title: Characterization of Phytophthora nicotianae isolates in southeast Spain and their detection and quantification through a real-time TaqMan PCR.
abstract: BACKGROUND
  The soil-borne pathogens Phytophthora nicotianae and P. capsici are the causal agents of root and stem rot of many plant species. Although P. capsici was considered the causal agent in one of the main pepper production areas of Spain to date, evidence of the presence of P. nicotianae was found. We aimed to survey the presence of P. nicotianae and study the variability in its populations in this area in order to improve the management of Tristeza disease.
  
  
  RESULTS
  A new specific primer and a TaqMan probe were designed based on the internal transcribed spacer regions of ribosomal DNA to detect and quantify P. nicotianae. Both morphological and molecular analysis showed its presence and confirmed it to be the causal agent of the Phytophthora disease symptoms in the studied area. The genetic characterization among P. nicotianae populations showed a low variability of genetic diversity among the isolates. Only isolates of the A2 mating type were detected.
  
  
  CONCLUSIONS
  Not only is a specific and early detection of P. nicotianae essential but also the study of genetic variability among isolates for the appropriate management of the disease, above all, in producing areas with favorable conditions for the advance of the disease.
authors.affiliation: Department of Soil and Water Conservation and Organic Wastes Management, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), 30100, Espinardo, Murcia, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Blaya
authors.forename: Carmen
authors.initials: C
authors.lastname: Lacasa
authors.forename: Alfredo
authors.initials: A
authors.lastname: Lacasa
authors.forename: Victoriano
authors.initials: V
authors.lastname: Martínez
authors.forename: Ana B
authors.initials: AB
authors.lastname: Santísima-Trinidad
authors.forename: Jose A
authors.initials: JA
authors.lastname: Pascual
authors.forename: Margarita
authors.initials: M
authors.lastname: Ros
mesh_terms: D002212:Capsicum / Q000382:microbiology*; D017931:DNA Primers / Q000032:analysis; D004271:DNA, Fungal / Q000032:analysis*; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D049770:Genes, Mating Type, Fungal; D014644:Genetic Variation; D010802:Phylogeny; D010838:Phytophthora / Q000235:genetics* / Q000302:isolation & purification; D010935:Plant Diseases / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013030:Spain
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer
keywords: Phytophthora nicotianae; TaqMan real-time PCR; Tristeza disease; genetic diversity; mitochondrial DNA