Genetic diversity of the common bacterial blight pathogen of bean, Xanthomonas axonopodis pv. phaseoli, in Iran revealed by rep-PCR and PCR–RFLP analyses

2011 ◽  
Vol 27 (10) ◽  
pp. 2371-2378 ◽  
Author(s):  
Zahra Zamani ◽  
Masoud Bahar ◽  
Marie Agnès Jacques ◽  
Mohammad Reza Lak ◽  
Alireza Akhavan
Keyword(s):  
Genetic Diversity ◽  
Bacterial Blight ◽  
Common Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Pcr Rflp ◽  
Bacterial Blight Pathogen ◽  
The Common

scholarly journals Detection and quantification of Xanthomonas axonopodis pv. phaseoli and its variant fuscans in common bean seeds

2013 ◽  
Vol 35 (4) ◽  
pp. 428-434 ◽  
Author(s):  
Norimar D'Ávila Denardin ◽  
Vanessa Andréia Agostini
Keyword(s):  
Bacterial Blight ◽  
Seed Quality ◽  
Culture Media ◽  
Common Bacterial Blight ◽  
Common Beans ◽  
Xanthomonas Axonopodis ◽  
Overnight Incubation ◽  
Efficient Detection ◽  
The Common

The common bacterial blight of common beans (CBCF), a disease caused by Xanthomonas axonopodis pv. phaseoli (Xap) and Xanthomonas axonopodis pv. phaseoli var. fuscans (Xapf), significantly reduces grain yield and seed quality. Because this bacterium is mainly disseminated through infected seeds, efficient detection of Xap and Xapf is important to assure the productivity and quality of the crop. In this study, various techniques that included different extraction techniques (two different incubation times, with and without centrifugation) and five culture media (Kado 523, GYCA, MXP, NSA, and PTSA) were tested for the detection of the seed-borne inoculum, using three different seed samples. Overnight incubation of the seeds, followed by centrifugation and incubation in Kado 523 resulted in higher extraction of Xap and Xapf. The best extraction technique was overnight incubation followed by centrifugation, and the best medium was PTSA. Among the tested culture media, PTSA provided better identification and counting of the bacterial colonies, thus allowing the quantification of the seed infection levels.

Comparison of Seed Transmission and Survival of Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans in Common Bean Seeds

2013 ◽  
Vol 14 (1) ◽  
pp. 41 ◽  
Author(s):  
Y. He ◽  
G. P. Munkvold
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Bacterial Blight ◽  
Disease Incidence ◽  
Seed Transmission ◽  
Common Bacterial Blight ◽  
Phaseolus Vulgaris L ◽  
Transmission Frequency ◽  
Xanthomonas Axonopodis ◽  
Seed Health

Xanthomonas axonopodis pv. phaseoli (Smith) Vauterin (Xap) and Xanthomonas fuscans subsp. fuscans Schaad et al. (Xff) cause indistinguishable symptoms known as common bacterial blight of bean (Phaseolus vulgaris L.). These results confirm a higher disease incidence and seed transmission frequency of Xff compared to Xap and reinforce the need for seed health tests that can differentiate the two species. Accepted for publication 21 August 2013. Published 23 September 2013.

scholarly journals Molecular Characterization of Pathogenicity Locus (PaLoc) and tcdC Genetic Diversity Among tcdA+B+ Clostridioides Difficile Clinical Isolates in Tehran, Iran

2020 ◽  
Author(s):  
Mansoor Kodori ◽  
Zohreh Ghalavand ◽  
Abbas Yadegar ◽  
Gita Eslami ◽  
Masoumeh Azimirad ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Characterization ◽  
Disease Severity ◽  
Genetic Variants ◽  
Rflp Analysis ◽  
Clostridioides Difficile ◽  
Pcr Rflp ◽  
The Common ◽  
Healthcare Associated

Abstract Background: Clostridioides difficile is the main cause of healthcare-associated diarrhea worldwide. It is proposed that certain C. difficile toxinotypes with distinct pathogenicity locus (PaLoc) variants are associated with disease severity and outcomes. Additionally, few studies have described the common C. difficile toxinotypes, and also little is known about the tcdC variants in Iranian isolates. We characterized the toxinotypes and the tcdC genotypes from a collection of Iranian clinical C. difficile tcdA+B+ isolates with known ribotypes (RTs).Methods: Fifty C. difficile isolates with known RTs and carrying the tcdA and tcdB toxin genes were analyzed. Toxinotyping was carried out based on a PCR-RFLP analysis of a 19.6 kb region encompassing the PaLoc. Genetic diversity of the tcdC gene was determined by the sequencing of the gene.Results: Of the 50 C. difficile isolates investigated, five distinct toxinotypes were recognized. Toxinotypes 0 (33/50, 66%) and V (11/50, 22%) were the most frequently found. C. difficile isolates of the toxinotype 0 mostly belonged to RT 001 (12/33, 36.4%), whereas toxinotype V consisted of RT 126 (9/11, 81.8%). The tcdC sequencing showed six variants (35/50, 70%); tcdC-sc3 (24%), tcdC-A (22%), tcdC-sc9 (18%), tcdC-B (2%), tcdC-sc14 (2%), and tcdC-sc15 (2%). The remaining isolates were wild-types (15/50, 30%) in the tcdC gene.Conclusions: The present study demonstrates that the majority of clinical tcdA+B+ isolates of C. difficile frequently harbor tcdC genetic variants. We also found that the RT 001/ toxinotype 0 and the RT 126/ toxinotype V are the most common types among Iranian isolates. Further studies are needed to investigate the putative association of various tcdC genotypes with CDI severity and its recurrence.

Mapping genetic factors affecting the reaction to Xanthomonas axonopodis pv. phaseoli in Phaseolus vulgaris L. under field conditions

Genome ◽  
2001 ◽  
Vol 44 (6) ◽  
pp. 1046-1056 ◽  
Author(s):  
B Tar'an ◽  
T E Michaels ◽  
K P Pauls
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Length Polymorphism ◽  
Bacterial Blight ◽  
Genetic Factors ◽  
Fragment Length Polymorphism ◽  
Segregation Ratio ◽  
Common Bacterial Blight ◽  
Phaseolus Vulgaris L ◽  
Xanthomonas Axonopodis

The objectives of the present study were to evaluate the field effects of Xanthomonas axonopodis pv. phaseoli (Xap), which causes common bacterial blight (CBB) on common bean (Phaseolus vulgaris L.), and to identify genetic factors for resistance to CBB using a linkage map constructed with random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), simple sequence repeat (SSR), and amplified fragment length polymorphism (AFLP) markers. One hundred and forty-two F2:4 lines, derived from a cross between 'OAC Seaforth' and 'OAC 95-4', and the parents were evaluated for their field reaction to CBB. In the inoculated plots, the reaction to CBB was negatively correlated with seed yield, days to maturity, plant height, hypocotyl diameter, pods per plant, and harvest index. A reduction in seed yield and its components was observed when disease-free and CBB-inoculated plots were compared. The broad-sense heritability estimate of the reaction to CBB was 0.74. The disease segregation ratio was not significantly different from the expected segregation ratio for a single locus in an F2 generation. The major gene for CBB resistance was localized on linkage group (LG) G5. A simple interval mapping procedure identified three genomic regions associated with the reaction to CBB. One quantitative trait loci (QTL), each on LG G2 (BNG71DraI), G3 (BNG21EcoRV), and G5 (PHVPVPK-1) explained 36.3%, 10.2%, and 42.2% of the phenotypic variation for the reaction to CBB, respectively. Together, these loci explained 68.4% of the phenotypic variation. The relative positions of these QTL on the core common bean map and their comparison with the previous QTL for CBB resistance are discussed.Key words: common bean, molecular markers, common bacterial blight.

AFLP assessment of genetic variability in cassava accessions (Manihot esculenta) resistant and susceptible to the cassava bacterial blight (CBB)

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Gilda Sanchez ◽  
Silvia Restrepo ◽  
Myriam-Cristina Duque ◽  
Martin Fregene ◽  
Merideth Bonierbale ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Bacterial Blight ◽  
Multiple Correspondence Analysis ◽  
Aflp Analysis ◽  
Resistance Screening ◽  
Base Resistance ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Cassava Varieties

Cassava bacterial blight (CBB) is caused by Xanthomonas axonopodis pv. manihotis (Xam). Resistance is found in Manihot esculenta and, in addition, has been introgressed from a wild relative, M. glaziovii. The resistance is thought to be polygenic and additively inherited. Ninety-three varieties of M. esculenta (Crantz) were assessed by AFLPs for genetic diversity and for resistance to CBB. AFLP analysis was performed using two primer combinations and a 79.2% level of polymorphism was found. The phenogram obtained showed between 74% and 96% genetic similarity among all cassava accessions analysed. The analysis permitted the unique identification of each individual. Two Xam strains were used for resistance screening. Variation in the reaction of cassava varieties to Xam strains was observed for all plant accessions. The correlation of resistance to both strains, had a coefficient of 0.53, suggesting the independence of resistance to each strain. Multiple correspondence analysis showed a random distribution of the resistance/susceptibility response with respect to overall genetic diversity as measured by AFLP analysis. A total heterozygosity index was calculated to determine the diversity within clusters as well as among them. Our results demonstrate that resistance to CBB is broadly distributed in cassava germplasm and that AFLP analysis is an effective and efficient means of providing quantitative estimates of genetic similarities among cassava accessions.Key words: amplified fragment length polymorphism, genetic base, resistance screening, Xanthomonas axonopodis pv. manihotis.

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