VIEW ARTICLE

A Rapid Technique for Identifying the Clones of Fusarium oxysporum f. sp. lycopersici Causing Crown- and Root-rot of Tomato. L. E. Sanchez, Research Assistant, Department of Plant Pathology, University of California, Riverside 92502, Present address of senior author: Faculty of Agronomy, University of Chile, Santiago, Chile; R. M. Endo(2), and J. V. Leary(3). (2)(3)Professor, and Assistant Professor, respectively, Department of Plant Pathology, University of California, Riverside 92502. Phytopathology 65:726-727. DOI: 10.1094/Phyto-65-726.

A petri-plate technique has been developed that will distinguish the race of Fusarium oxysporum f. sp. lycopersici which causes crown- and root-rot of tomato from those that cause wilt. Isolates of the crown- and root-rot race caused a dark-brown, crown-girdling lesion on seedlings following inoculation of seeds placed on water agar containing either 0.5 ml of Schizophyllum minimal media or propylene-oxide treated carnation leaves. In contrast, the Fusarium wilt fungus produced a light-brown discoloration of the entire primary root. These same differences were manifested whether stem pieces from infected tomato plants or spore suspensions from pure cultures of each fungus were used as a source of inoculum.