Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Pyricularia grisea: a new pathogen of Brachiaria brizantha cv. Marandu in Pará.

Abstract

In Rondon do Pará (Pará) and Maranhão, Brazil, mortality of 80-90% of B. brizantha [Urochloa brizantha] plants was observed. Plant leaves (approximately 60 days old) collected from both locations had lesions that coalesced to form a large necrotic area, resulting in total leaf burn. The pathogen isolated from infected tissues was identified as P. grisea [Magnaporthe grisea], which infects more than 50 grass species, including rice and wheat. The pathogen was inoculated into 30-day-old healthy plants, and the symptoms were reproduced at 8 days after inoculation. P. grisea was also detected in 8% of the seed samples used for planting in Rondon do Pará. This is thought to be the first report of the occurrence of P. grisea in B. brizantha in the Amazon.