scholarly journals Sexual Recombination in Gibberella zeae

1999 ◽  
Vol 89 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Robert L. Bowden ◽  
John F. Leslie
Keyword(s):  
The United States ◽  
Vegetative Compatibility ◽  
Gibberella Zeae ◽  
Rapid Testing ◽  
Wild Type ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
Sexual Recombination ◽  
Group 2 ◽  
Group 1

We developed a method for inducing sexual outcrosses in the homothallic Ascomycete fungus Gibberella zeae (anamorph: Fusarium graminearum). Strains were marked with different nitrate nonutilizing (nit) mutations, and vegetative compatibility groups served as additional markers in some crosses. Strains with complementary nit mutations were cocultured on carrot agar plates. Ascospores from individual perithecia were plated on a minimal medium (MM) containing nitrate as the sole nitrogen source. Crosses between different nit mutants segregated in expected ratios (3:1 nit-:nit+) from heterozygous perithecia. Analysis of vegetative compatibility groups of progeny of two crosses indicated two and three vegetative incompatibility (vic) genes segregating, respectively. For rapid testing of sexual recombination between nit mutants, perithecia were inverted over MM to deposit actively discharged ascospores. Development of proto-trophic wild-type colonies was taken as evidence of sexual recombination. Strains of G. zeae group 2 from Japan, Nepal, and South Africa, and from Indiana, Kansas, and Ohio in the United States were sexually interfertile. Four group 1 strains were not interfertile among themselves or with seven group 2 strains. Attempts to cross G. zeae with representatives of F. acuminatum, F. avenaceum, F. culmorum, F. crookwellense, F. oxysporum, and three mating populations of G. fujikuroi were not successful.

scholarly journals Reassessment of Vegetative Compatibility of Sclerotinia homoeocarpa Using Nitrate-Nonutilizing Mutants

2008 ◽  
Vol 98 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Y.-K. Jo ◽  
S. W. Chang ◽  
J. Rees ◽  
G. Jung
Keyword(s):  
Minimal Medium ◽  
The United States ◽  
Vegetative Compatibility ◽  
Complete Medium ◽  
Sclerotinia Homoeocarpa ◽  
Hyphal Fusion ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
Mutant Phenotypes ◽  
First Time

Nitrate-nonutilizing (nit) mutants were recovered for the first time from 21 isolates of Sclerotinia homoeocarpa collected in the United States. Mutants were selected from shredded mycelium of each isolate when cultured on water agar medium amended with 4% (wt/vol) potassium chlorate. The mutants could be classified into three phenotypes: nit1, nit3, and NitM, based on their growth on minimal medium (Czapek solution agar) supplemented with NaNO2 or hypoxanthine. Complementary heterokaryons were observed in pairings between different phenotypes of nit mutants derived from compatible isolates, but not in self-fusions or pairings between incompatible isolates. The vigor of prototrophic growth varied with isolates and mutant phenotypes. Strong and continuous heterokaryons, as well as weak and spontaneous ones, formed depending on pairings of nit mutants. Stable heterokaryons between compatible isolates, but apoptotic reactions between incompatible isolates, were observed immediately after hyphal fusion under the epifluorescence microscope. The 21 isolates used in this study, which were previously assigned into 11 different vegetative compatibility groups (VCGs) based on the formation of a barrage zone at the contact site of paired isolates on complete medium (potato dextrose agar), were regrouped into five VCGs based on heterokaryon formation between nit mutants on minimal medium.

Vegetative compatibility within Fusarium oxysporum f.sp. niveum and its relationship to virulence, aggressiveness, and race

1990 ◽  
Vol 36 (5) ◽  
pp. 352-358 ◽  
Author(s):  
R. P. Larkin ◽  
D. L. Hopkins ◽  
F. N. Martin
Keyword(s):  
Fusarium Oxysporum ◽  
The United States ◽  
Soil Samples ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
The World ◽  
Infested Field ◽  
Race 1 ◽  
Race 2

Over 250 isolates of Fusarium oxysporum collected from infected watermelon plants and soil samples from a pathogen-infested field, as well as known isolates of F. oxysporum f. sp. niveum imported from various locations around the world, were tested for pathogenicity on watermelon and used to determine vegetative compatibility groups (VCGs) within F. oxysporum f. sp. niveum. Vegetative compatibility was assessed on the basis of heterokaryon formation among nitrate-nonutilizing mutants. Race determinations were made by screening isolates on six different watermelon cultivars of varying resistance. All isolates of F. oxysporum f. sp. niveum belonged to one of three distinct VCGs, and were incompatible with isolates that were not pathogenic on watermelon. Isolates of F. oxysporum f. sp. niveum were subdivided into two races and there was a direct relationship between VCG and race. VCG 0080 consisted of race 1 isolates from five states of the United States, Taiwan, and Australia. VCG 0081 consisted solely of race 1 isolates from Florida. VCG 0082 was comprised solely of race 2 isolates, all of which were capable of causing severe wilt on all cultivars tested. Numerous Florida isolates were compatible with race 2 isolates from Texas and demonstrated comparable virulence on all cultivars, confirming the presence of race 2 in Florida. With F. oxysporum f. sp. niveum, vegetative compatibility can be utilized as an alternative or collaborative method to distinguish pathogenic from nonpathogenic strains of F. oxysporum and to differentiate subforma specialis virulence characteristics. Key words: fusarium wilt, nit mutants, watermelon.

scholarly journals An efficient method for selecting stable tester strains of vegetative compatibility groups in Verticillium dahliae

2016 ◽  
Vol 56 (2) ◽  
pp. 163-166 ◽  
Author(s):  
Maria Rataj-Guranowska
Keyword(s):  
Verticillium Dahliae ◽  
Efficient Method ◽  
Common Knowledge ◽  
Vegetative Compatibility ◽  
Wild Type ◽  
Vegetative Compatibility Groups ◽  
Cross Reactions ◽  
Nit Mutants ◽  
Genetic Barriers ◽  
The Way

Abstract The way compatible pairs of nitrate non-utilizing mutants (nit) are selected is usually not explained and remains unclear whether these pairs are representative for an isolate or strain. In addition, tester strains of Verticillium dahliae vegetative compatibility groups (VCGs) cross-react with at least one pair of tester strains of another VCG, and although it is a common knowledge of scientists working with the fungus that reversion of nit mutants to wild type occurs far too often, this fact is rarely mentioned in papers. To overcome the above problems, a protocol was developed for the generation of large number of nit mutants from any given isolate and to ensure that compatible pairs of mutants are indeed stable and the most frequent within the putative tester mutants produced from each isolate. Thus, we provide a reproducible and objective way of selecting V. dahliae tester strains for each isolate and VCG. Although VC grouping is based on the formation of stable heterokaryons, we demonstrate in this work that cross-reactions cannot be eliminated and that strict genetic barriers between two main VCG groups are absent in V. dahliae.

scholarly journals Characterization of Pyricularia grisea in the United States Using Independent Genetic and Molecular Markers

2000 ◽  
Vol 90 (12) ◽  
pp. 1396-1404 ◽  
Author(s):  
J. C. Correll ◽  
T. L. Harp ◽  
J. C. Guerber ◽  
R. S. Zeigler ◽  
B. Liu ◽  
...  
Keyword(s):  
United States ◽  
Mating Type ◽  
Population Data ◽  
The United States ◽  
Vegetative Compatibility ◽  
Dna Fingerprint ◽  
Pyricularia Grisea ◽  
Vegetative Compatibility Groups ◽  
Large Numbers ◽  
Nit Mutants

A total of 540 isolates of Pyricularia grisea from rice in the United States were examined for vegetative compatibility, MGR586 DNA fingerprint diversity, and mating type based on hybridization with the mat1-1 and mat1-2 sexual mating type alleles. The collections contained both archived and contemporary field isolates representative of the known MGR586 lineages and races that occur throughout the United States. Complementary nitrate nonutilizing (nit) or sulfate nonutilizing (sul) mutants were used to assess vegetative compatibility in P. grisea. There was a complete correspondence between vegetative compatibility groups (VCGs), MGR586 lineage, and mating type among 527 contemporary isolates (collected between 1991 and 1997) from Arkansas, Louisiana, Missouri, Mississippi, and Texas; all isolates in MGR586 lineages A, B, C, and D belonged to VCGs US-01, US-02, US-03, and US-04, respectively. In addition, all isolates tested in VCGs US-01 and US-04 had the mat1-1 mating type allele whereas those in VCGs US-02 and US-03 had the mat1-2 allele. The strict association of independent markers during this sample period was consistent with a strictly asexual mode of reproduction. However, examination of archived isolates collected in the 1970s and 1980s and contemporary isolates revealed an incongruent relationship between the independent markers. MGR586 C and E isolates were vegetatively compatible which indicated that multiple robust MGR586 delineated lineages could be nested within certain VCGs. Although isolates in lineages C and E were vegetatively compatible, they were of opposite mating type. Several hypotheses, including recombination, could account for the incongruence between the various markers. Among the eight MGR586 lineages (A through H) that occur in the United States, all isolates in lineages A, D, E, G, and H had the mat1-1 allele, whereas isolates in lineages B, C, and F had the mat1-2 allele. Nit mutants can be recovered relatively easy from P. grisea and should allow large numbers of individuals within a population to be assessed for vegetative compatibility. VCGs may prove to be an effective multilocus marker in P. grisea. Thus, VCGs should be a useful means for characterizing genetic structure in populations of the rice blast fungus worldwide, provide a useful genetic framework to assist in interpreting molecular population data, and may provide insight into potential sexual or asexual recombination events.

scholarly journals Vegetative Compatibility Groups in Cercospora kikuchii, the Causal Agent of Cercospora Leaf Blight and Purple Seed Stain in Soybean

2005 ◽  
Vol 95 (3) ◽  
pp. 257-261 ◽  
Author(s):  
G. Cai ◽  
R. W. Schneider
Keyword(s):  
Leaf Blight ◽  
Vegetative Compatibility ◽  
The Other ◽  
Wild Type ◽  
Cercospora Kikuchii ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
Pathogenicity Tests ◽  
Soybean Plants ◽  
Soybean Leaves

Nitrogen nonutilizing (Nit) mutants were used to assess vegetative compatibility of 58 isolates of Cercospora kikuchii, 55 of which were isolated from soybean plants in Louisiana. Two isolates were vegetatively self-incompatible. Of 56 self-compatible isolates, 16 were assigned to six multimember vegetative compatibility groups (VCGs), 01 to 06, with 2 or 3 isolates in each VCG. The other 40 isolates each belonged to a distinct VCG. All six multimember VCGs contained isolates from different soy bean cultivars, and three included isolates from different locations. Only one of six multimember VCGs included isolates both from soybean leaves and seed, while the other five included isolates from only leaves or seed. The likelihood of tissue specificity or preference was discussed. All isolates and tested Nit mutants produced cercosporin on potato dextrose agar under light. Significantly different amounts of cercosporin were produced among wild-type isolates, and two Nit mutants produced significantly more cercosporin than their wild-type counterparts. All isolates produced typical Cercospora leaf blight symptoms on soybean plants in greenhouse pathogenicity tests.

Classification of strains of Fusarium oxysporum on the basis of vegetative compatibility

1985 ◽  
Vol 63 (2) ◽  
pp. 179-183 ◽  
Author(s):  
John E. Puhalla
Keyword(s):  
Fusarium Oxysporum ◽  
Radial Growth ◽  
Minimal Medium ◽  
Evolutionary Model ◽  
Vegetative Compatibility ◽  
Wild Type ◽  
Vegetative Compatibility Groups ◽  
Heterokaryon Formation ◽  
Nit Mutants

Twenty-one strains of Fusarium oxysporum were classified on the basis of vegetative compatibility or the ability to form hetcrokaryons. Heterokaryon formation was demonstrated by pairing mutants that were unable to reduce nitrate. These "nit mutants" could be recovered without mutagen treatment from selective media containing KClO3. On Czapek's minimal medium the nit mutants had a radial growth rate like that of wild type, but their colonies were very thin. Two genetically different nit mutants were recovered in each of the 21 strains and paired in all combinations on minimal medium. Heterokaryon formation was indicated by dense growth where the two mutant colonies touched. As a result, 16 vegetative compatibility groups (VCGs) were defined such that only strains in the same VCG were vegetatively compatible. In no case was a strain assignable to more than one VCG. There was some evidence for a correlation between VCG and forma specialis. An evolutionary model to explain this correlation is proposed. Vegetative compatibility may be a fast and easy way to distinguish pathotypes of F. oxysporum.

scholarly journals Genetic Variability of Cercospora coffeicola from Organic and Conventional Coffee Plantings, Characterized by Vegetative Compatibility

2008 ◽  
Vol 98 (11) ◽  
pp. 1205-1211 ◽  
Author(s):  
R. B. Martins ◽  
L. A. Maffia ◽  
E. S. G. Mizubuti
Keyword(s):  
Genetic Variability ◽  
Production Systems ◽  
Diversity Index ◽  
Vegetative Compatibility ◽  
Cercospora Leaf Spot ◽  
Vegetative Compatibility Groups ◽  
Nit Mutants ◽  
Geographical Regions ◽  
Minas Gerais State ◽  
Cercospora Coffeicola

Cercospora leaf spot is a destructive fungal disease that has become a threat to the coffee industry in Brazil. Nevertheless, little is known about populations of its causal agent, Cercospora coffeicola. We evaluated the potential of using nitrogen-nonutilizing (nit) mutants and vegetative compatibility groups (VCGs) to characterize the genetic variability of the C. coffeicola population associated with coffee plantings in Minas Gerais state (MG), Brazil. A total of 90 monosporic isolates were obtained from samples collected according to a hierarchical sampling scheme: (i) state geographical regions (Sul, Mata, and Triângulo), and (ii) production systems (conventional and organic). Nit mutants were obtained and 28 VCGs were identified. The 10 largest VCGs included 72.31% of all isolates, whereas each of the remaining 18 VCGs included 1.54% of the isolates. Isolates of the largest VCGs were found in the three regions sampled. Based on the frequencies of VCGs at each sampled level, we estimated the Shannon diversity index, as well as its richness and evenness components. Genetic variability was high at all hierarchical levels, and a high number of VCGs was found in populations of C. coffeicola associated with both conventional and organic coffee plantings.

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.

Abstract P193: High Density Lipoprotein is Superior to Triglyceride as a Biomarker of Physiologic Stress in African Immigrants: The Africans in America Study

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Rafeal L Baker ◽  
Jean N Utumatwishima ◽  
Stephanie T Chung ◽  
Anne E Sumner
Keyword(s):  
High Density Lipoprotein ◽  
Allostatic Load ◽  
Density Lipoprotein ◽  
African Immigrants ◽  
Cardiac Risk ◽  
The United States ◽  
High Density ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

Introduction: For Africans living in the United States, the extent to which stress-induced physiologic dysfunction varies by reason for immigration is unknown. Allostatic load score (ALS) is used to assess physiologic stress. ALS has biomarkers in 3 domains: cardiovascular, metabolic and immune. However, there are many ALS equations and the number of biomarkers in each domain varies. In the cardiac domain of ALS, equations use either triglyceride (TG) or high density lipoprotein (HDL). A specific problem for African descent populations is that HDL may be superior to TG as a marker of insulin resistance and cardiac risk. Objective: Our primary goal in 95 African immigrants (71% male, age 42±10, (mean±SD), range 22-62y) was to determine if ALS varied by reason for immigration. Our secondary goal was to evaluate 4 different ALS equations to determine if there was a difference in ALS performance depending on whether HDL or TG was the included biomarker. Methods and Results: For all 4 equations, the reasons for immigration from lowest to highest ALS were: family reunification, lottery for self and immediate family, marriage, asylum, work and study (Figure 1). As the first 3 reasons for immigration promoted family unity, they were grouped together (Group 1). The Africans who came for other reasons were grouped together (Group 2). Equations 1 and 2 included HDL as a biomarker. For these equations, ALS in Group 1 vs. Group 2 were: 1.7±1.3 vs. 2.8±1.7, P <0.01 and 1.4±1.2 vs. 2.3±1.7, P <0.01 resp. Equations 3 and 4 used TG. For these two equations ALS in Group 1 vs. Group 2 were: 2.2±1.6 vs. 2.9±2.0, P =0.08 and 2.1±1.4 vs. 2.9±2.0, P =0.03 resp. In Equations 1 and 2, when HDL was replaced by TG, the significant difference in ALS between groups declined. In Equations 3 and 4, when TG was replaced by HDL, the significant difference in ALS between groups increased. Conclusions: ALS varies by reason for immigration and is easier to detect in ALS equations which use HDL rather than TG.

IMMU-25. SYNERGY BETWEEN TMZ AND INDIVIDUALIZED MULTIMODAL IMMUNOTHERAPY TO IMPROVE OS OF IDH1 WILD TYPE MGMT PROMOTOR UNMETHYLATED GBM PATIENTS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi97-vi97
Author(s):  
Stefaan Van Gool ◽  
Jennifer Makalowski ◽  
Volker Schirrmacher ◽  
Wilfried Stuecker
Keyword(s):  
Local Therapy ◽  
Extent Of Resection ◽  
Wild Type ◽  
Advanced Therapy Medicinal Product ◽  
Icd Therapy ◽  
Complementary Medicines ◽  
Relevant Effect ◽  
Advanced Therapy ◽  
Group 2 ◽  
Group 1

Abstract The prognosis of IDH1 wild type MGMT promotor unmethylated (MGMT-p-UM) GBM patients remains poor. Addition of TMZ to radiotherapy shifted the median OS from 11.8 to 12.6 months (Stupp, Lancet Oncol 2019). We retrospectively analysed the value of individualized multimodal immunotherapy (IMI) to improve OS in these patients. Adults with first event of IDH1wt GBM and documented status of MGMT-p-UM, and treated with IMI in the period June 2015 till July 2020, were selected. IMI consisted of 1/ immunogenic cell death (ICD) therapy (NDV injections + modulated electrohyperthermia), 2/ active specific immunotherapy with autologous mature dendritic cells loaded with tumor lysate or ICD therapy-induced serum-derived antigenic extracellular microvesicles and apoptotic bodies (IO-Vac® is an approved advanced therapy medicinal product since 27/05/2015), 3/ modulatory immunotherapy adapted to the patient, and 4/ complementary medicines. Twenty-eight patients (11f, 17m) had a median age of 48y (range 18-69) and a KPI of 90 (50-100). Extent of resection was complete (11), &lt; complete (9) or not documented (8). Seven patients were treated with surgery/radio(chemo)therapy and subsequent IMI (Group-1); 21 patients were treated with radiochemotherapy followed by maintenance TMZ + ICD therapy, followed by DC vaccines (Group-2). Both groups received further maintenance ICD therapy. Age, KPI and extent of resection were not different amongst both groups. PFS was not assessed because of challenges about pseudoprogression. The median OS of group-1 patients was 11m (2y OS: 0%). Surprisingly the median OS of group-2 patients was 18m with 2y OS of 17% (CI95%: +31, -15), which was significantly (Log-rank: p = 0.027) different from group-1. The data suggest that addition of IMI after local therapy on its own has no relevant effect on OS in IDH1 wild type MGMT-p-UM GBM patients, similar to maintenance TMZ. However, the combination of both TMZ + IMI significantly improves median OS.

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