Genetic Variation in Mycosphaerella Musicola Leach (Cercospora Musae Zimm.)

Abstract

Although Cercospora leaf spot (Sigatoka disease) of bananas has been known for nearly half a century, little is known of the genetics and variability of the pathogen, Mycosphaerella musicola Leach (Cercospora musae Zimm.). Most of our present knowledge concerning the organism has been derived from field observations and inoculation studies. Simmonds (10) believed that flask-shaped bodies of closely interwoven layers of hyphae surrounding a central mass of loose, hyphal cells in field-collected Sigatoka lesions were immature spermagonia or ascocarps. A direct relationship between the Cercospora musae (imperfect) stage and spermagonia was found by Stahel (11). Leach (7) later found numerous mature ascocarps always associated with numerous spermagonia and few conidial fructifications in field-collected Sigatoka lesions. However, lesions which had numerous conidial fructifications had few spermagonia and perithecia.