Browsing by Author "Rodrigues Jr., Carlos J."
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- Genetic diversity in Hemileia vastatrixbased on RAPD markersPublication . Gouveia, M. Manuela C.; Ribeiro, Ana; Várzea, Vítor M. P.; Rodrigues Jr., Carlos J.Random amplified polymorphic DNA (RAPD) was used to assess the genetic structure of Hemileia vastatrix populations. Forty-five rust iso lates with different virulence spectra and from dif ferent hosts and geographical regions were ana lyzed. Out of 45 bands, generated with three RAPD primers, 35 (78%) were polymorphic and scored as molecular markers. Cluster analysis exhibits unstruc tured variability of this pathogen with regard to physiological race, geographical origin or host. The genotypic diversity (H9) inferred from Shannon’s in dex was higher than gene diversity (Ht), suggesting that diversity is distributed among clonal lineages. Estimates of gene diversity in Africa and Asia pop ulations were higher in total (Ht) as compared to within population diversity (Hs). Genetic differen tiation was considerable among coffee rust isolates from Africa (Gst 5 0.865) and Asia (Gst 5 0.768) but not among isolates from South America (Gst 5 0.266). We concluded that genetic diversity in H. vastatrix was moderately low and that the genetic differentiation among populations shows that asex ual reproduction is likely to play an important role in the population biology of this fungus. This should be taken into account for the development of breed ing programs.