scholarly journals The potential global geographical distribution of Citrus Black Spot caused by Guignardia citricarpa (Kiely): likelihood of disease establishment in the European Union

2005 ◽  
Vol 24 (4) ◽  
pp. 297-308 ◽  
Author(s):  
Ida Paul ◽  
A.S. van Jaarsveld ◽  
L. Korsten ◽  
V. Hattingh
Keyword(s):  
European Union ◽  
Geographical Distribution ◽  
Black Spot ◽  
The European Union ◽  
Guignardia Citricarpa ◽  
Citrus Black Spot

scholarly journals Nonpathogenic Isolates of the Citrus Black Spot Fungus, Guignardia citricarpa, Identified as a Cosmopolitan Endophyte of Woody Plants, G. mangiferae (Phyllosticta capitalensis)

2002 ◽  
Vol 92 (5) ◽  
pp. 464-477 ◽  
Author(s):  
R. P. Baayen ◽  
P. J. M. Bonants ◽  
G. Verkley ◽  
G. C. Carroll ◽  
H. A. van der Aa ◽  
...  
Keyword(s):  
United States ◽  
European Union ◽  
Woody Plants ◽  
Black Spot ◽  
The United States ◽  
The European Union ◽  
Citrus Fruits ◽  
Citrus Black Spot ◽  
Group I ◽  
Group Ii

The population structure of Guignardia citricarpa sensu lato (anamorph: Phyllosticta citricarpa), a fungus of which strains pathogenic to citrus are subject to phytosanitary legislation in the European Union and the United States, was investigated. Internal transcribed spacer sequences revealed two phylogenetically distinct groups in G. citricarpa. This distinction was supported by amplified fragment length polymorphism analysis that also supported the exclusion of two isolates that had apparently been misclassified as G. citricarpa. On cherry decoction agar, but not on other media, growth rates of group I isolates were lower than those of group II isolates. Conidial dimensions were similar, but group I isolates formed conidia with barely visible mucoid sheaths, whereas those of group II formed conidia with thick sheaths. Cultures of isolates belonging to group I produced rare infertile perithecia, whereas fertile perithecia were formed by most isolates of group II. Colonies of isolates belonging to group I were less dark than those of group II, with a wider translucent outer zone and a lobate rather than entire margin. On oatmeal agar, exclusively group I isolates formed a yellow pigment. Group I harbored strains from citrus fruits with classical black spot lesions (1 to 10 mm in diameter) usually containing pycnidia. Group II harbored endophytic strains from a wide range of host species, as well as strains from symptomless citrus fruits or fruits with minute spots (<2-mm diameter) without pycnidia. These observations support the historic distinction between slowly growing pathogenic isolates and morphologically similar fast-growing, nonpathogenic isolates of G. citricarpa. The latter proved to belong to G. mangiferae (P. capitalensis), a ubiquitous endophyte of woody plants with numerous probable synonyms including G. endophyllicola, G. psidii, P. anacardiacearum, and P. theacearum. G. mangiferae occurs in the European Union and the United States on many host species including citrus, and does not cause symptoms of citrus black spot, justifying its exclusion from quarantine measures.

scholarly journals A One-Day Sensitive Method to Detect and Distinguish Between the Citrus Black Spot Pathogen Guignardia citricarpa and the Endophyte Guignardia mangiferae

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 97-101 ◽  
Author(s):  
L. Meyer ◽  
G. M. Sanders ◽  
R. Jacobs ◽  
L. Korsten
Keyword(s):  
South African ◽  
Sequence Data ◽  
Black Spot ◽  
The United States ◽  
Guignardia Citricarpa ◽  
Competitive Edge ◽  
Citrus Black Spot ◽  
Species Specific ◽  
Time Required ◽  
Slow Growing

If South African citrus exporters wish to retain their competitive edge in the European market and access new markets such as the United States of America, it is of quarantine importance to distinguish between the citrus black spot pathogen, Guignardia citricarpa, and the harmless endophyte, G. mangiferae. The endophyte is not a sanitary or phytosanitary concern. This paper describes the design of species-specific primers that are able to detect and distinguish between these two Guignardia species. Application of the primer set CITRIC1 and CAMEL2 in conjunction with the ITS4 primer yielded polymerase chain reaction (PCR) amplicons of approximately 580 bp and 430 bp for G. citricarpa and G. mangiferae, respectively. Results obtained with these primers are in accordance with sequence data, and repeated tests verified accuracy and sensitivity. A BLAST search revealed no matches other than G. citricarpa and G. mangiferae, and no positive PCR results were obtained with Colletotrichum gloeosporioides, which is the most common contaminant in black spot lesions. We are, therefore, able to distinguish G. citricarpa and G. mangiferae unequivocally using a PCR-based method. This method was further improved to directly isolate DNA from fruit lesions by means of the DNeasy Plant Mini Kit (Qiagen). This eliminates the prior need for culturing the slow-growing organism, thereby shortening the time required to one day to test for and verify the presence or absence of the pathogenic G. citricarpa in export consignments.

scholarly journals Zmiany potencjału korporacji informatycznych w Unii Europejskiej w latach 2004–2008

2010 ◽  
Vol 6 ◽  
pp. 49-66
Author(s):  
Wioletta Kilar
Keyword(s):  
European Union ◽  
Geographical Distribution ◽  
Market Value ◽  
Economic Potential ◽  
The European Union ◽  
Member States ◽  
Eu Member States ◽  
Business Operations

The article presents a study of major IT corporations whose management authorities are based in EU member states. Its objective is to identify changes in the economic potential of the corporations in years 2004–2008 as well as factors which determine geographical distribution of IT corporations within the European Union. In order to prove the thesis and the objective, the following determining features have been used: changes in the potential of IT companies (number of companies, as well as the value of assets and market value), scope of company business operations (sales value), effectiveness of their operations (financial profit/loss figure) as well as correspondence between the type of operations and the performance of relevant corporations.

scholarly journals Speciesspecific PCR primers for Guignardia citricarpa and Guignardia mangiferae

2006 ◽  
Vol 59 ◽  
pp. 141-145 ◽  
Author(s):  
K.R. Everett ◽  
J. Rees-George
Keyword(s):  
New Zealand ◽  
Venturia Inaequalis ◽  
Black Spot ◽  
Pathogenic Fungi ◽  
Pcr Primers ◽  
Colletotrichum Acutatum ◽  
Botryosphaeria Dothidea ◽  
Guignardia Citricarpa ◽  
Citrus Black Spot ◽  
Polymerase Chain

The plant pathogen Guignardia citricarpa causes citrus black spot and is not considered to be present in New Zealand Speciesspecific polymerase chain reaction (PCR) primers were designed to identify G citricarpa and G mangiferae a closely related saprotroph that is present in New Zealand These PCR primers were tested against a range of other saprotrophic and pathogenic fungi viz Botrytis cinerea Botryosphaeria dothidea B parva Cladosporium sp Colletotrichum acutatum C gloeosporioides Cryptosporiopsis sp Epicoccum sp Nigrospora sp Penicillium sp Pestalotia sp Phialophora sp Phlyctema sp Phoma sp Phomopsis sp Stemphylium sp and Venturia inaequalis The primers JRGGc were specific to G citricarpa and JRGGm to G mangiferae A 226 bp product was amplified from G mangiferae DNA using JRGGm primers and a 501 bp product was amplified from G citricarpa DNA using JRGGc primers These primers thus distinguished G citricarpa from G mangiferae and can be used to rapidly identify incursions by citrus black spot

Guignardia citricarpa. [Descriptions of Fungi and Bacteria].

1966 ◽  
Author(s):  
B. C. Sutton
Keyword(s):  
Geographical Distribution ◽  
Citrus Fruit ◽  
Black Spot ◽  
Minor Role ◽  
Latent Infections ◽  
Green Ring ◽  
Guignardia Citricarpa ◽  
Fiji Islands ◽  
Citrus Leaves ◽  
A Minor

Abstract A description is provided for Guignardia citricarpa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Citrus spp. Also recorded in a non-pathogenic form on many other hosts in the following families: Anacardiaceae, Aquifoliaceae, Bignoniaceae, Burseraceae, Cunoniaceae, Dioscoreaceae, Gramineae, Lauraceae, Leguminosae, Liliaceae, Lythraceae, Magnoliaceae, Myrtaceae, Orchidaceae, Passifloraceae, Proteaceae, Rosaceae, Rutaceae, Solanaceae, Sterculiaceae, Theaceae (29: 208; 43: 1922a; Herb. IMI). DISEASE: Black spot of citrus. Kiely (1949) described 3 types of fruit lesion: Hard spot and shot-hole spot numerous, at first circular, brown with slight depressions, later more depressed in the centre which turns grey-white, margin black and surrounded by a ring of green rind tissue; Freckle spot develops after hard spot phase with abundant lesions, small, deep organge to brick red, finally brown, lacking a green ring, Virulent spot, irregular, confluent, rapidly spreading, black in the centre where pycnidia are produced, brown nearer the edge, finally brick red at the periphery forming the margin of the sunken lesion. McOnie found field temperatures affected symptom expression (44: 1556b). Also occurs on leaves, twigs and flowers of citrus and other hosts, often as latent infections. GEOGRAPHICAL DISTRIBUTION: Widely distributed on a large number of hosts. Countries where the fungus has been reported as a pathogen of citrus fruit in the field are designated below with an asterisk: Africa (? Egypt, Kenya, Mozambique, Nigeria, *Rhodesia, *South Africa, Uganda), Asia (Ceylon, *China, *Formosa (Taiwan), Hong Kong,? India, *Indonesia, Iran, Israel, *Japan, Korea,? Malaya, Okinawa,? Pakistan,? Philippines,? Singapore,? Thailand,? Vietnam); Australasia & Oceania, (*Australia,? Fiji Islands,? Hawaii, New Hebrides), Europe (Sicily, Spain, U.S.S.R. (Republic of Georgia)); North America (United States (Florida)); Central America and the Caribbean (Honduras, Jamaica, Trinidad); South America (*Argentine, *Brazil, *Peru, Venezuela). (CMI Map 53, ed. 3, 1961; 29: 208; 44, 701; Herb. IMI). TRANSMISSION: By air-borne ascospores from perithecia produced on cirrus leaf litter (43, 1922b). Conidia produced from pycnidia require water droplets for emergence and dispersal. They play a minor role by contributing to the infection of low hanging fruit. Mycelium in latent infections of citrus leaves remains viable up to 18 days and may be detected when the leaves are incubated at 30°C (Kiely, 1949). Nursery trees may also carry latent infection into other citrus growing areas (Kiely, 1949; Wager, 1953). Wounds on fruit made by insects may also provide infection courts (16: 247, 22: 19).

scholarly journals Application of Azoxystrobin for Control of Benomyl-Resistant Guignardia citricarpa on ‘Valencia’ Oranges in South Africa

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 784-788 ◽  
Author(s):  
G. C. Schutte ◽  
R. I. Mansfield ◽  
H. Smith ◽  
K. V. Beeton
Keyword(s):  
South Africa ◽  
Disease Control ◽  
Untreated Control ◽  
Black Spot ◽  
Mineral Oil ◽  
Guignardia Citricarpa ◽  
Citrus Black Spot ◽  
Oil In Water ◽  
Small Plot

Azoxystrobin was evaluated in replicated small-plot trials from 1995 to 1999 for control of citrus black spot (CBS) on ‘Valencia’ oranges caused by Guignardia citricarpa. Applications of different rates of tank mixes of azoxystrobin and mancozeb during the susceptible period from October to January were compared with an untreated control as well as the standard four applications of mancozeb with or without mineral oil (1.20 g a.i./liter + 0.5% [vol/vol]/liter and 1.60 g a.i./liter of water, respectively). Two applications of azoxystrobin in tank mixtures with mancozeb and mineral oil (0.5% [vol/vol]/liter) in mid-November and mid-January at rates of 0.10, 0.15, and 0.20 g a.i./liter controlled CBS by more than 98 to 99%, 99 to 100% and 95 to 98%, respectively. Concomitantly, where mineral oil was not added to the fungicide mixture, azoxystrobin and mancozeb resulted only in 73 to 95%, 74 to 93% and 92.2 to 92.3% CBS control, respectively. Tank mixtures of benomyl, mancozeb, and mineral oil reduced CBS by only 29%, which could be attributed to the presence of benomyl-resistant pathogen isolates in the experimental orchard. Azoxystrobin applied at rates of 0.05, 0.075, and 0.10 g a.i./liter in tank mixtures with mancozeb (1.2 g a.i./liter) and mineral oil (0.5% [vol/vol]/liter of water) or Agral 90 (0.5% [vol/vol]/liter of water) were equally effective, reducing CBS by more than 99%. When mineral oil was compared to different adjuvants in tank mixtures with azoxystrobin and mancozeb, only mineral oil resulted in 100% clean exportable fruit. There was no difference between Sunspray 6E and Bac oil when mixed with azoxystrobin and mancozeb on the degree of disease control. Furthermore, the concentration of mineral oil in water can be lowered from 0.5% (vol/vol)/liter of water to 0.3% (vol/vol)/liter of water without a loss in efficacy against CBS. It is therefore, recommended that azoxystrobin (0.075 g a.i./liter) must be applied in tank mixtures with mancozeb (1.2 g a.i./liter) and mineral oil, which can be applied at either 0.5% (vol/vol)/liter of water or 0.3% (vol/vol)/liter of water.

scholarly journals Health literacy policies and activities: developments in the past five years

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
J Rademakers
Keyword(s):  
European Union ◽  
Health Literacy ◽  
Geographical Distribution ◽  
Policy Agenda ◽  
The European Union ◽  
European Policy ◽  
Descriptive Data ◽  
Rigorous Evaluation ◽  
The Past ◽  
Synthesis Report

Abstract Background In the past five years, two inventory studies have been performed in which health literacy policies throughout Europe were described and analyzed: the ‘Study on sound evidence for a better understanding of health literacy in the European Union’(HEALIT4EU, 2015) and the recent HEN-synthesis report on the evidence on existing policies and linked activities and their effectiveness for improving health literacy (2018). In this presentation, data from these two studies will be compared to identify current developments regarding health literacy policy. Methods The descriptive data of both studies were, amongst others, compared with respect to the number of countries with policies or activities regarding health literacy, the geographical distribution over Europe, the content of the policies and level of implementation. Results More countries have developed policies and activities in the domain of health literacy, or are currently in the process of doing so. However, gaps remain in the geographical distribution of policy, and evidence on the effectiveness of policies and activities is still marginal. Conclusions Health literacy is more prominent on the European policy agenda. Rigorous evaluation is needed to demonstrate possible benefits of the policies for individuals, communities and society as a whole.

scholarly journals High molecular diversity of the fungus Guignardia citricarpa and Guignardia mangiferae and new primers for the diagnosis of the citrus black spot

2009 ◽  
Vol 52 (5) ◽  
pp. 1063-1073 ◽  
Author(s):  
Danyelle Stringari ◽  
Chirlei Glienke ◽  
Daniel de Christo ◽  
Walter Maccheroni Jr. ◽  
João Lucio de Azevedo
Keyword(s):  
Rapd Markers ◽  
Geographical Origin ◽  
Black Spot ◽  
Polymerase Chain Reaction Analysis ◽  
Causal Agent ◽  
Specific Primers ◽  
Guignardia Citricarpa ◽  
Citrus Black Spot ◽  
Polymerase Chain ◽  
Sequence Characterized Amplified Regions

RAPD markers were used to investigate the distribution of genetic variability among a group of Guignardia citricarpa, G. mangiferae, and Phyllosticta spinarum isolates obtained from several hosts in Brazil, Argentina, Mexico, Costa Rica, Thailand, Japan, United States and South Africa. Pathogenic isolates G. citricarpa Kiely (anamorph form P. citricarpa McAlp Van Der Aa) are the etiological agent of the Citrus Black Spot (CBS), a disease that affects several citric plants and causes substantial injuries to the appearance of their fruits, thus preventing their export. Several previous studies have demonstrated the existence of an endophytic species with high morphological similarity to the causal agent of CBS that could remain latent in the same hosts. Consequently, the identification of the plants and fruits free from the causal agent of the disease is severely hampered. The RAPD analysis showed a clear discrimination among the pathogenic isolates of G. citricarpa and endophytic isolates (G. mangiferae and P. spinarum). In addition, a Principal Coordinate Analysis (PCO) based on a matrix of genetic similarity estimated by the RAPD markers showed four clusters, irrespective of their host or geographical origin. An Analysis of Molecular Variance (AMOVA) indicated that 62.8% of the genetic variation was found between the populations (G. citricarpa, G. mangiferae, P. spinarum and Phyllosticta sp.). Substantial variation was found in the populations (37.2%). Exclusive RAPD markers of isolates of G. citricarpa were cloned, sequenced and used to obtain SCARS (Sequence Characterized Amplified Regions), which allowed the development of new specific primers for the identification of G. citricarpa PCR (Polymerase Chain Reaction) analysis using a pair of primers specific to pathogenic isolates corroborating the groupings obtained by the RAPD markers, underscoring its efficiency in the identification of the causal agent of CBS.

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