scholarly journals Virulence not linked with vegetative compatibility groups in Australian cotton Verticillium dahliae isolates

2020 ◽  
pp. 633-640 ◽  
Author(s):  
Pearl Dadd Daigle ◽  
Karen Kirkby ◽  
Damian Collins ◽  
Will Cuddy ◽  
Peter Lonergan ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Plant Mortality ◽  
Severe Damage ◽  
Disease Symptoms ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Highly Virulent

Verticillium dahliae, the causal agent of Verticillium wilt, is a soil-borne ascomycete that infects numerous agriculturally important crops globally, including cotton. As a billion-dollar industry, cotton is economically important to Australia and the management of disease such as Verticillium wilt is key for the success of the industry. Internationally, defoliating V. dahliae isolates belonging to Vegetative Compatibility Group (VCG) 1A cause severe damage to cotton, while non-defoliating VCG2A isolates result in significantly less disease. However, in Australia, VCG2A is causing more severe damage to crops in the field than the defoliating VCG1A. This study aimed to replicate field observations in controlled greenhouse conditions. We examined and compared disease symptoms on a range of Australian commercial cotton varieties when inoculated with different V. dahliae VCGs. Seedlings were root dipped in conidial suspensions and assessed over seven weeks. The final disease score, disease over time and root length were analysed. Plant mortality resulted from both V. dahliae VCG1A and VCG2A isolates across all cotton varieties used, confirming that there are virulent VCG2A isolates present in Australia. To our knowledge, although virulent on other plant hosts, V. dahliae VCG2A has not previously been reported to be highly virulent in cotton. We infer that virulence cannot be defined solely by VCG in Australian V. dahliae isolates causing disease in cotton.

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.

scholarly journals Molecular Characterization of Vegetative Compatibility Group 4A and 4B Isolates of Verticillium dahliae Associated with Potato Early Dying

Plant Disease ◽  
2000 ◽  
Vol 84 (11) ◽  
pp. 1241-1245 ◽  
Author(s):  
K. F. Dobinson ◽  
M. A. Harrington ◽  
M. Omer ◽  
R. C. Rowe
Keyword(s):  
New York ◽  
Molecular Markers ◽  
Verticillium Dahliae ◽  
Vegetative Compatibility ◽  
Potato Seed ◽  
Potato Early Dying ◽  
Vegetative Compatibility Groups ◽  
Length Polymorphisms ◽  
Compatibility Group ◽  
Early Dying

Forty isolates of Verticillium dahliae, collected from potato seed tubers and potato plants from various regions in North America and previously assigned to vegetative compatibility groups (VCGs) 4A or 4B, were characterized using molecular markers. The VCG 4A isolates were previously shown to be a highly virulent pathotype of potato and to interact synergistically with the root-lesion nematode Pratylenchus penetrans to cause potato early dying. All but one of the VCG 4A isolates characterized in this study lacked the subspecies-specific repetitive DNA sequence E18 and could be differentiated from the remaining isolates by restriction fragment length polymorphisms (RFLPs) in the nuclear rDNA and Trp1 loci. The E18 RFLP patterns of several VCG 4B isolates from Maine and New York were highly similar to those of VCG 4B isolates previously collected from potato and tomato fields in Ontario. The data presented here suggest that the molecular markers will be useful for the detection and classification of isolates of V. dahliae associated with potato early dying.

A rose bengal amended medium for selecting nitrate-metabolism mutants from fungi

1995 ◽  
Vol 73 (4) ◽  
pp. 680-682 ◽  
Author(s):  
Karol S. Elias ◽  
Peter J. Cotty
Keyword(s):  
Rose Bengal ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Fusarium Lateritium ◽  
Compatibility Group ◽  
Nitrate Metabolism ◽  
Macroscopic Observation ◽  
The Rose ◽  
Selection Of

A rose bengal amended medium for selecting nitrate-metabolism mutants from fungi with reduced sensitivity to chlorate is described. Isolates of several species known to resist development of nitrate-metabolism mutants on chlorate medium formed such mutants when grown on the rose bengal – chlorate medium. These species include Aspergillus flavus (Link.), Fusarium lateritium (Nees ex Link.), Fusarium oxysporum (Schlecht.), Fusarium solani (Mart.) Sacc., Alternaria cassiae (Jurair and Khan), Alternaria macrospora (Zimmerman), and Alternaria tagetica (Shome and Mustafee). The medium allows selection of nitrate-metabolism mutants of certain fungal strains for which chlorate-based techniques have not been satisfactory. Resulting mutants, following phenotype determination and identification of complementary testers, can be paired to enable macroscopic observation of heterokaryon formation during vegetative compatibility analyses. Thus, this medium may facilitate development of information on delimitation of vegetative compatibility groups among strains within these taxa. Key words: chlorate resistance, population structure, vegetative compatibility group, VCG.

Further investigations of vegetative compatibility within Fusarium oxysporum f.sp. melonis

1990 ◽  
Vol 68 (6) ◽  
pp. 1245-1248 ◽  
Author(s):  
D. J. Jacobson ◽  
T. R. Gordon
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Fusarium Oxysporum ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Culture Collections ◽  
Vegetative Compatibility Groups ◽  
The Third ◽  
Geographic Origins ◽  
Compatibility Group

One hundred and nineteen strains of Fusarium oxysporum f.sp. melonis were characterized by virulence and vegetative compatibility. One hundred and seven strains were placed in four previously reported vegetative compatibility groups: 0130, 0131, 0133, and 0134. Four strains were placed in three new vegetative compatibility groups, and the remaining eight strains were vegetatively self-incompatible. Two of the three new vegetative compatibility groups shared similar geographic origins and distribution with two previously reported vegetative compatibility groups; the third represented a more isolated infestation. All vegetatively self-incompatible isolates originated from culture collections; none have been recently isolated from nature. These newly characterized strains extend our knowledge of genetic diversity in F. oxysporum f.sp. melonis. All four F. oxysporum f.sp. melonis races exist in more than one vegetative compatibility group. European strains represent four vegetative compatibility groups, one of which is present in North America and another in the Middle East. The significance of this diversity is unknown, as are the phylogenetic relationships among strains in this forma specialis.

Vegetative compatibility groups and protein electrophoresis indicate a role for basidiospores in spread of Inonotus tomentosus in spruce forests of British Columbia

1991 ◽  
Vol 69 (8) ◽  
pp. 1756-1763 ◽  
Author(s):  
Katherine J. Lewis ◽  
Everett M. Hansen
Keyword(s):  
British Columbia ◽  
Key Words ◽  
Picea Glauca ◽  
Protein Electrophoresis ◽  
Vegetative Compatibility ◽  
Protein Profiles ◽  
Vegetative Compatibility Group ◽  
Protein Patterns ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group

The importance of spore infection in the spread of Inonotus tomentosus was assessed using vegetative compatibility and protein electrophoresis. Isolates were collected from diseased spruce (Picea glauca × engelmannii) trees from five sites. Each site had several small (two or three trees) discrete disease centres, or larger patchy centres, or both. Within each site, the vegetative compatibility group and protein profiles of isolates were examined in all combinations of paired isolates. Vegetatively compatible isolates had identical protein profiles in 74% of the comparisons. Vegetatively incompatible isolates had different protein profiles 97% of the time. Usually isolates differed by only one or two protein bands. Isolates from a discrete centre were usually vegetatively compatible with identical protein patterns. Larger patchy centres consisted of multiple vegetatively compatible groups. The number of unique vegetatively compatible groups found suggests that spores are an important course of infection. Key words: vegetative compatibility, disease centre, protein electrophoresis.

Variability in Fusarium oxysporum f.sp. cubense

1990 ◽  
Vol 68 (6) ◽  
pp. 1357-1363 ◽  
Author(s):  
R. C. Ploetz
Keyword(s):  
Fusarium Oxysporum ◽  
Population Biology ◽  
Potato Dextrose Agar ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Panama Disease ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
Compatibility Group ◽  
Time Required

A worldwide collection of 96 isolates of Fusarium oxysporum f.sp. cubense (incitant of fusarial wilt of banana or Panama disease) from 12 countries was used to assess population structure in the pathogen; isolates were diverse for vegetative compatibility (11 vegetative compatibility groups) and race-specific virulence (races 1, 2, and 4). Rates of radial growth on potato dextrose agar differed at temperatures ranging from 8–36 °C for isolates in different VCGs and races (P < 0.05). On a KClO3-amended medium used to generate nitrate-nonutilizing (nit) mutants, variability in chlorate (a toxic analog of nitrate) sensitivity and the time required before nit mutants arose on the medium (mutability) was related primarily to vegetative compatibility group. In addition, cultural morphology on modified Komada's medium and potato dextrose agar was related primarily to vegetative compatibility group, whereas race was not as consistently related to these traits. In studies on the population biology and diversity in F. oxysporum f.sp. cubense, vegetative compatibility was a more useful character than race. On the basis of these results, it is suggested that F. oxysporum f.sp. cubense has had diverse origins.

Genets of Typhula ishikariensis biotype A belonging to a vegetative compatibility group

1996 ◽  
Vol 74 (11) ◽  
pp. 1695-1700 ◽  
Author(s):  
Naoyuki Matsumoto ◽  
Selya Tsushima ◽  
Kazuko Uchiyama
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Snow Mold ◽  
Vegetative Compatibility Groups ◽  
Mating Patterns ◽  
Typhula Ishikariensis ◽  
Compatibility Group ◽  
Incompatibility Alleles

Vegetative compatibility groups of Typhula ishikariensis biotype A include different isolates from various localities, and the most prevalent one (super vegetative compatibility group) was studied to reveal that this super group consisted of several genets existing throughout the habitat of T. ishikariensis biotype A in Hokkaido, Japan. Random amplified polymorphic DNA and mating incompatibility alleles were studied for 10 isolates belonging to the super vegetative compatibility group from two localities 250 km distant from each other and for five isolates belonging to different groups. Seven primers, which distinguished vegetative compatibility groups, were screened out of 60 and produced a total of 55 bands. The 10 super group isolates were divided into 5 subgroups, and the five unique isolates did not cluster with each other. Protoplasts were produced from each isolate to obtain monokaryons. They were then mated with tester monokaryons derived from basidiospores of two parental isolates, one of which belonged to the super vegetative compatibility group. Mating patterns suggested that the 10 super group isolates shared common mating incompatibility alleles but this was not the case with those belonging to unique groups. The super vegetative compatibility group was found to consist of several genets with many ramets distributed throughout the habitat of T. ishikariensis biotype A in Hokkaido. These genets were regarded as sib-related dikaryons derived from basidiospores. Keywords: Typhula ishikariensis, snow mold, genet, RAPD, mating incompatibility.

Variation within and between populations of Fusarium oxysporum based on vegetative compatibility and mitochondrial DNA

1992 ◽  
Vol 70 (6) ◽  
pp. 1211-1217 ◽  
Author(s):  
T. R. Gordon ◽  
D. Okamoto
Keyword(s):  
Mitochondrial Dna ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Agricultural Field ◽  
Vegetative Compatibility Groups ◽  
Field Soils ◽  
Compatibility Group ◽  
Mitochondrial Dna Haplotype

Two hundred isolates of Fusarium oxysporum, 100 from each of two different locations, were collected from agricultural field soils in the San Joaquin Valley of California. These isolates comprised 39 different vegetative compatibility groups. Based on the frequency distribution of vegetative compatibility groups, populations of F. oxysporum at the two collection sites were different. At least one isolate from each vegetative compatibility group was examined for polymorphisms in mitochondrial DNA. A total of 41 differences in mitochondrial DNA were identified, each of which was treated as a character and scored as present or absent in each strain. There were 11 unique combinations (haplotypes) of the 41 characters. Three mitochondrial DNA haplotypes were common to both sites and the remaining eight occurred at only one of the two sites. Isolates in the same vegetative compatibility group were always associated with the same mitochondrial DNA haplotype. Many isolates in different vegetative compatibility groups also shared a common mitochondrial DNA haplotype. Fusarium oxysporum f.sp. melonis, cause of Fusarium wilt of muskmelon, was associated with the same mitochondrial DNA haplotype as eight vegetative compatibility groups of F. oxysporum that were not pathogenic to muskmelon. This result may indicate that either the pathogen was a recent derivative of nonpathogenic strains at the same location or avirulent strains have been derived from the pathogen. Key words: anastomosis, fungi, heterokaryon, Fusarium wilt.

scholarly journals PATHOGENICITY AND VIRULENCE OF COLLETOTRICHUM SPECIES ON CUCURBIT FRUIT

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 746g-747
Author(s):  
Lusike Wasilwa ◽  
Teddy E. Morelock ◽  
James C. Correll
Keyword(s):  
Geographic Origin ◽  
Vegetative Compatibility ◽  
Mature Fruit ◽  
Disease Symptoms ◽  
Torula Yeast ◽  
Compatibility Group ◽  
Race 1 ◽  
Race 2 ◽  
Weakly Virulent ◽  
Highly Virulent

Three taxa, Colletotrichum orbiculare, the unconfirmed teleomorph of C. orbiculare (Glomerella cingulata var. orbiculare), and C. magna, have been reported to cause anthracnose of cucurbits. In a previous study, virulence, vegetative compatibility, and mtDNA RFLPs have been used to examine these taxa. The three taxa can be distinguished based on mtDNA RFLPs. Under controlled greenhouse inoculation tests, only isolates of C. orbiculare (CO) from cucurbit hosts were highly virulent on cucurbit foliage; isolates of G. cingulata (GC) and C. magna (CM), and CO from cocklebur hosts were weakly virulent or avirulent. The majority of CM and GC isolates were recovered from fruit, whereas most CO isolates were recovered from foliage. A study was conducted to evaluate the pathogenicity and virulence of anthracnose isolates on cucurbit fruit. Twenty-seven isolates of the three taxa were selected based on the host and geographic origin, mtDNA RFLP haplotype, vegetative compatibility group, and race. Mature fruit from cucumber cultivars Marketer (susceptible) and H19 (resistant) and watermelon cultivars Black Diamond (susceptible) and Charleston Gray (resistant) were used. Fruit were inoculated by placing Torula yeast agar inoculum plugs (8mm in diameter) into wounds. Following inoculation, the wounds were covered with Parafilm and incubated for 8 days at 25C at 100% RH. On the third day the Parafilm was removed from the wound. Disease symptoms were evaluated by measuring lesion diameter and depth and evaluating the presence or absence of sporulation. All three anthracnose taxa are capable of infecting cucurbit fruit. CM and GC isolates were more virulent than CO isolates on cucumber. In contrast, on `Black Diamond', CO isolates were more virulent than CM and GC isolates. No significant differences in virulence were observed on `Charleston Gray'. There were no significant differences in virulence between the races of CO except on `Charleston Gray', where race 2 isolates were significantly more virulent than race 1. CO isolates from cocklebur were only weakly virulent on cucurbit fruit.

Fusarium oxysporum associated with wilt and root rot of tomato in Queensland; races and vegetative compatibility groups

1992 ◽  
Vol 32 (5) ◽  
pp. 651 ◽  
Author(s):  
MD Ramsey ◽  
RG O'Brien ◽  
KG Pegg
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Vascular Tissue ◽  
Group Analysis ◽  
Vegetative Compatibility ◽  
Crown Rot ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Pathogenicity Tests

Twenty-two isolates of Fusarium oxysporum, from Queensland's major tomato growing areas, were studied in glasshouse pathogenicity tests and assessed for vegetative compatibility. Isolates of Fusarium oxysporum f. sp. lycopersici were identified to race using pathogenicity tests with 4 differential tomato cultivars: Grosse Lisse, Scorpio, moradade and Delta Tristar. The occurrence of race 3 in the Bundaberg district in 1988 was established. In glasshouse experiments, Fusarium wilt severity was influenced by inoculum concentration (1 x 106 v. 5 x 106 conidia/ml). Pathogenic and non-pathogenic isolates were distinguished by vegetative compatibility group analysis. However, all races were in a single vegetative compatibility group and could not be differentiated using this technique. Isolates collected from discoloured vascular tissue in the lower stems of plants with severe root rot (Pythium spp. associated), were non-pathogenic to tomato, bean and pea, although some isolates caused slight damage to cucumber. These isolates were distinctly different from Fusarium oxysporum f. sp. radicis-lycopersici, the cause of root and crown rot.

Sign in / Sign up

Export Citation Format

Share Document