crop compatibility. Four different common weeds regularly appeared at each experimental site. The most common weeds were goosefoot (CHESS), wild buckwheat (POLCO), annual mercury (MERAN) and black nightshade (SOLNI). On average across all locations and treatment options, 94% of the total weed control efficacy was sufficient. Important common weeds such as goosefoot, hairy galinsoga (GASCI), barnyardgrass (ECHCG) and cleavers (GALAP) could be safely controlled with average efficiencies of ³ 97%. Depending on the individual treatment options and locations, however, annual mercury and wild buckwheat could no longer be controlled safely. Black nightshade (SOLNI) can be described as a general problem weed in potato cultivation. The culture tolerance of the tested herbicide combinations can be described as good to very good. Individual short-term cultural impairments observed were attributable to location effects
Generation of weed distribution maps based on automatic annotations in field images
Get PDFModerne Applikationstechnik, wie z. B. Mehrkammersysteme, ermöglicht inzwischen sowohl eine an die räumlich variable Unkrautverteilung angepasste Herbizidaufwandmenge als auch die Herbizidwahl. Für die Umsetzung einer solchen teilflächenspezifischen Applikation ist neben einem geeigneten Pflanzenschutzgerät auch die Integration von Metainformationen zur exakten Charakterisierung von Teilflächen und zur Berücksichtigung von Abstandsauflagen in Randbereichen sinnvoll. Dazu wird zurzeit ein Assistenzsystem entwickelt, das unter anderem auch Informationen über die Unkrautverteilung beinhaltet. Ein möglicher Ansatz, die für eine teilflächenspezifische Herbizidapplikation notwendigen Unkrautverteilungskarten zu generieren, ist die objektbasierte Analyse von georeferenzierten Bilddaten unter Verwendung von Modellen des maschinellen Lernens. Beispielhaft wurde ein Bag-of-Visual-Words (BoVW) Ansatz für die Erkennung von Unkrautarten in Luftbildaufnahmen aus UAV-Befliegungen (unmanned aerial vehicle) erfolgreich angewendet. Zur Erstellung von Unkrautverteilungskarten mit umfassenderem Unkrautartenspektrum ist jedoch die Analyse größerer Datensätze notwendig, für die die Verwendung von deep learning Algorithmen erforderlich ist. Die Eignung dieser Algorithmen wurde in dieser Studie unter Verwendung von convolutional neural nets (CNN)s anhand von Bildaufnahmen aus Feldversuchen überprüft. Dabei zeigte sich, dass die Präzision des verwendeten Klassifikators, mit Ausnahme von Ehrenpreis-Arten (VERSS), für die jeweiligen Klassen bei über 84 % lag. Bei Anwendung der CNN-Modelle auf Aufnahmen aus geringer Höhe konnte ermittelt werden, dass sich die getesteten Algorithmen grundsätzlich für eine Vorhersage der richtigen Pflanzen- bzw. Bodenkategorie eignen. Bei einem geringen Anteil von Acker-Fuchsschwanzpflanzen (ALOMY) in den Aufnahmen wurde jedoch der vorhergesagte Flächenanteil von ALOMY deutlich überschätzt.Modern application systems, e.g. multi-chamber systems, now allow the choice of herbicides and herbicide dose rates, which are adapted to a spatially variable weed distribution. Besides suitable plant protection equipment, the implementation of site-specific application requires the integration of the large amount of information that characterises an individual site. For this purpose an assistance system is being developed, which will also contain information about weed distribution. One approach to generate weed distribution maps, which are essential for site-specific herbicide application, is the use of models based on machine learning. Such a Bag-of-Visual-Word (BoVW) approach was already applied on UAV (unmanned aerial vehicle) images and successfully used for the recognition of few weed species. To generate weed distribution maps with a larger weed spectrum, however, the analysis of larger data sets is necessary, which requires the use of deep learning algorithms. The suitability of these algorithms was tested in this study applying convolutional neural nets (CNN)s to images generated in field trials. The classifier showed an overall accuracy of >84%, except for speedwell species (VERSS). When applying the CNN models on images acquired at low altitudes, it was shown that the tested algorithms are generally suitable for a correct prediction of different plant and soil classes. However, if the amount of black-grass (ALOMY) present in the images was low, the predicted area size for ALOMY was significantly overestimated
Reduced efficacy of glyphosate against annual fescue (Vulpia myuros)
Get PDFIm Rahmen der alljährlichen Untersuchung von Verdachtsproben auf Herbizidresistenz aus Rheinland-Pfalz wurde 2018 eine Population des Mäuseschwanz-Federschwingels (Vulpia myuros L.) in einem Weinbaubetrieb in Rheinhessen gesammelt. Er wandert regelmäßig aus den Feldrainen in die herbizidbehandelten Rebzeilen ein. In mehreren Biotesten am Dienstleistungszentrum Ländlicher Raum (Bad Kreuznach) und an der Bayerischen Landesanstalt für Landwirtschaft (Freising) konnte in den Jahren 2018 und 2019 nur eine unzureichende Wirkung von Glyphosat erzielt werden. Es besteht der begründete Verdacht auf eine nachlassende Sensitivität bzw. beginnende Resistenz gegenüber Glyphosat in der untersuchten Population aufgrund des langjährigen und wiederholten Einsatzes von Glyphosat. Weitere Untersuchungen sind erforderlich um die Ursache für die Minderwirkungen zu ermitteln.In 2018, numerous weed seed samples were taken from fields within Rhineland-Palatinate (Germany) where herbicide resistance was suspected. One sample of annual fescue (Vulpia myuros L.) was collected in a wine-growing estate in Rhinehessen. Annual fescue frequently emigrates from the field margins into the wine rows. By conducting several bioassays at the Dienstleistungszentrum Ländlicher Raum (Bad Kreuznach, Rhineland-Palatinate) and at the Landesanstalt für Landwirtschaft (Freising, Bavaria) a poor efficacy of glyphosate was observed. There is a reasonable suspicion that repeated, long-time use of glyphosate might be the reason for a decreasing sensitivity or an evolving resistance in the myuros population investigated. Additional investigations are necessary to determine potential mechanisms involved in reduced herbicide sensitivity