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 Comparison of Molecular Procedures for Detection and Identification of Guignardia citricarpa and G. mangiferae

Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 525-531 ◽  
Author(s):  
N. A. Peres ◽  
R. Harakava ◽  
G. C. Carroll ◽  
J. E. Adaskaveg ◽  
L. W. Timmer
Keyword(s):  
Extraction Procedure ◽  
Citrus Fruit ◽  
Black Spot ◽  
Polymerase Chain Reaction Primer ◽  
Internal Transcribed Spacer Region ◽  
Guignardia Citricarpa ◽  
Detection And Identification ◽  
Specificity And Sensitivity ◽  
Fruit Spot ◽  
Primer Sets

Citrus black spot, caused by Guignardia citricarpa, is a serious fruit spot disease and is widely distributed in Asia, southern Africa, and South America, but does not occur in North America or the Mediterranean region. A nonpathogenic species, G. mangiferae, is cosmopolitan with a wide host range and can colonize citrus fruit and leaves saprophytically. Detection and identification of Guignardia spp. on citrus fruit is necessary for epidemiological, management, and regulatory purposes. In this study, we compared published and unpublished polymerase chain reaction primer sets for their specificity and sensitivity in the detection and differentiation of the two Guignardia spp. All primers evaluated successfully identified the two species using purified DNA from fungal cultures or mycelia as source materials. However, some primer sets were not highly effective in detecting G. citricarpa when DNA was extracted directly from single characteristic black spot lesions on fruit. Thus, new primer pairs for both species were designed from the internal transcribed spacer region that were highly sensitive and specific for detection of G. citricarpa using DNA recovered from single lesions on fruit by a rapid DNA extraction procedure.

scholarly journals Chitosan reduces infection by Guignardia citricarpa in postharvest 'Valencia' oranges

2009 ◽  
Vol 52 (3) ◽  
pp. 513-521 ◽  
Author(s):  
Maria Cristina Canale Rappussi ◽  
Sérgio Florentino Pascholati ◽  
Eliane Aparecida Benato ◽  
Patrícia Cia
Keyword(s):  
Citric Acid ◽  
Biochemical Analysis ◽  
Control Measure ◽  
Citrus Fruit ◽  
Black Spot ◽  
Resistance Induction ◽  
Guignardia Citricarpa ◽  
Black Spots ◽  
Room Condition

Citrus fruits are affected by the black spot disease caused by Guignardia citricarpa. Resistance induction is an alternative control measure and chitosan exhibits potential as resistance inducer. The effect of chitosan on G. citricarpa was evaluated in vitro and in 'Valencia' oranges. Citrus fruit were immersed into different chitosan concentrations. Chitosan (2%), combined with or without thiabendazole and the citric acid was also investigated. All the chitosan concentrations inhibited G. citricarpa mycelial growth and affected morphologically the conidial germination and appressorium formation. Chitosan inhibited the development of new lesions in oranges at room condition or under refrigeration. Thiabendazole and citric acid did not reduce the formation of lesions. Biochemical analysis revealed that chitinase, β-1,3-glucanase, peroxidase and polyphenoloxidase activities were increased in chitosan-treated fruits. Thus, the effect of chitosan on the reduction of black spots in 'Valencia' oranges could be due to the germicidal effect on the pathogen and/or resistance induction in the fruit.

Effects of a trematode infestation on body condition, reproduction and mating behaviors in a livebearing fish

Behaviour ◽  
2011 ◽  
Vol 148 (8) ◽  
pp. 967-984 ◽  
Author(s):  
Raelynn Deaton ◽  
Rachel E. Martin ◽  
Stacy B. Stoops ◽  
James C. Cureton II ◽  
Richard L. Lewis
Keyword(s):  
Sexual Selection ◽  
Body Condition ◽  
Black Spot ◽  
Minor Role ◽  
Energy Reserves ◽  
Male Mate ◽  
Livebearing Fish ◽  
A Minor ◽  
Coercive Mating

AbstractMost studies of parasite-mediated sexual selection target organisms where female or male mate choice is the major driving force of sexual selection, leaving the effects of parasites on coercive mating systems understudied. Here, we investigated the role of a trematode infestation (black spot disease (BSD)) on female body condition, female fecundity, male coercion, and female resistance in a coercive livebearing fish (the western mosquitofish, Gambusia affinis). We tested the following predictions: (1) infected females are in poorer body condition and have lower fecundity than uninfected females; (2) males prefer to coerce uninfected females; (3) infected males coerce less frequently than uninfected males; and (4) infected females are less resistant to male coercion. In contrast to our first prediction, infected females had more energy reserves than uninfected females during one month and infected females had increased fecundity compared to uninfected females. In the behavior experiments, we found BSD influenced male coercion in two of our experiments supporting our third, but not second or fourth, prediction. These results suggest this parasitic infestation may play a minor role in sexual selection on G. affinis.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

scholarly journals The preendosomal compartment comprises distinct coated and noncoated endocytic vesicle populations.

1991 ◽  
Vol 113 (4) ◽  
pp. 731-741 ◽  
Author(s):  
S H Hansen ◽  
K Sandvig ◽  
B van Deurs
Keyword(s):  
Cell Surface ◽  
Coated Vesicles ◽  
Minor Role ◽  
Specific Marker ◽  
Con A ◽  
Early Endosomes ◽  
Gold Conjugate ◽  
Entire Cell ◽  
A Minor ◽  
Endocytic Vesicles

The transfer of molecules from the cell surface to the early endosomes is mediated by preendosomal vesicles. These vesicles, which have pinched off completely from the plasma membrane but not yet fused with endosomes, form the earliest compartment along the endocytic route. Using a new assay to distinguish between free and cell surface connected vesicle profiles, we have characterized the preedosomal compartment ultrastructurally. Our basic experimental setup was labeling of the entire cell surface at 4 degrees C with Con A-gold, warming of the cells to 37 degrees C to allow endocytosis, followed by replacing incubation medium with fixative, all within either 30 or 60 s. Then the fixed cells were incubated with anti-Con A-HRP to distinguish truly free (gold labeled) endocytic vesicles from surface-connected structures. Finally, analysis of thin (20-30 nm) serial sections and quantification of vesicle diameters were carried out. Based on this approach it is shown that the preendosomal compartment comprises both clathrin-coated and non-coated endocytic vesicles with approximately the same frequency but with distinct diameter distributions, the average noncoated vesicle being smaller (95 nm) than the average coated one (110 nm). In parallel experiments, using an anti-transferrin receptor gold-conjugate as a specific marker for clathrin-dependent endocytosis it is also shown that uncoating of coated vesicles plays only a minor role for the total frequency of noncoated vesicles. Furthermore, after perturbation of clathrin-dependent endocytosis by potassium depletion where uptake of transferrin is blocked, noncoated endocytic vesicles with Con A-gold, but not coated vesicles, exist already after 30 and 60 s. Finally, it is shown that the existence of small, free vesicles in the short-time experiments cannot be ascribed to recycling from the early endosomes.

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