Population Genetic Structure of Rhizoctonia oryzae-sativae from Rice in Latin America and Its Adaptive Potential to Emerge as a Pathogen on Urochloa Pastures

Author(s)

dos Santos Pereira, Danilo A. ; Ceresini, Paulo C. ; Castroagudin, Vanina L. ; Ramos-Molina, Lina M. ; Chavarro-Mesa, Edisson ; Negrisoli, Matheus Mereb ; Campos, Samara Nunes ; Pegolo, Mauro E. S. ; Takada, Helio Minoru

• Document type: Journal article
• Source: PHYTOPATHOLOGY; v. 107, n. 1, p. 121-131, JAN 2017.
• Web of Science Citations: 2

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. oryzaesativae sampled from traditional rice-cropping areas from the Paraiba Valley, Sao 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 R-ST and Q(ST) showed the predominance of diversifying selection in the divergence between the two populations of R. oryzaesativae from Brazil. (AU)

• FAPESP's process: 13/11944-0 - Population genetic structure of Rhizoctonia oryzae-sativae from rice in the Paraíba Valley, SP, and adaptive potential of the pathogen to Brachiaria.
• Grantee: Danilo Augusto dos Santos Pereira
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/25904-2 - The rise of Pyricularia tritici sp. Nov. as the wheat blast pathogen in Brazil: sympatric speciation inferred from multilocus gene phylogeny, pathogenicity spectra and avirulence genes evolution
• Grantee: Vanina Lilián Castroagudin
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/23050-8 - The origin of the emerging populations of the Brachiaria collar rot pathogen (Rhizoctonia solani AG-1 IA) in the Amazon and its potential for adaptation to another Brazilian agroecosystem
• Grantee: Edisson Chavarro Mesa
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/50150-3 - The origin of the emerging populations of the Brachiaria collar rot pathogen (Rhizoctonia solani AG-1 IA) in the Amazon and its potential for adaptation to another Brazilian agroecosystem
• Grantee: Paulo Cezar Ceresini
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants