Corn reddening: The disease and breeding for resistance

Abstract

Corn reddening (CR), observed for the first time in Serbia in 1957, has occurred sporadically there ever since, especially in the Banat area. However, in 2002 and 2003 severe outbreaks took place in late July-early August. Initial symptoms of CR consist in the apperance of a red-violet color on the leaves, leaf sheaths, husks and the bare portion of the internodes. Discolourations typically appear at the milk maturity stage, being strongest on top leaves, around the mid-rib and along the edges of the leaf blade, from base to tip. The ears are underdeveloped and kernels are shrivelled. Soon after symptom development, affected plants wilt, the foliage dessicates rapidly, most of the red pigmentation disappears, and affected plants eventually die. Controversy on the biotic or abiotic nature of CR seems to have been settled by the recent discovery of a possible phytoplasma aetiology. Whatever the cause, an interesting source of apparent resistance to CR was identified in a local maize population which may be used in breeding programmes.