Genetic Structure of Phytophthora capsici populations in the Northeast of Buenos Aires province, Argentina

• IRIBARREN LIÑEIRO, MARIA JOSEFINA ^[1]
  1. [1] Universidad Nacional de Luján

     Universidad Nacional de Luján

     Argentina

     
• Localización: Revista de Investigaciones Agropecuarias, ISSN 0325-8718, ISSN-e 1669-2314, Vol. 42, Nº. 1, 2016
• Idioma: inglés
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• Resumen

  • Phytophthora capsici causes destructive diseases worldwide. The pathogen is heterothallic and the two mating types (MTs) are required for sexual reproduction. MTs rates vary amongst geographical regions and so does the chance for sexual reproduction. Taking into account that the durability of control measures depends upon genetic variation, it is advisable to consider the quantity and distribution of genetic variation within and between the species population; the genetic structure. This is determined by factors that influence the population evolution like mutation, genetic drift, genetic flux, reproduction system and selection. In these regards, little is known about P. capsici populations in Argentina. The objective was to evaluate the genetic variability of P. capsici isolates from three horticultural production sites of the Northeast of Buenos Aires. Sixty one isolates of P. capsici collected from Capsicum annuum, Solanum melongena, Solanum lycopersicum and Cucurbita spp. crops were morphologically identified and analyzed for MTs. The isolates were further identified via molecular techniques based on the sequences of the ITS1 - 5.8S - ITS2 region of the ADNr. Los haplotypes were defined for all the isolates. The number and diversity of haplotypes, the number of polymorphic sites and recombination events, and the genetic structure of P. capsici were subsequently estimated. Phylogenetic network reconstruction was assayed using Network 4.6.1.0.All isolates showed morphological and genetic characteristics of P. capsici and belonged to the A1 MT. No differences were observed among isolates from different hosts, but the DNA data showed evidence of recombination and high levels of variability among sites.