Use of local rice cultivars as additional differentials to identify pathotypes of Pyricularia oryzae

Resumo

Eight additional rice cultivars as differentials were selected to identify pathotypes occurring in the Tocantins State. They were BRS Jaburu, BRS Taim, BRS Biguá, BR IRGA-417, Epagri 109, Javaé, Metica-1 and Supremo. These differentials were used in addition to the international set to determine the pathogenic diversity of 193 Pyricularia oryzae isolates collected dur- ing 1994-2002 from irrigated rice cultivars. They were conserved in Pyricularia culture collection of Embrapa Rice and Bean Research center. From 193 P. oryzae isolates 38 pathotypes were identified based on leaf blast reactions of international set and 29 pathotypes based on these additional differentials. The predominant pathotypes (TI-1, TG-2, TD-15 and TF-2) were represented by 53% of the tested isolates. The major international pathotypes (IB-45, IB-41, II-1 and ID-13) were represented by 43% of the isolates tested. The virulence pattern of 28 isolates belonging to the pathotype IB-45 was further differenti- ated into nine local pathotypes using additional set of differentials. The irrigated rice cultivars used as additional differentials serve as complementary set to identify pathotypes of interest for breeding blast resistant cultivars for Tocantins State.

Descrição

Palavras-chave

Pyricularia grisea, Resistance, Rice leaf blast, Oryza sativa, Virulence, Physiologic races, Differential varieties, Pyricularia grisea, Brusone, Raça fisiológica, Oryza sativa, Cultivares diferenciadoras, Virulência, Resistência

Citação

SILVA, Gisele Barata da; ARAÚJO, Leila Garcês de; LOBO, Valácia Lemes da Silva; PRABHU, Anne Sitarama; RÊGO, Marcela Cristiane Ferreira; PAES, Eduardo Tavares; FILIPPI, Marta Cristina Corsi de. Use of local rice cultivars as additional differentials to identify pathotypes of Pyricularia oryzae. Bragantia, Campinas, v. 70, n. 4, p. 860-868, 2011.