A Hyperspectral Library of Foliar Diseases of Wheat

2021 ◽  
Author(s):  
David Bohnenkamp ◽  
Jan Behmann ◽  
Stefan Paulus ◽  
Ulrike Steiner ◽  
Anne-Katrin Mahlein
Keyword(s):  
Developmental Stages ◽  
Leaf Tissue ◽  
Plant Diseases ◽  
Identification System ◽  
Spectral Library ◽  
Foliar Diseases ◽  
Robust Detection ◽  
Analysis Methods ◽  
Detection And Identification ◽  
Biotrophic Fungi

This work established a hyperspectral library of important foliar diseases of wheat in time series to detect spectral changes from infection to symptom appearance induced by different pathogens. The data was generated under controlled conditions at the leaf-scale. The transition from healthy to diseased leaf tissue was assessed, spectral shifts were identified and used in combination with histological investigations to define developmental stages in pathogenesis for each disease. The spectral signatures of each plant disease that are indicative of a certain developmental stage during pathogenesis - defined as turning points - were combined into a spectral library. Different machine learning analysis methods were applied and compared to test the potential of this library for the detection and quantification of foliar diseases in hyperspectral images. All evaluated classifiers provided a high accuracy for the detection and identification for both the biotrophic fungi and the necrotrophic fungi of up to 99%. The potential of applying spectral analysis methods, in combination with a spectral library for the detection and identification of plant diseases is demonstrated. Further evaluation and development of these algorithms should contribute to a robust detection and identification system for plant diseases at different developmental stages and the promotion and development of site-specific management techniques of plant diseases under field conditions.

scholarly journals A new approach for three component seismic array processing

1994 ◽  
Vol 37 (3) ◽  
Author(s):  
O. K. Kedrov ◽  
V. E. Permyakova
Keyword(s):  
Noise Suppression ◽  
Effective Means ◽  
Seismic Arrays ◽  
Robust Detection ◽  
Detection And Identification ◽  
Seismic Vibrations ◽  
Band Pass ◽  
Polarization Filtering ◽  
Detection Of Signals ◽  
New Procedures

The new concept and methodology of regional seismic arrays (RSA) equipped by three component (3 C) sensors (Z, NS, EH9, are proposed. Such system could be more perfect tool of Earth interior investigations. This aim can be achieved by introduction of polarization filtering of 3 C seismic vibrations as an effective means of noise suppression and robust detection and identification of secondary body phases of the signals. The proposed algorithm is based on: 1) linear phase band pass frequency filtering of N 3 C records in M bands; 2) polarization filtering of all 3 C records in all L directions where array beams are routinely oriented; 3) calculation of L beams in M bands using polarized P, SV and SH traces of individual sensors; 4) detection of signals on the L*M P, SV and SH traces; 5) location of the event. The main new procedures are 2) and 3). Due to these new approaches the procedures 4) and 5) will be improved in comparison with,those routinely used today at RSA's. This work includes the theoretical consideration of proposed method efficiency and preliminary experimental results.

scholarly journals First Report of Downy Mildew Caused by Plasmopara obducens on Impatiens in California

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 909-909 ◽  
Author(s):  
S. N. Wegulo ◽  
S. T. Koike ◽  
M. Vilchez ◽  
P. Santos
Keyword(s):  
United States ◽  
Downy Mildew ◽  
Disease Incidence ◽  
Leaf Tissue ◽  
The United States ◽  
Plant Diseases ◽  
Single Type ◽  
First Report ◽  
Commercial Grower ◽  
Impatiens Walleriana

During February 2004, diseased double impatiens (Impatiens walleriana) plants were received from a commercial grower in southern California. The upper surfaces of symptomatic leaves were pale yellow with no distinct lesions. Diseased leaves later wilted, and severely affected leaves abscised from the stem. At the nursery, only double impatiens plants in the Fiesta series were infected, and some cultivars were more heavily infected than others. Disease incidence in cv. Sparkler Hot pink was nearly 100%. The interior of infected leaves was colonized by coenocytic mycelium. A conspicuous white growth was observed only on the underside of leaves. Sporangiophores were hyaline, thin walled, emergent from stomata, and had slightly swollen bases. Sporangiophore branching was distinctly monopodial. Smaller sporangiophore branches were arranged at right angles to the supporting branches, and tips of branches measured 8 to 14 μm long. Sporangia were ovoid and hyaline with a single pore on the distal ends. Distal ends of sporangia were predominantly flat but occasionally had a slight papilla. Short pedicels were present on the attached ends. Sporangia measured 19.4 to 22.2 (-25.0) μm × 13.9 to 16.7 (-19.4) μm. Oospores were not observed in leaf tissue. On the basis of symptoms and morphology of the organism, the pathogen was identified as Plasmopara obducens J. Schröt. Pathogenicity tests were done on double type cvs. Fiesta, Tioga Red, and Tioga Cherry Red and on single type cvs. Cajun Watermelon and Accent Lilac. Plants were spray inoculated with sporangiospore suspensions (1 × 104 sporangiospores per milliliter), incubated for 24 h in a dew chamber (18 to 20°C), and then maintained in a greenhouse (22 to 24°C). Symptoms and signs of downy mildew developed after 12 days only on inoculated cv. Fiesta plants, and the pathogen morphology matched that of the originally observed pathogen. Nontreated control plants did not develop downy mildew. To our knowledge, this is the first report of downy mildew on impatiens in California. P. obducens is one of two causal agents of downy mildew of impatiens (2,4). The other pathogen, Bremiella sphaerosperma, has dichotomous sporangiophore branching and causes lesions with well-defined margins (2,4). In the United States, the disease has been recorded in the eastern and northeastern states and in Indiana, Minnesota, Mississippi, Montana, and Wisconsin (3). In Canada, the disease has been recorded in Manitoba and Quebec (1). References: (1) I. L. Conners. An Annotated Index of Plant Diseases in Canada and Fungi Recorded on Plants in Alaska, Canada, and Greenland. Research Branch, Canada Department of Agriculture, Publication 1251, 1967. (2) O. Constantinescu. Mycologia 83:473, 1991. (3) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, 1989. (4) G. W. Wilson. Bull. Torrey Bot. Club 34:387, 1907.

scholarly journals Detection and Identification of Microbial Volatile Organic Compounds of the Green Mold Disease

2020 ◽  
Vol 11 (2) ◽  
pp. 14-28
Author(s):  
Dalma Radványi ◽  
András Geösel ◽  
Zsuzsa Jókai ◽  
Péter Fodor ◽  
Attila Gere
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Identification System ◽  
Mushroom Species ◽  
Detection And Identification ◽  
Volatile Organic ◽  
Microbial Volatile Organic Compounds ◽  
Green Mould

Button mushrooms are one of the most commonly cultivated mushroom species facing different risks e.g.: viral, bacterial and fungal diseases. One of the most common problems is caused by Trichoderma aggressivum, or ‘green mould' disease. The presence or absence of mushroom disease-related moulds can sufficiently be detected from the air by headspace solid-phase microextraction coupled gas chromatography-mass spectrometry (HS SPME GC-MS) via their emitted microbial volatile organic compounds (MVOCs). In the present study, HS SPME GC-MS was used to explore the volatile secondary metabolites released by T. aggressivum f. europaeum on different nutrient-rich and -poor media. The MVOC pattern of green mould was determined, then media-dependent and independent biomarkers were also identified during metabolomic experiments. The presented results provide the basics of a green mould identification system which helps producers reducing yield loss, new directions for researchers in mapping the metabolomic pathways of T. aggressivum and new tools for policy makers in mushroom quality control.

Use of Allozyme Electrophoresis for identifying two species of Penaeid Prawn Postlarvae

1990 ◽  
Vol 41 (2) ◽  
pp. 259 ◽  
Author(s):  
S Lavery ◽  
D Staples
Keyword(s):  
Species Identification ◽  
Developmental Stages ◽  
Genetic Differences ◽  
Identification System ◽  
Allozyme Electrophoresis ◽  
Field Sampling ◽  
Penaeid Prawn

Allozyme electrophoresis was used to identify the postlarvae of two species of tiger prawns, Penaeus esculentus and P. semisulcatus, from the Gulf of Carpentaria, Australia. The two species were examined for genetic differences at 39 loci, in three developmental stages (adult, juvenile and postlarval). One locus, Gpi, was suitable for the routine species identification of postlarvae. The electrophoretic identification system developed, when applied to the identification of postlarvae taken by field sampling, was more reliable and efficient than standard morphological techniques.

Dynamics of the Tissue-Specific Metabolism of Luteolin Glucuronides in the Mesophyll of Rye Primary Leaves (Secale cereale)

1988 ◽  
Vol 43 (3-4) ◽  
pp. 187-193 ◽  
Author(s):  
Margot Schulz ◽  
Gottfried Weissenböck
Keyword(s):  
Cinnamic Acid ◽  
Secale Cereale ◽  
Leaf Development ◽  
Glucuronic Acid ◽  
Developmental Stages ◽  
Leaf Tissue ◽  
Feeding Experiments ◽  
Secale Cereale L ◽  
Hydrolysis Of

Developing primary leaves of Secale cereale L. exhibit a dynamic metabolism of the major flavonoid luteolin 7-O-[β-ᴅ-glucuronosyl(1→2)β-ᴅ-glucuronide]-4′-O-β-ᴅ-glucuronide (R1). Final steps of R, biosynthesis are sequential glucuronidations of luteolin, which are catalyzed by three specific UDP-glucuronate: flavone glucuronosyltransferases. These enzymes reach highest activities at the fourth and fifth day of leaf development, coinciding with maximal R, accumulation. The activities decrease with advancing age of the leaves. In contrast, a R1-specific β-glucuronidase, responsible for the hydrolysis of glucuronic acid in position 4′, shows increasing activity up to the 5th or 6th day; but this activity, leading to luteolin 7-O-diglucuronide (R2), is not reduced in later developmental stages. In this phase of leaf development, the amount of R, drastically drops, whereas R2 accumulates only slightly. From in vitro results and from feeding experiments using [14C]cinnamic acid, a precursor of R, biosynthesis, we conclude that the anabolic sequential glucuronidation takes place in young and expanding leaf tissue, whereas deglucuronidation occurs in nearly mature and mature tissue. The three glucuronosyltransferases as well as the β-glucuronidase, and the flavonoids R1 and R2 are localized in the mesophyll.

Performance Comparison of VSI Switches Faults Analysis Using STFT and S Transform

2015 ◽  
Vol 785 ◽  
pp. 210-214 ◽  
Author(s):  
M. Manap ◽  
A.R. Abdullah ◽  
N.Z. Saharuddin ◽  
N.A. Abidullah ◽  
Nur Sumayyah Ahmad ◽  
...  
Keyword(s):  
Power Converter ◽  
Performance Comparison ◽  
Voltage Source ◽  
Percentage Error ◽  
Identification System ◽  
Time Frequency ◽  
Signal Parameters ◽  
Detection And Identification ◽  
Frequency Representation ◽  
S Transform

Switches fault in power converter has become compelling issues over the years. To reduce cost and maintenance downtime, a good fault detection technique is an essential. In this paper, the performance of STFT and S transform techniques are analysed and compared for voltage source inverter (VSI) switches faults. The signal from phase current is represented in jointly time-frequency representation (TFR) to estimate signal parameters and characteristics. Then, the degree of accuracy for both STFT and S transform are determined by the lowest value of mean absolute percentage error (MAPE). The results demonstrate that S transform gives better accuracy compare to STFT and is suitable for VSI switches faults detection and identification system.

scholarly journals Identification of Leishmania by Matrix-Assisted Laser Desorption Ionization–Time of Flight (MALDI-TOF) Mass Spectrometry Using a Free Web-Based Application and a Dedicated Mass-Spectral Library

2017 ◽  
Vol 55 (10) ◽  
pp. 2924-2933 ◽  
Author(s):  
Laurence Lachaud ◽  
Anna Fernández-Arévalo ◽  
Anne-Cécile Normand ◽  
Patrick Lami ◽  
Cécile Nabet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Leishmania Donovani ◽  
Identification System ◽  
Enzyme Electrophoresis ◽  
Mass Spectral Library ◽  
Spectral Library ◽  
Web Based ◽  
Content Type ◽  
Mass Spectral ◽  
Scalable Database

ABSTRACT Human leishmaniases are widespread diseases with different clinical forms caused by about 20 species within the Leishmania genus. Leishmania species identification is relevant for therapeutic management and prognosis, especially for cutaneous and mucocutaneous forms. Several methods are available to identify Leishmania species from culture, but they have not been standardized for the majority of the currently described species, with the exception of multilocus enzyme electrophoresis. Moreover, these techniques are expensive, time-consuming, and not available in all laboratories. Within the last decade, mass spectrometry (MS) has been adapted for the identification of microorganisms, including Leishmania . However, no commercial reference mass-spectral database is available. In this study, a reference mass-spectral library (MSL) for Leishmania isolates, accessible through a free Web-based application (mass-spectral identification [MSI]), was constructed and tested. It includes mass-spectral data for 33 different Leishmania species, including species that infect humans, animals, and phlebotomine vectors. Four laboratories on two continents evaluated the performance of MSI using 268 samples, 231 of which were Leishmania strains. All Leishmania strains, but one, were correctly identified at least to the complex level. A risk of species misidentification within the Leishmania donovani , L. guyanensis , and L. braziliensis complexes was observed, as previously reported for other techniques. The tested application was reliable, with identification results being comparable to those obtained with reference methods but with a more favorable cost-efficiency ratio. This free online identification system relies on a scalable database and can be implemented directly in users' computers.

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