Seed transmission of Fusarium species and systemic infection in maize

Abstract

Fusarium species are ubiquitous and many times the strains used in an experiment are indistinguishable from those that already exist in the environment. This problem has made it necessary to use methods to "mark" strains. Vegetative compatibility, p-glucuronidase (GUS), and green fluorescent protein (GFP) are a few of the approaches used to mark fungal strains in order to study plant-pathogen interactions. All three methods have previously been used to study Fusarium species (Munkvold and Carlton 1997, Munkvold et al. 1997, Oren et al. 2001, Yates et al. 1999). These tools have facilitated detection and identification of different Fusarium strains in vitro and in planta. Vegetative compatibility can be utilized as a marker because clones of a strain are self-compatible. Vegetative compatibility is based on the ability of fungal strains to produce heterokaryons. Heterokaryon production between strains is controlled by vegetative incompatibility (vie) loci (Correll et al. 1987). Strains of the same species that successfully produce heterokaryons are placed in vegetative compatibility groups (VCGs) (Leslie 1993). Fungi that are incompatible cannot produce heterokaryons and may act antagonistically