The Magnaporthe grisea species complex and plant pathogenesis.

TAXONOMY: Kingdom Fungi; Phylum Ascomycota; Class Sordariomycetes; Order Magnaporthales; Family Pyriculariaceae (anamorph)/Magnaporthaceae (teleomorph); Genus Pyricularia (anamorph)/Magnaporthe (teleomorph); Species P. grisea (anamorph)/M. grisea (teleomorph). HOST RANGE: Very broad at the species level, including rice, wheat, barley, millet and other species of the Poaceae (Gramineae). DISEASE SYMPTOMS: Can be found on all parts of the plant, including leaves, leaf collars, necks, panicles, pedicels, seeds and even the roots. Initial symptoms are white to grey-green lesions or spots with darker borders, whereas older lesions are elliptical or spindle-shaped and whitish to grey with necrotic borders. Lesions may enlarge and coalesce to eventually destroy the entire leaf. DISEASE CONTROL: Includes cultural strategies, genetic resistance and the application of chemical fungicides. GEOGRAPHICAL DISTRIBUTION: Widespread throughout the rice-growing regions of the globe and has been reported in more than 85 countries. GENOMIC STRUCTURE: Different isolates possess similar genomic sizes and overall genomic structures. For the laboratory strain 70-15: assembly size, 40.98 Mb; number of chromosomes, seven; number of predicted genes, 13 032; G + C composition, 51.6%; average gene contains 451.6 amino acids; mitochondrion genome size, 34.87 kb. USEFUL WEBSITE: http://www.broadinstitute.org/annotation/genome/magnaporthe_comparative/MultiHome.html.