Vegetative compatibility and genetic diversity in the Aspergillus flavus population of a single field

1991 ◽  
Vol 69 (8) ◽  
pp. 1707-1711 ◽  
Author(s):  
Paul Bayman ◽  
Peter J. Cotty
Keyword(s):  
Aspergillus Flavus ◽  
Soil Samples ◽  
Vegetative Compatibility ◽  
Cotton Field ◽  
Test Field ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Single Field ◽  
Key Words Aspergillus

Aspergillus flavus was isolated from soil from a single Arizona cotton field in 1987, 1988, and 1989. Isolates from infected cotton bolls were collected from the same field in 1988. Isolates were assigned to vegetative compatibility groups via complementation tests between nitrate-nonutilizing mutants. Sixty-one of 105 isolates composed 13 vegetative compatibility groups; the remaining 44 isolates could not be assigned to groups. Forty-three isolates from other fields in Arizona composed 21 groups, 6 of which were also found in the test field. Distribution of vegetative compatibility groups in and outside the field was significantly different, based on a G-test. One vegetative compatibility group included 20% of all isolates from the test field, but was not found elsewhere. It was common in the test field in 1987 and 1988, but was not found in 1989. Boll and soil populations from 1988 were not significantly different. Single infected boll locules and 25-g soil samples often contained A. flavus individuals from more than one group. These results suggest that although many vegetative compatibility groups are widely distributed, a single field may have a unique population profile that changes significantly from year to year. Key words: Aspergillus flavus, vegetative compatibility, Nit−, imperfect fungi.

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.

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 Genetic Analysis of the Aspergillus flavus Vegetative Compatibility Group to Which a Biological Control Agent That Limits Aflatoxin Contamination in U.S. Crops Belongs

2015 ◽  
Vol 81 (17) ◽  
pp. 5889-5899 ◽  
Author(s):  
Lisa C. Grubisha ◽  
Peter J. Cotty
Keyword(s):  
Aspergillus Flavus ◽  
Mating Type ◽  
Biological Control Agent ◽  
Aflatoxin Contamination ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Time And Space ◽  
Type Locus ◽  
Content Type ◽  
Compatibility Group

ABSTRACTSome filamentous fungi inAspergillussectionFlaviproduce carcinogenic secondary compounds called aflatoxins. Aflatoxin contamination is routinely managed in commercial agriculture with strains ofAspergillus flavusthat do not produce aflatoxins. These non-aflatoxin-producing strains competitively exclude aflatoxin producers and reshape fungal communities so that strains with the aflatoxin-producing phenotype are less frequent. This study evaluated the genetic variation within naturally occurring atoxigenicA. flavusstrains from the endemic vegetative compatibility group (VCG) YV36. AF36 is a strain of VCG YV36 and was the first fungus used in agriculture for aflatoxin management. Genetic analyses based on mating-type loci, 21 microsatellite loci, and a single nucleotide polymorphism (SNP) in theaflCgene were applied to a set of 237 YV36 isolates collected from 1990 through 2005 from desert legumes and untreated fields and from fields previously treated with AF36 across the southern United States. One haplotype dominated across time and space. No recombination with strains belonging to VCGs other than YV36 was detected. All YV36 isolates carried the SNP inaflCthat prevents aflatoxin biosynthesis and themat1-2idiomorph at the mating-type locus. These results suggest that VCG YV36 has a clonal population structure maintained across both time and space. These results demonstrate the genetic stability of atoxigenic strains belonging to a broadly distributed endemic VCG in both untreated populations and populations where the short-term frequency of VCG YV36 has increased due to applications of a strain used to competitively exclude aflatoxin producers. This work supports the hypothesis that strains of this VCG are not involved in routine genetic exchange with aflatoxin-producing strains.

Sign in / Sign up

Export Citation Format

Share Document