title: Distribution of mating-type alleles and M13 PCR  markers in the black leaf spot fungus Mycosphaerella fijiensis of  bananas in Brazil.
abstract: The fungus Mycosphaerella fijiensis is the  causative agent of black sigatoka, which is one of the most destructive  diseases of banana plants. Infection with this pathogen results in  underdeveloped fruit, with no commercial value. We analyzed the distribution of  the M. fijiensis mating-type system and its genetic variability using  M13 phage DNA markers. We found a 1:1 distribution of mating-type alleles,  indicating MAT1-1 and MAT1-2 idiomorphs. A polymorphism analysis  using three different primers for M13 markers showed that only the M13  minisatellite primers generated polymorphic products. We then utilized this  polymorphism to characterize 40 isolates from various Brazilian states. The  largest genetic distances were found between isolates from the same location  and between isolates from different parts of the country. Therefore, there was  no correlation between the genetic similarity and the geographic origin of the  isolates. The M13 marker was used to generate genetic fingerprints for five  isolates; these fingerprints were compared with the band profiles obtained from  inter-simple sequence repeat (UBC861) and inter-retrotransposon amplified  polymorphism analyses. We found that the M13 marker was more effective than the  other two markers for differentiating these isolates.
authors: Laboratório de Biologia Molecular, Embrapa Amazônia Ocidental, Manaus, AM, Brasil.
authors: C B
authors: CB
authors: Queiroz
authors: E C
authors: EC
authors: Miranda
authors: R E
authors: RE
authors: Hanada
authors: N R
authors: NR
authors: Sousa
authors: L
authors: L
authors: Gasparotto
authors: M A
authors: MA
authors: Soares
authors: G F
authors: GF
authors: Silva
mesh_terms: D000483:Alleles; D001203:Ascomycota / Q000235:genetics*; D017104:Bacteriophage M13 / Q000235:genetics*; D001938:Brazil; D005656:Fungal Proteins / Q000235:genetics; D049770:Genes, Mating Type, Fungal; D005819:Genetic Markers / Q000235:genetics*; D018895:Microsatellite Repeats; D018598:Minisatellite Repeats; D028521:Musa / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic
chemical_list: D005656:Fungal Proteins; D005819:Genetic Markers