Characterization of Fusarium isolates from gladiolus corms pathogenic to pines.
Viljoen A., Wingfield M. J., Marasas W. F. O., Coutinho T. A.
Author Affiliation: Department of Microbiology and Biochemistry, University of the Orange Free Station, P.O. Box 339, Bloemfontein 9300, South Africa.
Plant Disease 79 : 1240-1244
Abstract : Fusarium subglutinans [Gibberella fujikuroi var. subglutinans] is a well-known pathogen of many crops. The fungus causes a serious disease of pines known as pitch canker. A proposal had been made to designate isolates from pines as F. subglutinans f.sp. pini. A problem regarding the nomenclature was that some F. subglutinans f.sp. pini isolates had been reported to induce decay of Gladiolus corms whereas certain isolates of F. subglutinans from Gladiolus corms were also found to be weakly to moderately pathogenic to Pinus sp. seedlings. In this study 3 previously studied isolates from Gladiolus in the USA that had been referred to as F. subglutinans or F. moniliforme [Gibberella fujikuroi] in the literature, were re-examined. These isolates were typical of F. proliferatum. They were mildly pathogenic on Pinus patula seedlings and significantly less virulent than an isolate of F. subglutinans f.sp. pini. Inoculation of Gladiolus corms with these isolates of F. proliferatum from Gladiolus, F. oxysporum from P. patula seedlings and F. subglutinans from P. patula, maize, mango and pineapple indicated that only isolates of F. proliferatum were moderately pathogenic to Gladiolus corms. It is concluded that this study supported the proposal that isolates of F. subglutinans [Gibberella fujikuroi var. subglutinans] from Pinus sp. represent a specific forma specialis within the species.