title: Population Genetic Structure of Rhizoctonia oryzae-sativae from Rice in Latin America and Its Adaptive Potential to Emerge as a Pathogen on Urochloa Pastures.
abstract: The fungus Rhizoctonia oryzae-sativae is an important pathogen that causes the aggregated sheath spot disease on rice. In this study, we investigated the genetic structure of rice-adapted populations of R. oryzae-sativae sampled from traditional rice-cropping areas from the Paraíba Valley, São Paulo, Brazil, and from Meta, in the Colombian Llanos, in South America. We used five microsatellite loci to measure population differentiation and infer the pathogen's reproductive system. Gene flow was detected among the three populations of R. oryzae-sativae from lowland rice in Brazil and Colombia. In contrast, a lack of gene flow was observed between the lowland and the upland rice populations of the pathogen. Evidence of sexual reproduction including low clonality, Hardy-Weinberg equilibrium within loci and gametic equilibrium between loci, indicated the predominance of a mixed reproductive system in all populations. In addition, we assessed the adaptive potential of the Brazilian populations of R. oryzae-sativae to emerge as a pathogen to Urochloa spp. (signalgrass) based on greenhouse aggressiveness assays. The Brazilian populations of R. oryzae-sativae were probably only incipiently adapted as a pathogen to Urochloa spp. Comparison between RSTand QSTshowed the predominance of diversifying selection in the divergence between the two populations of R. oryzae-sativae from Brazil.
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Danilo A Dos Santos
authors: DA
authors: Pereira
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Paulo C
authors: PC
authors: Ceresini
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Vanina L
authors: VL
authors: Castroagudín
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Lina M
authors: LM
authors: Ramos-Molina
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Edisson
authors: E
authors: Chavarro-Mesa
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Matheus Mereb
authors: MM
authors: Negrisoli
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Samara Nunes
authors: SN
authors: Campos
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Mauro E S
authors: ME
authors: Pegolo
authors: First, second, third, sixth, seventh and eighth authors, UNESP University of São Paulo State, Campus de Ilha Solteira, SP, Brazil; fourth and fifth authors, UNESP Campus de Jaboticabal, SP, Brazil; eighth author, APTA/IAC, Agronomic Institute of Campinas, Vale do Paraíba Regional Center, Pindamonhangaba, SP, Brazil.
authors: Hélio Minoru
authors: HM
authors: Takada
mesh_terms: D001938:Brazil; D051456:Gene Flow; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D018895:Microsatellite Repeats / Q000235:genetics; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D006109:Poaceae / Q000382:microbiology*; D012232:Rhizoctonia / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity
keywords: Brachiaria; aggregated sheath spot; forage pastures; gene flow; reproductive system