cultures were prepared by transferring a piece of tissue from the context of the fruit body to a potato dextrose agar (PDA) plate.
In diseased populations, 27 host individuals (one per family and dikaryon
type) were used as source of disease (see below), leaving 108 "target" plants.
Sporidia of opposite mating type must conjugate and form a dikaryon
before infecting the plant.
Spores dispersed to healthy flowers may germinate and undergo meiosis; a dikaryon
capable of infecting a plant is produced when meiotic products of opposite mating types conjugate (Baker 1947, Fischer and Holton 1957).
The recognition reaction of different products of these loci further leads to the formation of a dikaryon
that requires a maize host for further propagation (Kronstad and Staben, 1997).