scholarly journals The Population of Fusarium oxysporum f. sp. lactucae in California and Arizona

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1811-1816
Author(s):  
Kelley R. Paugh ◽  
Thomas R. Gordon
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Intermediate Step ◽  
Translation Elongation ◽  
Intergenic Spacer Region ◽  
Nit Mutants ◽  
Compatibility Group ◽  
Race 1

Fusarium wilt of lettuce, caused by Fusarium oxysporum f. sp. lactucae, is now found in all major lettuce producing regions in California and Arizona. The population structure of F. oxysporum f. sp. lactucae in California and Arizona was characterized based on somatic compatibility and sequences of the translation elongation factor 1-α gene (EF-1α) and rDNA intergenic spacer region (IGS). In this study, 170 isolates were tested for somatic compatibility based on heterokaryon formation, using complementary nitrate nonutilizing (nit) mutants. Five subgroups (A to E) of somatic compatibility group 0300 were identified. Isolates associated with the same subgroup had a strong complementation reaction, whereas reactions between isolates of different subgroups were weak or delayed. An isolate from the first known infestation of Fusarium wilt of lettuce in California was associated with subgroup A, which predominated among isolates in our collection. Isolates representative of each subgroup were confirmed to be associated with race 1, based on the reaction of differential lettuce cultivars. It is possible that somatic compatibility subgroups B to E of F. oxysporum f. sp. lactucae were derived from subgroup A, as a consequence of somatic mutations affecting compatibility. If so, subgroups of F. oxysporum f. sp. lactucae may represent an intermediate step in divergence that will lead to clearly separable compatibility groups. Sequences of EF-1α and IGS were both identical for 58 isolates of F. oxysporum f. sp. lactucae that represented all somatic compatibility subgroups and locations from which isolates were obtained, indicating that subgroups were derived from the same clonal lineage (VCG 0300).

scholarly journals Fusarium oxysporumf. sp.mori, a New Forma Specialis Causing Fusarium Wilt of Blackberry

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 2066-2072 ◽  
Author(s):  
A. M. Pastrana ◽  
S. C. Kirkpatrick ◽  
M. Kong ◽  
J. C. Broome ◽  
T. R. Gordon
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Translation Elongation ◽  
Data Set ◽  
Tubulin Genes ◽  
Forma Specialis ◽  
Sequence Types ◽  
Strawberry Cultivars

Fusarium oxysporum has recently been identified as the cause of a wilt disease affecting blackberry in California and Mexico. Thirty-six isolates of F. oxysporum obtained from symptomatic blackberry plants in California and Mexico were comprised of nine distinct somatic compatibility groups (SCGs). Phylogenetic analysis of a concatenated data set, consisting of sequences of the translation elongation factor 1-α and β-tubulin genes and the intergenic spacer of the ribosomal DNA, identified nine three-locus sequence types, each of which corresponded to an SCG. Six SCGs were present only in California, two only in Mexico, and one in both California and Mexico. An isolate associated with the most common SCG in California was tested for pathogenicity on blueberry, raspberry, strawberry, and lettuce. All blueberry, raspberry, and lettuce plants that were inoculated remained healthy, but two of the five strawberry cultivars tested developed symptoms. The three strawberry cultivars that were resistant to the blackberry pathogen were also resistant to F. oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry. We propose to designate strains of F. oxysporum that are pathogenic to blackberry as Fusarium oxysporum f. sp. mori forma specialis nov.

scholarly journals Genetic Diversity of Fusarium oxysporum f. sp. cubense in East and Central Africa

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Patrick Karangwa ◽  
Diane Mostert ◽  
Privat Ndayihanzamaso ◽  
Thomas Dubois ◽  
Björn Niere ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Disease Management ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Management Practices ◽  
Management Strategies ◽  
Central Africa ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Intergenic Spacer Region

Banana Fusarium wilt is a major production constraint globally and a significant threat to the livelihoods of millions of people in East and Central Africa (ECA). A proper understanding of the diversity and population dynamics of the causal agent, Fusarium oxysporum f. sp. cubense (Foc), could be useful for the development of sustainable disease management strategies for the pathogen. The current study investigated the diversity of Foc in ECA using vegetative compatibility group (VCG) analysis, PCR-RFLPs of the ribosomal DNA’s intergenic spacer region, as well as phylogenetic analysis of the elongation factor-1α gene. Six VCGs (0124, 0125, 0128, 01212, 01220, and 01222), which all belong to one lineage (Foc lineage VI), were widely distributed throughout the region. VCGs 0128 and 01220 are reported for the first time in Burundi, the Democratic Republic of Congo (DRC), Rwanda, Tanzania, and Uganda, while VCG 01212 is reported in the DRC and Rwanda. Isolates that did not belong to any of the known VCGs were identified as Foc lineage VI members by phylogenetic analysis and may represent novel VCGs. CAV 2734, a banana pathogen collected in Rwanda, clustered with nonpathogenic F. oxysporum isolates in lineage VIII. Results from this study will contribute significantly toward the implementation of banana Fusarium wilt disease management practices in the region, such as the restricted movement of infected planting material and the selective planting of resistant banana varieties.

scholarly journals Study of Phylogenetic Relationships Among Fusarium oxysporum f. sp. dianthi Isolates: Confirmation of Intrarace Diversity and Development of a Practical Tool for Simple Population Analyses

Plant Disease ◽  
2015 ◽  
Vol 99 (6) ◽  
pp. 780-787 ◽  
Author(s):  
M. C. Cañizares ◽  
C. Gómez-Lama ◽  
M. D. García-Pedrajas ◽  
E. Pérez-Artés
Keyword(s):  
Fusarium Oxysporum ◽  
Phylogenetic Relationships ◽  
Phylogenetic Analyses ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Translation Elongation ◽  
Pathogenic Variants ◽  
Molecular Group ◽  
Compatibility Group ◽  
Practical Tool

Fusarium wilt, caused by Fusarium oxysporum f. sp. dianthi, is the most important disease of carnation worldwide. Knowing the diversity of the F. oxysporum f. sp. dianthi population present in a carnation growing area is a key component of preventing dramatic losses in production. Sequence analyses of partial β-tubulin, translation elongation factor 1α genes, and the full-length ribosomal DNA intergenic spacer (IGS) were conducted to resolve phylogenetic relationships in a wide collection of Spanish F. oxysporum f. sp. dianthi isolates, along with some representatives from Italy. We found that, among the three different gene regions, the IGS sequence was the best choice to resolve phylogenetic relationships among F. oxysporum f. sp. dianthi isolates. The phylogenetic tree generated with the complete IGS region was the only one showing a clear clustering of isolates according to the molecular group (virulence grouping) and the vegetative compatibility group. In order to develop a more practical tool based on a shorter DNA sequence to quickly analyze diversity in F. oxysporum f. sp. dianthi populations, we examined IGS nucleotide alignments and identified a region of approximately 300 bp that accumulates enough “informative” changes to resolve intraspecific relationships and determine pathogenic variants in F. oxysporum f. sp. dianthi. Moreover, the “condensed” alignment of this short IGS region showing only the informative positions revealed the existence of virulence group-discriminating positions. In addition to clarifying the phylogenetic relationships among F. oxysporum f. sp. dianthi isolates of the recently described race groups by using multigene genealogies, we have developed simple tools for the phylogenetic analyses of F. oxysporum f. sp. dianthi populations and the determination of the molecular group of uncharacterized F. oxysporum f. sp. dianthi isolates.

scholarly journals Evaluation of Nonpathogenic Fusarium oxysporum and Pseudomonas fluorescens for Panama Disease Control

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 951-959 ◽  
Author(s):  
A. Belgrove ◽  
C. Steinberg ◽  
A. Viljoen
Keyword(s):  
Fusarium Oxysporum ◽  
Pseudomonas Fluorescens ◽  
Fusarium Wilt ◽  
Intergenic Spacer ◽  
Polymorphism Analysis ◽  
Panama Disease ◽  
Intergenic Spacer Region ◽  
Soil Microbial ◽  
Fusarium Wilt Of Banana ◽  
Species Specific

Nonpathogenic Fusarium oxysporum endophytes from healthy banana roots were evaluated for their ability to reduce Fusarium wilt of banana (Panama disease). Isolates were identified morphologically and by using species-specific primers. Pathogenicity was confirmed by inoculating banana plantlets in the greenhouse. Nonpathogenic F. oxysporum isolates were grouped into 14 haplotype groups by polymerase chain reaction restriction fragment length polymorphism analysis of the intergenic spacer region, and representative isolates evaluated for biocontrol of F. oxysporum f. sp. cubense. In the greenhouse, 10 nonpathogenic F. oxysporum isolates were able to significantly reduce Fusarium wilt of banana. The isolate that protected banana plantlets best in the greenhouse, a nonpathogenic F. oxysporum from the root rhizosphere, and Pseudomonas fluorescens WCS 417 were then field tested. When the putative biological control organisms were tested in the field, neither the nonpathogenic F. oxysporum, P. fluorescens, nor combinations thereof reduced Fusarium wilt development significantly. A number of factors could contribute to the lack of field protection, including soil microbial and chemical composition and reduced survival of biocontrol organisms in banana roots. A lack of knowledge regarding the etiology of Fusarium wilt of ‘Cavendish’ banana in the subtropics and the effect of F. oxysporum f. sp. cubense race and banana cultivar in protection of banana by biocontrol organisms should be further investigated.

scholarly journals Genetic Diversity and Population Structure of Races of Fusarium oxysporum Causing Cotton Wilt

2020 ◽  
Vol 10 (9) ◽  
pp. 3261-3269
Author(s):  
Hannah C Halpern ◽  
Peng Qi ◽  
Robert C Kemerait ◽  
Marin T Brewer
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Fusarium Oxysporum ◽  
Principal Components ◽  
Phylogenetic Trees ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Pathogenic Fungi ◽  
The United States ◽  
Intergenic Spacer Region

Abstract To better understand the evolution of virulence we are interested in identifying the genetic basis of this trait in pathogenic fungi and in developing tools for the rapid characterization of variation in virulence among populations associated with epidemics. Fusarium oxysporum f. sp. vasinfectum (FOV) is a haploid fungus that causes devastating outbreaks of Fusarium wilt of cotton wherever it is grown. In the United States, six nominal races and eleven genotypes of FOV have been characterized based on the translation elongation factor (EF-1α) gene and intergenic spacer region (IGS), but it is unclear how race or genotype based on these regions relates to population structure or virulence. We used genotyping-by-sequencing to identify SNPs and determine genetic diversity and population structure among 86 diverse FOV isolates. Six individuals of Fusarium oxysporum closely related to FOV were genotyped and included in some analyses. Between 193 and 354 SNPs were identified and included in the analyses depending on the pipeline and filtering criteria used. Phylogenetic trees, minimum spanning networks (MSNs), principal components analysis (PCA), and discriminant analysis of principal components (DAPC) demonstrated that races and genotypes of FOV are generally not structured by EF-1α genotype, nor are they monophyletic groups with the exception of race 4 isolates, which are distinct. Furthermore, DAPC identified between 11 and 14 genetically distinct clusters of FOV, whereas only eight EF-1α genotypes were represented among isolates; suggesting that FOV, especially isolates within the widely distributed and common race 1 genotype, is more genetically diverse than currently recognized.

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.

scholarly journals First Report of Race 2 of Fusarium oxysporum f. sp. lycopersici, the Causal Agent of Fusarium Wilt on Tomato in Taiwan

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 111-111 ◽  
Author(s):  
Z. M. Sheu ◽  
T. C. Wang
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Banding Pattern ◽  
Vascular Tissue ◽  
First Report ◽  
Intergenic Spacer Region ◽  
Stunted Growth ◽  
Vascular Discoloration ◽  
Race 1 ◽  
Race 2

Fusarium wilt caused by Fusarium oxysporum Schlechtend.:Fr. f. sp. lycopersici (Sacc.) W.C. Snyder & N.H. Hans. is a destructive disease of tomato crops worldwide. The use of resistant varieties is the best strategy for disease control. There are three reported races of the pathogen. Recent surveys indicated that many of the commercial cultivars with resistance to F. oxysporum f. sp. lycopersici race 1 planted in Taiwan displayed Fusarium wilt symptoms. Yellowing on the older leaves was observed on one side of the stems close to fruit maturity. The yellowing gradually affected most of the foliage and was accompanied by wilting of the plants. The vascular tissue was usually dark brown and discoloration extended to the apex. The wilting became more extensive until plants collapsed and died. A total of 87 isolates obtained from typical diseased plants throughout Taiwan from 2002 to 2005 were analyzed to determine the race and distribution of this pathogen in Taiwan. Isolates were confirmed at the species level using F. oxysporum-specific primers FOF1 and FOR1 (4). Subsequently, isolates were characterized for pathogenicity, race and restriction fragment length polymorphisms of the intergenic spacer region of rDNA (IGS-RFLP) with two reference isolates, Fol 11A (race 1) and Fol 34-1 (race 2). Pathogenicity tests and race determination were conducted using root-dip inoculation (3) on 2-week-old seedlings of host differentials Bonny Best (no resistance), UC82-L (resistant to race 1), and Florida MH-1 (resistant to races 1 and 2). Thirty-six seedlings of each cultivar were arranged into three replications and inoculated with each isolate. Disease reaction was evaluated 3 weeks after inoculation. The disease severity rating (DSR) was determined on individual plants according to the following scale: 0 = plant healthy without external symptoms; 1 = slight vascular discoloration with or without stunted growth; 2 = severe vascular discoloration usually with stunted growth; and 3 = plant wilted beyond recovery or dead. The presence of severe vascular discoloration indicated a susceptible reaction. All isolates were race 2, and over 70% of the isolates showed strong virulence with a DSR >2 on cvs. Bonny Best and UC-82L. This result was different from a previous report of race 1 from Taiwan (2). Two IGS-RFLP haplotypes generated by EcoRI, RsaI, and HaeIII digestions (1) were identified. Eighty-six isolates displayed one banding pattern, and one unique isolate displayed a second banding pattern. The results demonstrated the predominance of race 2 and low diversity within the Taiwan population. To our knowledge, this is the first report regarding the predominant race and IGS-RFLP haplotype identification of F. oxysporum f. sp. lycopersici in Taiwan. Our study indicates that tomato varieties in Taiwan should possess resistance to race 2. References: (1) G. Cai et al. Phytopathology 93:1014, 2003. (2) K. S. Elias and R. W. Schneider. Phytopathology 82:1421, 1992. (3) J. W. Gerdemann and A. M. Finley. Phytopathology 41:238, 1951. (4) P. K. Mishra et al. FEMS Microbiol. Lett. 218:329, 2003.

scholarly journals Identification of Pathogenicity Groups and Pathogenic Molecular Characterization of Fusarium oxysporum f. sp. sesami in China

2020 ◽  
Vol 110 (5) ◽  
pp. 1093-1104
Author(s):  
Yinghui Duan ◽  
Wenwen Qu ◽  
Shuxian Chang ◽  
Chun Li ◽  
Fangfang Xu ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Gene Tree ◽  
Elongation Factor ◽  
Wilt Disease ◽  
Translation Elongation ◽  
Formae Speciales ◽  
Genome Data ◽  
Fusarium Wilt Disease ◽  
Six Genes

Fusarium oxysporum f. sp. sesami is an extremely destructive pathogen, causing sesame Fusarium wilt disease worldwide. To clarify the pathogenicity and the genetic characters of F. oxysporum f. sp. sesami, we systematically investigated 69 F. oxysporum isolates collected from major sesame-growing areas in China. Among these isolates, 54 isolates were pathogenic and 15 were nonpathogenic according to pathogenicity testing on sesame seedlings. For the pathogenic isolates, three F. oxysporum f. sp. sesami pathogenicity groups were defined based on the three differential sesame hosts for the first time. A translation elongation factor 1α gene tree was constructed to determine the genetic diversity of the F. oxysporum isolates but could not separate F. oxysporum f. sp. sesami isolates from the nonpathogenic isolates and other F. oxysporum formae speciales. Ten secreted-in-xylem (SIX) genes (one family of effectors) were identified in F. oxysporum f. sp. sesami isolates by a search with the genome data, and were subsequently screened in the 69 F. oxysporum isolates. Compared with the SIX gene profiles in other F. oxysporum formae speciales, the presence and sequence variations of the SIX gene homologs directly correlated with the specific pathogenicity of F. oxysporum f. sp. sesami toward sesame. Furthermore, eight of these F. oxysporum f. sp. sesami SIX genes were significantly expressed in sesame plants as infection of the F. oxysporum f. sp. sesami isolate. These findings have important significance for understanding the pathogenic basis of F. oxysporum f. sp. sesami isolates, and will contribute to improve the diagnostics to effectively control Fusarium wilt disease in sesame.

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 Genetic and Pathogenic Variability of Fusarium oxysporum f. sp. cepae Isolated from Onion and Welsh Onion in Japan

2015 ◽  
Vol 105 (4) ◽  
pp. 525-532 ◽  
Author(s):  
Kazunori Sasaki ◽  
Katsuya Nakahara ◽  
Shuhei Tanaka ◽  
Masayoshi Shigyo ◽  
Shin-ichi Ito
Keyword(s):  
Fusarium Oxysporum ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Welsh Onion ◽  
Translation Elongation ◽  
Vegetative Compatibility Groups ◽  
Fusarium Basal Rot ◽  
Pathogenicity Tests ◽  
Pathogenic Variability ◽  
Translation Elongation Factor 1Α

Fusarium oxysporum f. sp. cepae causes Fusarium basal rot in onion (common onion) and Fusarium wilt in Welsh onion. Although these diseases have been detected in various areas in Japan, knowledge about the genetic and pathogenic variability of F. oxysporum f. sp. cepae is very limited. In this study, F. oxysporum f. sp. cepae was isolated from onion and Welsh onion grown in 12 locations in Japan, and a total of 55 F. oxysporum f. sp. cepae isolates (27 from onion and 28 from Welsh onion) were characterized based on their rDNA intergenic spacer (IGS) and translation elongation factor-1α (EF-1α) nucleotide sequences, vegetative compatibility groups (VCGs), and the presence of the SIX (secreted in xylem) homologs. Phylogenetic analysis of IGS sequences showed that these isolates were grouped into eight clades (A to H), and 20 onion isolates belonging to clade H were monophyletic and assigned to the same VCG. All the IGS-clade H isolates possessed homologs of SIX3, SIX5, and SIX7. The SIX3 homolog was located on a 4 Mb-sized chromosome in the IGS-clade H isolates. Pathogenicity tests using onion seedlings showed that all the isolates with high virulence were in the IGS-clade H. These results suggest that F. oxysporum f. sp. cepae isolates belonging to the IGS-clade H are genetically and pathogenically different from those belonging to the other IGS clades.

Sign in / Sign up

Export Citation Format

Share Document