Abstract
The present taxonomic study involved approximately 1200 isolates of Fusarium which were received by the writer from time to time each year during the past 25 years from tropical and temperate regions. The various isolates originated in 59 geographic areas. Approximately 90% of the isolates were obtained from a total of 160 species of host plants which included cultivated and non-cultivated plants. The cultivated plants included the chief agricultural crops grown in tropical and temperate regions, respectively. About 10% of the isolates were obtained from miscellaneous habitats, e.g. soil, water, insects, wood pulp, fowl, dairy products, and human tissue.A total of 26 species, 4 varieties, and 17 formae of Fusarium, classified in 12 sections of the genus, were identified among the isolates. These species, varieties, and formae are: F. aquaeductuum (Radlk. & Rabh. pr.p) Lagh., F. dimerum Penz., F. merismoides Cda. (section Eupionnotes); F. decemcellulare Brick (section Spicarioides); F. nivale (Fr.) Ces. (section Arachnites); F. chlamydosporum Wr. & Rg., F. poae (Cda.) Sacc., F. sporotrichioides Sherb. (section Sporotrichiella); F. arthrosporioides Sherb., F. avenaceum (Fr.) Sacc. (section Roseum); F. semitectum Berk. & Rav. (section Arthrosporiella); F. acuminatum (Ell. & Everh.) Wr., F. compactum (Wr.) Gordon, F. equiseti (Cda.) Sacc, F. longipes Wr. (section Gibbosum); F. culmorum (W. G. Sm.) Sacc, F. graminearum Schwabe, F. heterosporum Nees emend. Raillo; F. sambucinum Fuckel, F. s. var. coeruleum Wr., F. s. forma 6 Wr., F. tumidum Sherb. (section Discolor); F. lateritium Nees, F. l. forma cajani (Padw.) Gordon, F. l. forma crotalariae (Padw.) Gordon, F. stilboides Wr. (section Lateritium); F. moniliforme Sheld., F. m. var. anthophilum (A. Br.) Wr., F. m. var. subglutinans Wr. & Rg. (section Liseola); F. oxysporum Schl. emend. Snyder & Hansen, F. oxysporum var. redolens (Wr.) Gordon; F. oxysporum forma callistephi (Beach) S. & H.; forma cepae (Hanz.) S. & H., forma dianthi (Prill. & Del.) S. & H., forma gladioli (Massey) S. & H., forma lini (Bolley) S. & H., forma lycopersici (Sacc.) S. & H., forma nicotianae (Johns.) S. & H., forma niveum (E. F. S.) S. & H., forma passiflorae Purss, forma pini (Hartig) S. & H., forma pisi (Lindf.) S. & H., forma tuberosi S. & H., forma vasinfectum (Atk.) S. & H. (section Elegans); F. coeruleum (Lib.) Sacc, F. solani (Mart.) App. & Wr. emend. S. & H. (section Martiella).As indicated by the number of geographic areas and habitats from which they were obtained, the six species most widely distributed were F. solani, F. oxysporum, F. equiseti, F. moniliforme, F. avenaceum, and F. semitectum. Five species, namely F. aquaeductuum, F. chlamydosporum, F. arthrosporioides, F. longipes, and F. tumidum, were encountered rarely, each being represented by a single isolate.