scholarly journals High genetic diversity and poor in vitro response to antifungals of clinical strains of Fusarium oxysporum

2009 ◽  
Vol 63 (6) ◽  
pp. 1152-1155 ◽  
Author(s):  
M. Azor ◽  
J. Cano ◽  
J. Gene ◽  
J. Guarro
Keyword(s):  
Genetic Diversity ◽  
Fusarium Oxysporum ◽  
High Genetic Diversity ◽  
Clinical Strains ◽  
In Vitro Response

Conservation of Billbergia zebrina genetic resources: AFLP polymorphism of in vitro regenerated genotypes

2011 ◽  
Vol 10 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Lirio L. Dal Vesco ◽  
Valdir M. Stefenon ◽  
Leocir J. Welter ◽  
Neusa Steiner ◽  
Miguel P. Guerra
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Gene Diversity ◽  
Plant Genetic Resources ◽  
Natural Populations ◽  
Shannon Index ◽  
Aflp Markers ◽  
High Genetic Diversity ◽  
Index Of Diversity

Biotechnological techniques comprise useful tools for the conservation of endangered plant genetic resources. In the present work, polymorphism and usefulness of amplified fragment length polymorphism (AFLP) markers in assessing the genetic diversity in populations of Billbergia zebrina were investigated in nodular cultures and adult plants of the species. AFLP markers revealed moderate-to-high genetic diversity based on the estimations of Nei's gene diversity (mean He = 0.28), Shannon index of diversity (mean HS = 0.48) and the number of polymorphic fragments (mean of 56.17 polymorphic fragments over six primer pairs). In comparison to published studies of population genetics performed in other bromeliad species, the present study suggests that natural populations of B. zebrina likely maintain high levels of genetic diversity, an important feature towards conservation of plant genetic resources. The results obtained reveal that AFLP markers comprise a powerful tool in order to assess the levels of genetic diversity in natural populations of this endangered species. Integrating AFLP markers with in vitro propagation techniques is understood as an adequate strategy for conservation programmes of this species.

scholarly journals Aggressiveness and Fungicide Sensitivity of Alternaria dauci from Cultivated Carrot

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 405-412 ◽  
Author(s):  
P. M. Rogers ◽  
W. R. Stevenson
Keyword(s):  
Genetic Diversity ◽  
Disease Susceptibility ◽  
Phenotypic Diversity ◽  
Fungicide Sensitivity ◽  
Northeastern North America ◽  
Alternaria Leaf Blight ◽  
Leaf Chlorosis ◽  
Alternaria Dauci ◽  
In Vitro Response

Isolates of Alternaria dauci causing Alternaria leaf blight (ALB) were collected from commercial carrot (Daucus carota var. sativus) fields in northeastern North America during 2004. Twenty-two isolates representing a range of genetic diversity were analyzed for their aggressiveness on three commercial carrot varieties (Bolero, Enterprise, and Heritage) varying in disease susceptibility as well as their in vitro response to three fungicides (azoxystrobin, chlorothalonil, and boscalid) commonly used for ALB control. Severity of leaf and petiole blight and leaf chlorosis varied among isolates and carrot varieties in each of three experiments. Visible differences in disease severity, which ranged from 10.9 to 45.1% of the leaf area affected, were apparent 16 days after inoculation. Intensity of chlorosis correlated strongly with blight severity among all isolates. Significant differences were noted among carrot varieties in response to ALB. These varieties may prove useful as differentials capable of distinguishing isolates because variety by isolate interactions were detected. Inhibition of conidial germination ranged from 0.01 to 0.37 μg/ml for azoxystrobin, 0.009 to 0.08 μg/ml for chlorothalonil, and 0.09 to 0.59 μg/ml for boscalid. On average, isolates were more sensitive to chlorothalonil than to azoxystrobin and boscalid. No significant correlation was noted between fungicide sensitivity and aggressiveness. These data provide evidence for phenotypic diversity among A. dauci isolates collected from areas of commercial carrot production.

scholarly journals In vivo and in vitro models show unexpected degrees of virulence among Toxoplasma gondii type II and III isolates from sheep

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Mercedes Fernández-Escobar ◽  
Rafael Calero-Bernal ◽  
Javier Regidor-Cerrillo ◽  
Raquel Vallejo ◽  
Julio Benavides ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Toxoplasma Gondii ◽  
Small Ruminants ◽  
Parasite Burden ◽  
Target Cells ◽  
Post Inoculation ◽  
Type Ii ◽  
High Genetic Diversity

AbstractToxoplasma gondii is an important zoonotic agent with high genetic diversity, complex epidemiology, and variable clinical outcomes in animals and humans. In veterinary medicine, this apicomplexan parasite is considered one of the main infectious agents responsible for reproductive failure in small ruminants worldwide. The aim of this study was to phenotypically characterize 10 Spanish T. gondii isolates recently obtained from sheep in a normalized mouse model and in an ovine trophoblast cell line (AH-1) as infection target cells. The panel of isolates met selection criteria regarding such parameters as genetic diversity [types II (ToxoDB #1 and #3) and III (#2)], geographical location, and sample of origin (aborted foetal brain tissues or adult sheep myocardium). Evaluations of in vivo mortality, morbidity, parasite burden and histopathology were performed. Important variations between isolates were observed, although all isolates were classified as “nonvirulent” (< 30% cumulative mortality). The isolates TgShSp16 (#3) and TgShSp24 (#2) presented higher degrees of virulence. Significant differences were found in terms of in vitro invasion rates and tachyzoite yield at 72 h post-inoculation (hpi) between TgShSp1 and TgShSp24 isolates, which exhibited the lowest and highest rates, respectively. The study of the CS3, ROP18 and ROP5 loci allelic profiles revealed only type III alleles in ToxoDB #2 isolates and type II alleles in the #1 and #3 isolates included. We concluded that there are relevant intra- and inter-genotype virulence differences in Spanish T. gondii isolates, which could not be inferred by genetic characterization using currently described molecular markers.

scholarly journals Performance of Putative Mutants and Genetic Parameters of Plectranthus amboinicus (L.) through Mutation Induction With Colchicine

2021 ◽  
Vol 5 (2) ◽  
pp. 89-99
Author(s):  
Kunto Wibisono ◽  
Syarifah Iis Aisyah ◽  
Waras Nurcholis ◽  
Sri Suhesti
Keyword(s):  
Genetic Diversity ◽  
Genetic Parameters ◽  
Leaf Length ◽  
Genetic Enhancement ◽  
Mutation Induction ◽  
High Genetic Diversity ◽  
Induced Mutation ◽  
Qualitative Characters ◽  
Plectranthus Amboinicus

Genetic enhancement in vegetatively propagated crops can be done through mutation induction. Colchicine-induced mutation is one of the methods that can be employed to increase plant genetic diversity. This study aimed to determine the effect of colchicine on the performance and genetic parameters of MV3 generation of Plectranthus amboinicus (L.). This study was conducted at the Laboratory of Agricultural Seed Management, Plantation Research and Development Center, from June 2018 to June 2019. Nodes and shoots were used as explants. Mutation induction was performed using colchicine at concentrations of 0%, 0.02%, 0.04%, and 0.06%. Explant regeneration and subculture were done on MS0 medium. The number of plantlets yielded were 59 (0% concentration of colchicine), 60 (0.02%), 81 (0.04%), and 80 plantlets (0.06%), respectively. Results indicated that colchicine-induced mutation in an in vitro culture was able to generate high genetic diversity in both quantitative and qualitative characters of the plantlets. At the concentration of 0.04%, colchicine produced the highest frequency of putative mutants (28.4%). Genetic parameters in MV3 generation of P. amboinicus plantlets showed that five quantitative characters, i.e. plantlet height, number of leaves, number of shoots, leaf length, and number of roots had high heritability values at a concentration around the LC50 value (0.0275%).

scholarly journals Genomic analysis of the diversity, antimicrobial resistance and virulence potential of clinical Campylobacter jejuni and Campylobacter coli strains from Chile

2020 ◽  
Author(s):  
Veronica Bravo ◽  
Assaf Katz ◽  
Lorena Porte ◽  
Thomas Weitzel ◽  
Carmen Varela ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Antimicrobial Resistance ◽  
South America ◽  
Campylobacter Jejuni ◽  
Virulence Factors ◽  
Epidemiological Data ◽  
Campylobacter Coli ◽  
Genome Sequences ◽  
High Genetic Diversity ◽  
Clinical Strains

ABSTRACTCampylobacter jejuni and Campylobacter coli are the leading cause of human gastroenteritis in the industrialized world and an emerging threat in developing countries. The incidence of campylobacteriosis in South America is greatly underestimated, mostly due to the lack of adequate diagnostic methods. Accordingly, there is limited genomic and epidemiological data from this region. In the present study, we performed a genome-wide analysis of the genetic diversity, virulence, and antimicrobial resistance of the largest collection of clinical C. jejuni and C. coli strains from Chile available to date (n=81), collected in 2017-2019 in Santiago, Chile. This culture collection accounts for over a third of the genome sequences available of clinical strains from South America. cgMLST analysis identified high genetic diversity as well as 13 novel STs and alleles in both C. jejuni and C. coli. Pangenome and virulome analyses showed a differential distribution of virulence factors, including both plasmid and chromosomally encoded T6SSs and T4SSs. Resistome analysis predicted widespread resistance to fluoroquinolones, but low rates of erythromycin resistance. This study provides valuable genomic and epidemiological data and highlights the need for further genomic epidemiology studies in Chile and other South American countries to better understand molecular epidemiology and antimicrobial resistance of this emerging intestinal pathogen.AUTHOR SUMMARYCampylobacter is the leading cause of bacterial gastroenteritis worldwide and an emerging and neglected pathogen in South America. In this study, we performed an in-depth analysis of the genome sequences of 69 C. jejuni and 12 C. coli clinical strains isolated from Chile, which account for over a third of the sequences from clinical strains available from South America. We identified a high genetic diversity among C. jejuni strains and the unexpected identification of clade 3 C. coli strains, which are infrequently isolated from humans in other regions of the world. Most strains harbored the virulence factors described for Campylobacter. While ~40% of strains harbored mutation in the gyrA gene described to confer fluoroquinolone resistance, very few strains encoded the determinants linked to macrolide resistance, currently used for the treatment of campylobacteriosis. Our study contributes to our knowledge of this important foodborne pathogen providing valuable data from South America.

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