RESUMO
Isolates of Pyricularia grisea from wheat (Triticum aestivum Lam.) and triticale (x Triticosecale Wittmack) spikes with blast symptoms were analyzed by classical (VCG) and molecular (RAPD) techniques. P. grisea mutants, unable to use sodium nitrate (nit) as nitrogen source, were obtained with potassium chlorate. For vegetative compatibility (VCG) tests, genetically complementary nit mutant pairs were inoculated in a medium with sodium nitrate as a single nitrogen source. P. grisea isolates were divided into two vegetative compatibility groups and two RAPD groups. Since vegetative compatible strains may mutually exchange genetic and cytoplasmatic material, the contribution of the parasexual cycle in the genetic variability of Brazilian P. grisea isolates is discussed.
Assuntos
DNA Fúngico/genética , Grão Comestível/microbiologia , Magnaporthe/isolamento & purificação , Triticum/microbiologia , Brasil , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiologia , Genes Fúngicos , Teste de Complementação Genética , Variação Genética , Magnaporthe/genética , Magnaporthe/metabolismo , Magnaporthe/fisiologia , Nitratos/metabolismo , Nitrogênio/metabolismo , Doenças das Plantas/microbiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Recombinação GenéticaRESUMO
Se analizaron por técnicas clásica (VCG) y molecular (RAPD) aislamientos dePyricularia grisea de las espigas de trigo (Triticum aestivum Lam.) y triticale(x Triticosecale Wittmack) con los síntomas de piricularia o bruzone.Los mutantes de P. grisea, incapaces de utilizar nitratos como fuente denitrógeno (nit), fueron obtenidos con clorato de potasio. Para las pruebasde compatibilidad vegetativa (VCG) se inocularon los pares complementariosde mutantes nit en un medio con nitrato de sodio como única fuente denitrógeno. Los aislamientos de P. grisea fueron separados en dos gruposde compatibilidad vegetativa y dos de RAPD. Considerándose que losaislamientos compatibles de P. grisea pueden intercambiar materialesnucleares y citoplasmáticos entre sí, se discute la contribución del cicloparasexual en la variabilidad genética de los aislamientos brasileños deP. grisea(AU)
Isolates of Pyricularia grisea from wheat (Triticum aestivum Lam.) and triticale(x Triticosecale Wittmack) spikes with blast symptoms were analyzed byclassical (VCG) and molecular (RAPD) techniques. P. grisea mutants, unable touse sodium nitrate (nit) as nitrogen source, were obtained with potassiumchlorate. For vegetative compatibility (VCG) tests, genetically complementarynit mutant pairs were inoculated in a medium with sodium nitrate as a singlenitrogen source. P. grisea isolates were divided into two vegetativecompatibility groups and two RAPD groups. Since vegetative compatiblestrains may mutually exchange genetic and cytoplasmatic material, thecontribution of the parasexual cycle in the genetic variability of BrazilianP. grisea isolates is discussed(AU)
