The Urochloa Foliar Blight and Collar Rot Pathogen Rhizoctonia solani AG-1 IA Emerged in South America Via a Host Shift from Rice

Autor(es)

Mesa, Eclisson Chavarro ^[1] ; Ceresini, Paulo C. ^[2] ; Molina, Lina M. Ramos ^[1] ; Pereira, Danilo A. S. ^[2] ; Schurt, Daniel A. ^[3] ; Vieira, Jr., Jose R. ^[4] ; Poloni, Nadia M. ^[2] ; McDonald, Bruce A. ^[5]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo State, UNESP, Sao Paulo, SP - Brazil

^[2] Univ Estadual Paulista, Sao Paulo, SP - Brazil

^[3] EMBRAPA Brazilian Agr Res Corp, Boa Vista, RR - Brazil

^[4] EMBRAPA, Porto Velho, RO - Brazil

^[5] Swiss Fed Inst Technol, Inst Integrat Biol, Zurich - Switzerland

• Tipo de documento: Artigo Científico
• Fonte: PHYTOPATHOLOGY; v. 105, n. 11, p. 1475-1486, NOV 2015.
• Citações Web of Science: 5

Resumo

The fungus Rhizoctonia solani anastomosis group (AG)-1 IA emerged in the early 1990s as an important pathogen causing foliar blight and collar rot on pastures of the genus Urochloa (signalgrass) in South America. We tested the hypothesis that this pathogen emerged following a host shift or jump as a result of geographical overlapping of host species. The genetic structure of host and regional populations of R. solani AG-1 IA infecting signalgrass, rice, and soybean in Colombia and Brazil was analyzed using nine microsatellite loci in 350 isolates to measure population differentiation and infer the pathogen reproductive system. Phylogeographical analyses based on the microsatellite loci and on three DNA sequence loci were used to infer historical migration patterns and test hypotheses about the origin of the current pathogen populations. Cross pathogenicity assays were conducted to measure the degree of host specialization in populations sampled from different hosts. The combined analyses indicate that the pathogen populations currently infecting Urochloa in Colombia and Brazil most likely originated from a population that originally infected rice. R. solani AG-1 IA populations infecting Urochloa exhibit a mixed reproductive system including both sexual reproduction and long-distance dispersal of adapted clones, most likely on infected seed. The pathogen population on Urochloa has a genetic structure consistent with a high evolutionary potential and showed evidence for host specialization. (AU)

• Processo FAPESP: 13/11944-0 - Estrutura genética de populações de Rhizoctonia oryzae-sativae do arroz no Vale do Paraíba, SP, e potencial adaptativo do patógeno à Brachiaria.
• Beneficiário: Danilo Augusto dos Santos Pereira
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 11/23050-8 - A origem de populações emergentes do patógeno da queima da folha da Brachiaria spp. (Rhizoctonia solani AG-1 IA) na Amazônia e seu potencial de adaptação a outros agroecossistemas brasileiros
• Beneficiário: Edisson Chavarro Mesa
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/50150-3 - A origem de populações emergentes do patógeno da queima da folha da Brachiaria spp. (Rhizoctonia solani AG-1) na Amazônia e seu potencial de adaptação a outros agroecossistemas brasileiros
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular