Ecology of the Dutch Elm Disease Vectors Scolytus laevis and S. Scolytus

1987 ◽  
Vol 24 (3) ◽  
pp. 1095
Keyword(s):  
Dutch Elm Disease ◽  
Disease Vectors

Studies on the Fungal Pathogen of Dutch Elm Disease

1981 ◽  
Vol 39 ◽  
pp. 400-401
Author(s):  
H.M. Mazzone ◽  
G. Wray ◽  
R. Zerillo
Keyword(s):  
Fungal Pathogen ◽  
Fungal Growth ◽  
Polymyxin B ◽  
The United States ◽  
Dutch Elm Disease ◽  
Effective Control ◽  
Sabouraud Agar ◽  
Total Inhibition ◽  
Zones Of Inhibition ◽  
Control Plate

The fungal pathogen of the Dutch elm disease (DED), Ceratocystis ulmi (Buisman) C. Moreau, has eluded effective control since its introduction in the United States more than sixty years ago. Our studies on DED include establishing biological control agents against C. ulmi. In this report we describe the inhibitory action of the antibiotic polymyxin B on the causal agent of DED.In screening a number of antibiotics against C. ulmi, we observed that filter paper discs containing 300 units (U) of polymyxin B (Difco Laboratories) per disc, produced zones of inhibition to the fungus grown on potato dextrose agar or Sabouraud agar plates (100mm x 15mm), Fig. 1a. Total inhibition of fungal growth on a plate occurred when agar overlays containing fungus and antibiotic (polymyxin B sulfate, ICN Pharmaceuticals, Inc.) were poured on the underlying agar growth medium. The agar overlays consisted of the following: 4.5 ml of 0.7% agar, 0.5 ml of fungus (control plate); 4.0 ml of 0.7% agar, 0.5 ml of fungus, 0.5 ml of polymyxin B sulfate (77,700 U). Fig. 1, b and c, compares a control plate and polymyxin plate after seven days.

The Microscopy of Compatibility and Incompatibility in Ulmus

1985 ◽  
Vol 43 ◽  
pp. 504-505
Author(s):  
B. L. Redmond ◽  
Christopher F. Bob
Keyword(s):  
Dutch Elm Disease ◽  
Economic Losses ◽  
Hybrid Progeny ◽  
Ulmus Pumila ◽  
Ulmus Americana ◽  
American Elm ◽  
Asian Species ◽  
Ulmus Parvifolia ◽  
Initial Appearance ◽  
Chinese Elm

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

Fungi on leaves, branches and stems of trees and shrubs of Saint Petersburg suburban parks

2017 ◽  
Author(s):  
М.В. Сидельникова ◽  
А.В. Тобиас ◽  
Д.Ю. Власов
Keyword(s):  
Pathogenic Fungi ◽  
Dutch Elm Disease ◽  
City Center ◽  
Saint Petersburg ◽  
Xylotrophic Fungi ◽  
Fungi Infection ◽  
Mycological Examination ◽  
The Moment ◽  
Available Information ◽  
Trees And Shrubs

Проведены микологические обследования древесной и кустарниковой растительности на территории парковой зоны Санкт-Петербурга и пригородов. Сбор материала проводился в парках южных пригородов Санкт-Петербурга (Павловский парк, Екатерининский парк, Нижний сад и Верхний парк Ораниенбаума, Верхний сад и Нижний парк ГМЗ «Петергоф»). В сравнительных целях был обследован парк при Обуховской больнице в центре Санкт-Петербурга. На древесно-кустарниковых породах парковой зоны нами выявлено 230 видов грибов (микро- и макромицетов). На листьях выявлено 28 видов микромицетов, в числе которых возбудители мучнистой росы, ржавчины и пятнистостей. На ветвях и стволах древесных пород выявлено 150 видов микромицетов, среди которых есть как часто встречающиеся, так и редкие виды грибов. Большинство из них обнаруживается в анаморфной стадии. Наибольшее разнообразие и развитие микромицетов отмечено на сухих ветвях. Высокой вредоносностью характеризуются тиростромоз липы и голландская болезнь вязов. Выявлены устойчивые патогенные комплексы грибов, развитие которых приводит к заметному ухудшению состояния растений. На стволах живых и усыхающих деревьев, а также растительных остатках отмечено 52 вида макромицетов. Среди них выявлены доминирующие и редкие виды. Среди источников заражения древесных растений ксилотрофными грибами выделяются отмершие вязы, усохшие стволы которых можно наблюдать как в пригородных парках, так и в центральной части Санкт-Петербурга. Полученные данные существенно расширяют имеющиеся сведения по микобиоте парков Санкт-Петербурга. Mycological examination of tree and shrub vegetation on the territory of Saint Petersburg park zone and its suburbs was conducted. Material was collected in the parks of southern suburbs of Saint Petersburg (Pavlovsk Park, Catherine Park, Lower Garden and Upper Park in Oranienbaum, Upper Garden and Lower Park in Peterhof). For comparative purposes Park of Obukhov Hospital in Saint Petersburg city center was also examined. At the moment, 230 fungi species (micro- and macrofungi) were identified on trees and shrubs of the park zone. Among them, 28 species of microfungi, including powdery mildew, rust and blights pathogens were found on leaves. Also, 150 species of microfungi, including both common and rare fungi species, were found on branches and trunks. Most of them were found in the anamorphic stage. The greatest diversity and microfungi development were noted on dry branches. Thyrostromose of linden and Dutch elm disease are the most harmful. Stable complexes of pathogenic fungi, which development leads to clear decline of plants' condition, were identified. In addition, 52 species of macrofungi, including dominant and rare species, were observed on trunks of living and drying trees and vegetation residues. Among the sources of xylotrophic fungi infection of woody plants, dead elms are the most distinguished. Their dead trunks can be found in both suburban parks and the central part of Saint Petersburg. The presented data significantly expand available information on mycobiota Saint Petersburg parks.

Insecticidal Active Rotenoids from Plant Parts and Callus Culture of Medicago sativa L. from a Semiarid Region of India (Rajasthan)

2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra
Keyword(s):  
Medicago Sativa ◽  
Callus Culture ◽  
Point Of View ◽  
Semiarid Region ◽  
Disease Vectors ◽  
Vector Borne Diseases ◽  
Plant Parts ◽  
Resistant Varieties ◽  
Medicago Sativa L

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.

scholarly journals Does Local Adaptation Impact on the Distribution of Competing Aedes Disease Vectors?

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Kelly L. Bennett ◽  
William Owen McMillan ◽  
Jose R. Loaiza
Keyword(s):  
Local Adaptation ◽  
Resource Competition ◽  
Disease Vectors ◽  
Human Populations ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Climate Conditions ◽  
Ecological Resources ◽  
The Face ◽  
Arboviral Disease

Ae. (Stegomyia) aegypti L. and Aedes (Stegomyia) albopictus Skuse mosquitoes are major arboviral disease vectors in human populations. Interspecific competition between these species shapes their distribution and hence the incidence of disease. While Ae. albopictus is considered a superior competitor for ecological resources and displaces its contender Ae. aegypti from most environments, the latter is able to persist with Ae. albopictus under particular environmental conditions, suggesting species occurrence cannot be explained by resource competition alone. The environment is an important determinant of species displacement or coexistence, although the factors underpinning its role remain little understood. In addition, it has been found that Ae. aegypti can be adapted to the environment across a local scale. Based on data from the Neotropical country of Panama, we present the hypothesis that local adaptation to the environment is critical in determining the persistence of Ae. aegypti in the face of its direct competitor Ae. albopictus. We show that although Ae. albopictus has displaced Ae. aegypti in some areas of Panama, both species coexist across many areas, including regions where Ae. aegypti appear to be locally adapted to dry climate conditions and less vegetated environments. Based on these findings, we describe a reciprocal transplant experiment to test our hypothesis, with findings expected to provide fundamental insights into the role of environmental variation in shaping the landscape of emerging arboviral disease.

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