Tropical rust is a fungal disease caused by the pathogen Physopella zeae (Mains) Cummins & Ramachar (syn. Angiopsora zeae Mains), previously classified as Angiopsora zeae Mains (Donald G. White, ed. 1999. Compendium of corn diseases. Third edition. APS Press, ISBN 0-89054-234-1). Tropical rust can spread very rapidly, killing the plant in a short time.
Disease management strategies include crop rotation, destruction of old maize residues by tillage, and fungicide application, all of which are aimed at reducing the fungal inoculum. However, the most effective and most preferred method of control for tropical rust is the planting of resistant hybrids.
The methods of controlling tropical rust by reducing fungal inoculum require additional time and resources on the part of the farmer, and in addition, can have detrimental effects on the environment. This makes the planting of resistant hybrids even more attractive to farmers and the general public. Thus, it is desirable to provide compositions and methods for identifying and selecting maize plants with enhanced resistance to tropical rust.