Pyricularia graminis-tritici, a new Pyricularia species causing wheat blast

Autor(es)

Castroagudin, V. L. ; Moreira, S. I. ; Pereira, D. A. S. ; Moreira, S. S. ; Brunner, P. C. ; Maciel, J. L. N. ; Crous, P. W. ; McDonald, B. A. ; Alves, E. ; Ceresini, P. C.

• Tipo de documento: Artigo Científico
• Fonte: PERSOONIA; v. 37, p. 199-216, DEC 2016.
• Citações Web of Science: 20

Resumo

Pyricularia oryzae is a species complex that causes blast disease on more than 50 species of poaceous plants. Pyricularia oryzae has a worldwide distribution as a rice pathogen and in the last 30 years emerged as an important wheat pathogen in southern Brazil. We conducted phylogenetic analyses using 10 housekeeping loci for 128 isolates of P. oryzae sampled from sympatric populations of wheat, rice, and grasses growing in or near wheat fields. Phylogenetic analyses grouped the isolates into three major clades. Clade 1 comprised isolates associated only with rice and corresponds to the previously described rice blast pathogen P. oryzae pathotype Oryza (PoO). Clade 2 comprised isolates associated almost exclusively with wheat and corresponds to the previously described wheat blast pathogen P. oryzae pathotype Triticum (PoT). Clade 3 contained isolates obtained from wheat as well as other Poaceae hosts. We found that Clade 3 is distinct from P. oryzae and represents a new species, Pyricularia graminis-tritici (Pgt). No morphological differences were observed among these species, but a distinctive pathogenicity spectrum was observed. Pgt and PoT were pathogenic and highly aggressive on Triticum aestivum (wheat), Hordeum vulgare (barley), Urochloa brizantha (signal grass), and Avena sativa (oats). PoO was highly virulent on the original rice host (Oryza sativa), and also on wheat, barley, and oats, but not on signal grass. We conclude that blast disease on wheat and its associated Poaceae hosts in Brazil is caused by multiple Pyricularia species. Pyricularia graminis-tritici was recently found causing wheat blast in Bangladesh. This indicates that P. graminis-tritici represents a serious threat to wheat cultivation globally. (AU)

• Processo FAPESP: 13/10655-4 - Desvendando a origem local da brusone do trigo (Magnaporthe oryzae) no Centro Sul do Brasil e evidências da emergência de resistência a fungicidas estrobilurinas em populações do patógeno
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/25904-2 - A emergência de Pyricularia tritici sp. Nov. como patógeno da brusone do trigo no Brasil: especiação simpátrica inferida por filogenia multiloci, espectro de patogenicidade e evolução de genes de virulência
• Beneficiário: Vanina Lilián Castroagudin
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/10453-8 - A emergência de Pyricularia tritici sp. Nov. como patógeno da brusone do trigo no Brasil: especiação simpátrica inferida por filogenia multiloci, espectro de patogenicidade e evolução de genes de virulência
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular