VIEW ARTICLE

Cytology and Histology

Development of Cladosporium caryigenum in Pecan Leaves. A. J. Latham, Department of Plant Pathology and Botany, Alabama Agricultural Experiment Station, and College of Sciences and Mathematics, Auburn University, AL 36849; A. E. Rushing, Department of Microbiology, Alabama Agricultural Experiment Station, and College of Sciences and Mathematics, Auburn University, AL 36849. Phytopathology 78:1104-1108. Accepted for publication 29 March 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/Phyto-78-1104.

Conidia of Cladosporium caryigenum germinated on leaves of pecan (Carya illinoinensis) in the dark within 3 hr at 23 C and 100% relative humidity. After 12 hr, penetration of host cuticle was achieved by hyphae originating from appressoria. Subcuticular hyphae branched repeatedly, became wider, and grew over host anticlinal epidermal cell walls. Melanized bulbous cells on branches of subcuticular hyphae were observed at 144 hr. Conidiophores originating from these bulbous cells erupted through the cuticle. Conidia were first observed 168 hr after inoculation. Mycelium of C. caryigenum did not grow superficially on pecan leaves.