scholarly journals Measuring the Genetic Diversity of Xanthomonas axonopodis pv. manihotis Within Different Fields in Colombia

2000 ◽  
Vol 90 (7) ◽  
pp. 683-690 ◽  
Author(s):  
S. Restrepo ◽  
C. M. Vélez ◽  
V. Verdier
Keyword(s):  
Genetic Diversity ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Dna Polymorphism ◽  
Fragment Length Polymorphism ◽  
Close Association ◽  
Aflp Data ◽  
Cassava Bacterial Blight ◽  
Xanthomonas Axonopodis ◽  
Phenetic Relationships

Cassava bacterial blight, caused by Xanthomonas axonopodis pv. manihotis, is a widespread disease that affects cassava (Manihot esculenta). We collected 238 X. axonopodis pv. manihotis strains by intensively sampling single fields in four edaphoclimatic zones (ECZs) in Colombia. DNA polymorphism of different X. axonopodis pv. manihotis populations was assessed by restriction fragment length polymorphism (RFLP) analyses, repetitive sequence-based polymerase chain reaction (rep-PCR), and amplified fragment length polymorphism (AFLP) assays. Genetic diversity, phenetic relationships among strains, and the coefficient of genetic differentiation were determined. All strains were tested for aggressiveness on the susceptible cassava cv. MCOL 1522. Strains were also tested for virulence on cassava differentials adapted to the strains' respective ECZs. Our study showed that the Colombian X. axonopodis pv. manihotis population has a high degree of genetic diversity. The hierarchical analysis of diversity showed genotypic differentiation at all levels, among ECZs, among fields within ECZs, and among strains within fields planted to several cassava genotypes. New RFLP haplotypes were detected, leading to the characterization of a new pathotype. Dendrograms from AFLP were more robust than those from RFLP data. A close association between the strains' geographical origin and DNA polymorphism was obtained using RFLP and AFLP data. We suggest that the host played a role in causing pathogen differentiation.

Intra-species DNA polymorphism in the tobacco cyst – nematode complex (Globodera tabacum) using AFLP

Genome ◽  
2001 ◽  
Vol 44 (6) ◽  
pp. 941-946
Author(s):  
Laurent Marché ◽  
Sylvie Valette ◽  
Eric Grenier ◽  
Didier Mugniéry
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Dna Polymorphism ◽  
Fragment Length Polymorphism ◽  
Cyst Nematode ◽  
Current Classification ◽  
Species Variability

Amplified fragment length polymorphism (AFLP) was used to obtain information on the within-species genetic variability of the tobacco cyst – nematode (TCN) complex. AFLP was found to be well suited to this type of study. The current classification of TCN was confirmed. Results indicate that the Globodera tabacum solanacearum group, believed to be restricted to the U.S.A., also occurs in Mexico. The within-species variability of TCN is considerable. Populations from Mexico may form a new subgroup. AFLP group-specific markers were identified for two of the TCN subgroups: Globodera tabacum tabacum and Globodera tabacum solanacearum.Key words: Heteroderinae, classification, markers, genetic diversity, geographic distribution.

scholarly journals Fluorescent amplified fragment length polymorphism (fAFLP) analyses and genetic diversity in Litopenaeus vannamei (Penaeidae)

2005 ◽  
Vol 28 (2) ◽  
pp. 267-270 ◽  
Author(s):  
Michelle Mantovani Gonçalves ◽  
Manoel Victor Franco Lemos ◽  
Pedro Manoel Galetti Junior ◽  
Patrícia Domingues de Freitas ◽  
Manuel Antonio Andrade Furtado Neto
Keyword(s):  
Genetic Diversity ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Litopenaeus Vannamei ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism

Genetic diversity of fringed brome (Bromus ciliatus) as determined by amplified fragment length polymorphism

2005 ◽  
Vol 83 (10) ◽  
pp. 1322-1328 ◽  
Author(s):  
Yong-Bi Fu ◽  
Bruce E. Coulman ◽  
Yasas S.N. Ferdinandez ◽  
Jacques Cayouette ◽  
Paul M. Peterson
Keyword(s):  
Genetic Diversity ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Habitat Restoration ◽  
Fragment Length Polymorphism ◽  
Natural Populations ◽  
Germplasm Conservation ◽  
Amplified Fragment Length Polymorphism ◽  
Large Area ◽  
Geographic Origins

Fringed brome ( Bromus ciliatus L.) is found in native stands throughout a large area of North America. Little is known about the genetic diversity of this species. The amplified fragment length polymorphism (AFLP) technique was applied to assess the genetic diversity of 16 fringed brome populations sampled in Canada from the provinces of Alberta, British Columbia, Quebec, and Saskatchewan. Four AFLP primer pairs were employed to screen 82 samples with four to six samples per population and 83 polymorphic AFLP bands scored for each sample. The frequencies of the scored bands in all assayed samples ranged from 0.01 to 0.99 and averaged 0.53. Analysis of molecular variance revealed that 52.6% of the total AFLP variation resided among the 16 populations and 20.6% among the four provinces. The five Quebec populations appeared to be genetically the most diverse and distinct. The AFLP variability observed was significantly associated with the geographic origins of the fringed brome populations. These findings are useful for sampling fringed brome germplasm from natural populations for germplasm conservation and should facilitate the development of genetically diverse regional cultivars for habitat restoration and revegetation.

scholarly journals Genetic Diversity of Rhubarb Cultivars

2008 ◽  
Vol 133 (4) ◽  
pp. 587-592 ◽  
Author(s):  
Joseph C. Kuhl ◽  
Veronica L. DeBoer
Keyword(s):  
Genetic Diversity ◽  
Central Asia ◽  
Length Polymorphism ◽  
Genetic Relationship ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
18Th Century ◽  
Pedigree Information ◽  
Aflp Analysis ◽  
Fingerprint Analysis

The genus Rheum L., commonly known as rhubarb, is composed of ≈60 species, primarily distributed throughout northern and central Asia. Rhubarb species have been used for medicinal purposes for thousands of years; however, it was not until the 18th century that the culinary use of petioles was first reported. Although the origin(s) of culinary rhubarb is not clear, it is thought that they originated from hybridization of rhubarb species originally brought to Europe for medicinal purposes. Most rhubarb cultivars lack pedigree information, and the genetic relationship among cultivars is largely unknown. Amplified fragment length polymorphism (AFLP) markers were generated for fingerprint analysis of 37 cultivars and four putative Rheum species accessions. Ten EcoRI and MseI primer combinations were analyzed for a total of 1400 scored polymorphisms, with an average of 140 polymorphisms per primer combination. Results show at least two clusters of related cultivars, as well as distantly related accessions. This study provides an estimate of rhubarb cultivar genetic diversity using AFLP analysis.

Genetic diversity amongBradyrhizobiumisolates that effectively nodulate peanut (Arachis hypogaea)

1996 ◽  
Vol 42 (11) ◽  
pp. 1121-1130 ◽  
Author(s):  
Bruce E. Urtz ◽  
Gerald H. Elkan
Keyword(s):  
Genetic Diversity ◽  
Restriction Fragment Length Polymorphism ◽  
16S Rrna ◽  
Arachis Hypogaea ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Dna Homology ◽  
Symbiotic Gene ◽  
Restriction Fragment Length

Symbiotic gene diversity and other measures of genetic diversity were examined in Bradyrhizobium isolates that form an effective symbiosis with peanut (Arachis hypogaea). Initially, restriction fragment length polymorphism (RFLP) analysis using a nitrogenase (nif) gene probe was performed on 33 isolates along with one Bradyrhizobium elkanii and two Bradyrhizobium japonicum strains. Considerable diversity was observed among the RFLP patterns of many of the isolates, especially those from South America. Some isolates, however, were found to have similar nif and subsequent nod (nodulation) gene RFLP patterns, indicating symbiotic gene relatedness. With some noted exceptions, symbiotic gene relatedness correlated with relatedness based on total DNA homology and ribotyping analyses. Symbiotic gene relatedness also correlated with symbiotic effectiveness. The RFLP and DNA homology analyses indicate that bradyrhizobia effective with peanut are genetically diverse and consist of at least three different species. This diversity, however, was not particularly evident with partial 16S rRNA gene sequencing. Sequences obtained from the isolates were very similar to each other as well as to sequences previously reported for other Bradyrhizobium strains.Key words: Bradyrhizobium, nif, peanut, restriction fragment length polymorphism, 16S rRNA.

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