scholarly journals Sporulation of Fusarium oxysporum f. sp. lycopersici on Stem Surfaces of Tomato Plants and Aerial Dissemination of Inoculum

1997 ◽  
Vol 87 (7) ◽  
pp. 712-719 ◽  
Author(s):  
Talma Katan ◽  
E. Shlevin ◽  
J. Katan
Keyword(s):  
Fusarium Oxysporum ◽  
Selective Medium ◽  
Management Approach ◽  
Tomato Plants ◽  
Compatibility Group ◽  
Race 1 ◽  
Crown And Root Rot ◽  
Xylem Discoloration ◽  
Rot Disease ◽  
Disease Management Approach

Plants exhibiting symptoms of wilt and xylem discoloration typical of Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici were observed in greenhouses of cherry tomatoes at various sites in Israel. However, the lower stems of some of these plants were covered with a pink layer of macroconidia of F. oxysporum. This sign resembles the sporulating layer on stems of tomato plants infected with F. oxysporum f. sp. radicis-lycopersici, which causes the crown and root rot disease. Monoconidial isolates of F. oxysporum from diseased plants were assigned to vegetative compatibility group 0030 of F. oxysporum f. sp. lycopersici and identified as belonging to race 1 of F. oxysporum f. sp. lycopersici. The possibility of coinfection with F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. radicis-lycopersici was excluded by testing several macroconidia from each plant. Airborne propagules of F. oxysporum f. sp. lycopersici were trapped on selective medium in greenhouses in which plants with a sporulating layer had been growing. Sporulation on stems was reproduced by inoculating tomato plants with races 1 and 2 of F. oxysporum f. sp. lycopersici. This phenomenon has not been reported previously with F. oxysporum f. sp. lycopersici and might be connected to specific environmental conditions, e.g., high humidity. The sporulation of F. oxysporum f. sp. lycopersici on plant stems and the resultant aerial dissemination of macroconidia may have serious epidemiological consequences. Sanitation of the greenhouse structure, as part of a holistic disease management approach, is necessary to ensure effective disease control.

scholarly journals Origin of Race 3 of Fusarium oxysporum f. sp. lycopersici at a Single Site in California

2003 ◽  
Vol 93 (8) ◽  
pp. 1014-1022 ◽  
Author(s):  
G. Cai ◽  
L. Rosewich Gale ◽  
R. W. Schneider ◽  
H. C. Kistler ◽  
R. M. Davis ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Intergenic Spacer ◽  
Neighbor Joining ◽  
Vegetative Compatibility Group ◽  
Tomato Plants ◽  
Length Polymorphisms ◽  
Compatibility Group ◽  
Race 1 ◽  
Race 2 ◽  
Local Race

Thirty-nine isolates of Fusarium oxysporum were collected from tomato plants displaying wilt symptoms in a field in California 2 years after F. oxysporum f. sp. lycopersici race 3 was first observed at that location. These and other isolates of F. oxysporum f. sp. lycopersici were characterized by pathogenicity, race, and vegetative compatibility group (VCG). Of the 39 California isolates, 22 were in VCG 0030, 11 in VCG 0031, and six in the newly described VCG 0035. Among the isolates in VCG 0030, 13 were race 3, and nine were race 2. Of the isolates in VCG 0031, seven were race 2, one was race 1, and three were nonpathogenic to tomato. All six isolates in VCG 0035 were race 2. Restriction fragment length polymorphisms (RFLPs) and sequencing of the intergenic spacer (IGS) region of rDNA identified five IGS RFLP haplotypes, which coincided with VCGs, among 60 isolates of F. oxysporum from tomato. Five race 3 isolates from California were of the same genomic DNA RFLP haplotype as a race 2 isolate from the same location, and all 13 race 3 isolates clustered together into a subgroup in the neighbor joining tree. Collective evidence suggests that race 3 in California originated from the local race 2 population.

scholarly journals Disease Development Following Infection of Tomato and Basil Foliage by Airborne Conidia of the Soilborne Pathogens Fusarium oxysporum f. sp. radicis-lycopersici and F. oxysporum f. sp. basilici

2000 ◽  
Vol 90 (12) ◽  
pp. 1322-1329 ◽  
Author(s):  
Y. Rekah ◽  
D. Shtienberg ◽  
J. Katan
Keyword(s):  
Fusarium Oxysporum ◽  
Disease Incidence ◽  
Selective Medium ◽  
Management Program ◽  
Causal Agent ◽  
Soilborne Pathogens ◽  
Tomato Plants ◽  
Pathogen Invasion ◽  
Crown And Root Rot

Fusarium oxysporum f. sp. radicis-lycopersici, the causal agent of Fusarium crown and root rot of tomato, and F. oxysporum f. sp. basilici, the causal agent of Fusarium wilt in basil, are soilborne pathogens capable of producing conspicuous masses of macroconidia along the stem. The role of the airborne propagules in the epidemics of the disease in tomato plants was studied. In the field, airborne propagules of F. oxysporum f. sp. radicis-lycopersici were trapped with a selective medium and their prevalence was determined. Plants grown in both covered and uncovered pots, detached from the field soil, and exposed to natural aerial inoculum developed typical symptoms (82 to 87% diseased plants). The distribution of inoculum in the growth medium in the pots also indicated the occurrence of foliage infection. In greenhouse, foliage and root inoculations were carried out with both tomato and basil and their respective pathogens. Temperature and duration of high relative humidity affected rate of colonization of tomato, but not of basil, by the respective pathogens. Disease incidence in foliage-inoculated plants reached 75 to 100%. In these plants, downward movement of the pathogens from the foliage to the crown and roots was observed. Wounding enhanced pathogen invasion and establishment in the foliage-inoculated plants. The sporulation of the two pathogens on stems, aerial dissemination, and foliage infection raise the need for foliage protection in addition to soil disinfestation, in the framework of an integrated disease management program.

scholarly journals Vegetative Compatibility Groups of Fusarium oxysporum f. sp. lactucae from Lettuce

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 237-240 ◽  
Author(s):  
Matias Pasquali ◽  
Flavia Dematheis ◽  
Giovanna Gilardi ◽  
Maria Lodovica Gullino ◽  
Angelo Garibaldi
Keyword(s):  
Fusarium Oxysporum ◽  
Genetic Relatedness ◽  
The United States ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Race 1

Fusarium oxysporum f. sp. lactucae, the causal agent of Fusarium wilt of lettuce, has been reported in three continents in the last 10 years. Forty-seven isolates obtained from infected plants and seed in Italy, the United States, Japan, and Taiwan were evaluated for pathogenicity and vegetative compatibility. Chlorate-resistant, nitrate-nonutilizing mutants were used to determine genetic relatedness among isolates from different locations. Using the vegetative compatibility group (VCG) approach, all Italian and American isolates, type 2 Taiwanese isolates, and a Japanese race 1 were assigned to the major VCG 0300. Taiwanese isolates type 1 were assigned to VCG 0301. The hypothesis that propagules of Fusarium oxysporum f. sp. lactucae that caused epidemics on lettuce in 2001-02 in Italian fields might have spread via import and use of contaminated seeds is discussed.

Fusarium oxysporum f. sp. radicis-lycopersici. [Descriptions of Fungi and Bacteria].

1996 ◽  
Author(s):  
D. Brayford
Keyword(s):  
Fusarium Oxysporum ◽  
Geographical Distribution ◽  
Spinacia Oleracea ◽  
Solanum Melongena ◽  
Capsicum Frutescens ◽  
Tomato Plants ◽  
Arachis Hypogea ◽  
Planting Material ◽  
Fungus Gnats ◽  
Crown And Root Rot

Abstract A description is provided for Fusarium oxysporum f. sp. radicis-lycopersici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Lycopersicon spp., including L. esculentum Mill. (tomato). Plants from several families may also be susceptible to some strains, in particular Capsicum frutescens L., Solanum melongena L. (Solanaceae), Arachis hypogea L., Astragalus glycyphyllos L., Glycine max (L.) Merr., Phaseolus vulgaris L., Pisum sativum L., Trifolium spp., Vicia faba L., (Leguminosae), Cucumis spp. (Cucurbitaceae), Beta vulgaris L. and Spinacia oleracea L. (Chenopodiaceae) (Jarvis & Shoemaker, 1978; 69, 7094; 73, 7659). DISEASE: Crown and root rot. GEOGRAPHICAL DISTRIBUTION: Australia, Belgium, Canada, Crete, France, Germany, Greece, Israel, Italy, Japan, Mexico, Spain, Sweden, The Netherlands, UK, USA. TRANSMISSION: Long range dissemination is via contaminated seed (73, 5786), diseased planting material (70, 1472) and by movement of infected soil/compost (64, 2160). Locally, conidia are readily spread by water flow, e.g. in irrigation or hydroponic systems (71, 4871, 4872, 6378). Some airborne dispersal of microconidia has been detected in glasshouses (Rowe et al., 1977), presumably resulting from splash droplet formation following sporulation on nearby plant debris. Fungus gnats have been reported to transport the fungus (73, 5534).

scholarly journals Identification of a new molecular marker C2-25 linked to the Fusarium oxysporum f.sp. radicis-lycopersici resistance Frl gene in tomato

2014 ◽  
Vol 50 (No. 4) ◽  
pp. 285-287 ◽  
Author(s):  
M. Staniaszek ◽  
W. Szczechura ◽  
W. Marczewski
Keyword(s):  
Fusarium Oxysporum ◽  
Dominant Gene ◽  
Hybrid Seed Production ◽  
Caps Marker ◽  
Solanum Lycopersicum L ◽  
Breeding Programmes ◽  
Tomato Breeding ◽  
Crown And Root Rot ◽  
Rot Disease ◽  
Conserved Ortholog Set

Fusarium oxysporum Schlecht. f.sp. radicis-lycopersici Jarvis & Schoemaker (FORL) is a saprophytic fungus, responsible for the fusarium crown and root rot disease in tomato (Solanum lycopersicum L.). This is one of the most destructive pathogens of this species. A new cleaved amplified polymorphic sequence (CAPS) marker C2-25 was developed for the detection of the dominant gene Frl, which confers tomato resistance to FORL. C2-25 was amplified from a conserved ortholog set II (COSII) sequence C2_At2g38025. The XapI-derived restriction product of 700 bp was informative for the identification of FORL resistant tomato genotypes and can be used as a diagnostic marker in tomato breeding programmes and hybrid seed production.

Characterisation of Strains of Fusarium oxysporum f.sp. cubense by Production of Volatiles

1991 ◽  
Vol 39 (2) ◽  
pp. 161 ◽  
Author(s):  
NY Moore ◽  
PA Hargreaves ◽  
KG Pegg ◽  
JAG Irwin
Keyword(s):  
Fusarium Oxysporum ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Compatibility Group ◽  
Race 1 ◽  
Race 2 ◽  
Race 4

The production of volatiles on steamed rice by Australian isolates of Fusarium oxysporum f. sp. cubense correlated well with race and vegetative compatibility group (VCG). All race 4 isolates (VCGs 0120, 0129) produced distinctive volatile odours which gave characteristic gas chromatograms where the num- ber of peaks equated to VCG. Race 1 (VCGs 0124, 0125) and race 2 (VCG 0128) isolates, as well as non-pathogenic isolates of F. oxysporum from the banana rhizosphere, did not produce detectable volatiles and gave chromatograms without significant peaks.

scholarly journals Characterization of a Regional Population of Fusarium oxysporum f. sp. niveum by Race, Cross Pathogenicity, and Vegetative Compatibility

2007 ◽  
Vol 97 (4) ◽  
pp. 461-469 ◽  
Author(s):  
X. G. Zhou ◽  
K. L. Everts
Keyword(s):  
Fusarium Oxysporum ◽  
Vegetative Compatibility ◽  
Infested Soil ◽  
Vegetative Compatibility Group ◽  
Atlantic Region ◽  
Compatibility Group ◽  
Race 1 ◽  
Regional Population ◽  
Race 2

Eighty-eight isolates of Fusarium oxysporum f. sp. niveum, collected from wilted watermelon plants and infested soil in Maryland and Dela-ware, were characterized by cross pathogenicity to muskmelon, race, and vegetative compatibility. Four isolates (4.5%) were moderately pathogenic to ≥2 of 18 muskmelon cultivars in a greenhouse test, and one representative isolate also was slightly pathogenic in field microplots. The four isolates all were designated as race 2, and were in vegetative compatibility group (VCG) 0082. Of the 74 isolates to which a VCG could be assigned, 41 were in VCG 0080, the VCG distributed most widely; 27 were in VCG 0082, and were distributed in half of the 20 watermelon fields surveyed; and 6 were in the newly described VCG 0083, and were restricted to three fields. Among the isolates in VCG 0080, 8 were designated as race 0, 21 as race 1, and 12 as race 2. Of the isolates in VCG 0082, 6 were designated as race 0, 11 as race 1, and 10 as race 2. All isolates in VCG 0083 were designated as race 2. Isolates from more than one race within the same VCG or isolates from more than one VCG were recovered from single plants and fields. No differences in aggressiveness on differential watermelon cultivars were observed among isolates from different VCGs of the same race. A diverse association between virulence and VCG throughout the Mid-Atlantic region suggests that the pathotypes of F. oxysporum f. sp. niveum may be of local origin or at least long existent in the region.

scholarly journals Role of the Shrub Tamarix nilotica in Dissemination of Fusarium oxysporum f. sp. radicis-lycopersici

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 735-739 ◽  
Author(s):  
Y. Rekah ◽  
D. Shtienberg ◽  
J. Katan
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Selective Medium ◽  
Sampling Location ◽  
Susceptible Host ◽  
Growing Seasons ◽  
Tomato Field ◽  
Crown And Root Rot ◽  
Pathogen Populations

The saltcedar shrub Tamarix nilotica grows as a weed in the Arava region of Israel. This weed is commonly found in cultivated fields naturally infested with Fusarium oxysporum f. sp. radicis-lycopersici, the causal agent of tomato crown and root rot. Young bushes, 20 to 40 cm tall, were randomly uprooted from different fields. The roots were cut into segments which were placed on Fusarium-selective medium. Although the plants did not show any symptoms of disease, the roots of the shrub were colonized by the pathogen. The incidence of infected saltcedar plants and level of root colonization by F. oxysporum f. sp. radicis-lycopersici decreased with increasing distance of the sampling location from a tomato field infected with crown and root rot. F. oxysporum f. sp. radicis-lycopersici was also isolated from chaff of inflorescence samples taken from mature T. nilotica shrubs. Identity of the pathogen isolates obtained from T. nilotica roots and chaff samples was verified by pathogenicity and vegetative compatibility tests. Roots of T. nilotica plants sown under greenhouse conditions in soil naturally infested with F. oxysporum f. sp. radicis-lycopersici became colonized by the pathogen. Uprooting and removing saltcedar plants throughout the season from fields not cultivated with tomatoes lowered the inoculum density of F. oxysporum f. sp. radicis-lycopersici in the soil from 611 to 6 and from 176 to 10 CFU/g of soil in the 1998-99 and 1999-2000 growing seasons, respectively. These results demonstrate that T. nilotica may contribute to the buildup of the pathogen populations in the absence of a susceptible host. Colonization of saltcedar by F. oxysporum f. sp. radicis-lycopersici is an additional mechanism for survival of this pathogen in the fields and for dissemination through the spread of infested seed or chaff of T. nilotica.

scholarly journals Characterization of Pathogenic Races of Fusarium oxysporum f. sp. melonis Causing Fusarium Wilt of Melon in New York

Plant Disease ◽  
1997 ◽  
Vol 81 (6) ◽  
pp. 592-596 ◽  
Author(s):  
T. L. Zuniga ◽  
T. A. Zitter ◽  
T. R. Gordon ◽  
D. T. Schroeder ◽  
D. Okamoto
Keyword(s):  
New York ◽  
Fusarium Oxysporum ◽  
Nuclear Dna ◽  
New York State ◽  
Washington County ◽  
Length Polymorphisms ◽  
Close Relationship ◽  
Compatibility Group ◽  
Race 1 ◽  
Race 2

Forty-six isolates of Fusarium oxysporum f. sp. melonis obtained from soil samples throughout melon-producing areas in New York State were identified on the basis of pathogenicity and colony morphology. Physiological races 1 and 2 were identified by their reaction on a set of differential melon cultivars. Race 1 was widely distributed, occurring in six of the seven New York counties surveyed. Twenty-seven of the 28 race 1 isolates were associated with vegetative compatibility group (VCG) 0134, whereas one was incompatible with all known VCGs of F. oxysporum f. sp. melonis. Twelve out of 18 race 2 isolates were associated with VCG 0131, and occurred in four counties in eastern and western New York. Five isolates of race 2, associated with VCG 0130, were recovered from a farm in Washington County, as was a single race 2 isolate which was incompatible with all known VCGs of F. oxysporum f. sp. melonis. Restriction fragment length polymorphisms in the nuclear DNA revealed variability among the isolates examined, but race 1/VCG 0134 isolates from New York and Maryland were identical or nearly so, as were race 2/VCG 0131 isolates from the two states. These findings suggest a close relationship between the populations of F. oxysporum f. sp. melonis in New York and Maryland. Race 2 isolates were more virulent than race 1 isolates, based on the number of days to first symptoms and death of melon seedlings.

scholarly journals Genetic Diversity of Fusarium oxysporum f. sp. cubense, the Fusarium Wilt Pathogen of Banana, in Ecuador

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1133
Author(s):  
Freddy Magdama ◽  
Lorena Monserrate-Maggi ◽  
Lizette Serrano ◽  
José García Onofre ◽  
María del Mar Jiménez-Gasco
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Population Biology ◽  
Plant Protection ◽  
Control Strategies ◽  
Compatibility Group ◽  
Race 1 ◽  
Race 4 ◽  
Latin America Countries

The continued dispersal of Fusarium oxysporum f. sp. cubense Tropical race 4 (FocTR4), a quarantine soil-borne pathogen that kills banana, has placed this worldwide industry on alert and triggered enormous pressure on National Plant Protection (NPOs) agencies to limit new incursions. Accordingly, biosecurity plays an important role while long-term control strategies are developed. Aiming to strengthen the contingency response plan of Ecuador against FocTR4, a population biology study—including phylogenetics, mating type, vegetative compatibility group (VCG), and pathogenicity testing—was performed on isolates affecting local bananas, presumably associated with race 1 of F. oxysporum f. sp. cubense (Foc). Our results revealed that Foc populations in Ecuador comprise a single clonal lineage, associated with VCG0120. The lack of diversity observed in Foc populations is consistent with a single introduction event from which secondary outbreaks originated. The predominance of VCG0120, together with previous reports of its presence in Latin America countries, suggests this group as the main cause of the devastating Fusarium wilt epidemics that occurred in the 1950s associated to the demise of ‘Gros Michel’ bananas in the region. The isolates sampled from Ecuador caused disease in cultivars that are susceptible to races 1 and 2 under greenhouse experiments, although Fusarium wilt symptoms in the field were only found in ‘Gros Michel’. Isolates belonging to the same VCG0120 have historically caused disease on Cavendish cultivars in the subtropics. Overall, this study shows how Foc can be easily dispersed to other areas if restriction of contaminated materials is not well enforced. We highlight the need of major efforts on awareness and monitoring campaigns to analyze suspected cases and to contain potential first introduction events of FocTR4 in Ecuador.

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