A New Species of Hyalothyridium Associated with a Leaf Spot of Maize in Latin America

ABSTRACT

Hyalothyridium leaf spot of maize is prevalent in several Latin American countries, but has not been found in the United States. It occurs in humid areas at high and low altitudes, and can be severe during rainy seasons. Leaf spots range from small, tan, elliptical spots with brown borders to large almost circular brown blotches that enlarge up to 1.5 cm in diam, sometimes so numerous that most of the leaf surface is covered. In both types of lesions there are pycnidia bearing large, hyaline, dictyosporous conidia of a Hyalothyridium species in close association with similar bodies bearing spermatium-like cells that may be part of the life cycle. The history of the genus and its relationship to Camarosporium is discussed, and the maize fungus is described as a new species.

Key Words:

• maize leaf spot
• round blotch
• corn disease
• Hyalothyridium maydis
• Camarosporium