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The Scientific World Journal
Volume 2012 (2012), Article ID 368286, 14 pages
http://dx.doi.org/10.1100/2012/368286
Research Article

Genetic Diversity and Population Differentiation of the Causal Agent of Citrus Black Spot in Brazil

1Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina (EPAGRI), Estação Experimental de Itajaí, Rodovia Antônio Heil 8400, Itaipava, 88318-112 Itajaí, SC, Brazil
2Departamento de Fitossanidade, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, Universidade Estadual Paulista Via de Acesso Professor Dr. Paulo Donato Castellane s/n, 14884900 Jaboticabal, SP, Brazil
3Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, Universidade Estadual Paulista Via de Acesso Professor Dr. Paulo Donato Castellane s/n, 14884900 Jaboticabal, SP, Brazil

Received 31 October 2011; Accepted 5 January 2012

Academic Editors: D. B. Carlini and M. Chang

Copyright © 2012 Ester Wickert et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

One of the most important diseases that affect sweet orange orchards in Brazil is the Citrus Black Spot that is caused by the fungus Guignardia citricarpa. This disease causes irreparable losses due to the premature falling of fruit, as well as its severe effects on the epidermis of ripe fruit that renders them unacceptable at the fresh fruit markets. Despite the fact that the fungus and the disease are well studied, little is known about the genetic diversity and the structure of the fungi populations in Brazilian orchards. The objective of this work was study the genetic diversity and population differentiation of G. citricarpa associated with four sweet orange varieties in two geographic locations using DNA sequence of ITS1-5.8S-ITS2 region from fungi isolates. We observed that different populations are closely related and present little genetic structure according to varieties and geographic places with the highest genetic diversity distributed among isolates of the same populations. The same haplotypes were sampled in different populations from the same and different orange varieties and from similar and different origins. If new and pathogenic fungi would become resistant to fungicides, the observed genetic structure could rapidly spread this new form from one population to others.