title: Genetic variability of Brazilian isolates of Alternaria alternata detected by AFLP and RAPD techniques.
abstract: The Alternaria brown spot (ABS) is a disease caused in tangerine plants and its hybrids by the fungus Alternaria alternata f. sp. citri which has been found in Brazil since 2001. Due to the recent occurrence in Brazilian orchards, the epidemiology and genetic variability of this pathogen is still an issue to be addressed. Here it is presented a survey about the genetic variability of this fungus by the characterization of twenty four pathogenic isolates of A. alternata f. sp. citri from citrus plants and four endophytic isolates from mango (one Alternaria tenuissima and three Alternaria arborescens). The application of two molecular markers Random Amplified Polymorphic DNA (RAPD) and Amplified Fragment Length Polymorphism (AFLP) had revealed the isolates clustering in distinct groups when fingerprintings were analyzed by Principal Components Analysis (PCA). Despite the better assessment of the genetic variability through the AFLP, significant modifications in clusters components were not observed, and only slight shifts in the positioning of isolates LRS 39/3 and 25M were observed in PCA plots. Furthermore, in both analyses, only the isolates from lemon plants revealed to be clustered, differently from the absence of clustering for other hosts or plant tissues. Summarizing, both RAPD and AFLP analyses were both efficient to detect the genetic variability within the population of the pathogenic fungus Alternaria spp., supplying information on the genetic variability of this species as a basis for further studies aiming the disease control.
authors.affiliation: Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo , Piracicaba, SP , Brasil.
authors.forename: Francisco
authors.initials: F
authors.lastname: Dini-Andreote
authors.forename: Vivian Cristina
authors.initials: VC
authors.lastname: Pietrobon
authors.forename: Fernando Dini
authors.initials: FD
authors.lastname: Andreote
authors.forename: Aline Silva
authors.initials: AS
authors.lastname: Romão
authors.forename: Marcel Bellato
authors.initials: MB
authors.lastname: Spósito
authors.forename: Welington Luiz
authors.initials: WL
authors.lastname: Araújo
keywords: Alternaria brown spot; PCA analysis; citrus plants; genetic variability; molecular markers
references.citation: Microbiol Res. 2005;160(1):13-26
references.pmid: 15782934
references.citation: Exp Parasitol. 2006 Nov;114(3):147-53
references.pmid: 16624308
references.citation: Parasitology. 2003 May;126(Pt 5):425-31
references.pmid: 12793646
references.citation: Syst Appl Microbiol. 2001 Dec;24(4):554-60
references.pmid: 11876363
references.citation: Nucleic Acids Res. 1990 Nov 25;18(22):6531-5
references.pmid: 1979162
references.citation: Methods Mol Biol. 2004;270:173-86
references.pmid: 15153627
references.citation: Phytopathology. 2000 Apr;90(4):407-14
references.pmid: 18944592
references.citation: Mycol Res. 2006 Nov;110(Pt 11):1290-300
references.pmid: 17077026
references.citation: Nucleic Acids Res. 1995 Nov 11;23(21):4407-14
references.pmid: 7501463