Abstract of Dissertation Presented to the Graduate School 

 of the University of Florida in Partial Fulfillment of the 

 Requirements for the Degree of Doctor of Philosophy 



CYTOLOGICAL METHODS FOR THE DETECTION, 



IDENTIFICATION, AND CHARACTERIZATION OF ORCHID 



VIRUSES AND THEIR INCLUSION BODIES 



By 



Nan-Jing Ko 



May 19 85 



Chairman: F. W. Zettler 

 Cochairman: J. R. Edwardson 

 Major Department: Plant Pathology 



Light microscopy was explored for detecting and diagnosing 



orchid viruses. Bioassay, serology and electron microscopy 



have all been used for viral detection, but most studies have 



involved only Cymbidium mosaic and Odontoglossum ringspot 



viruses. The other orchid viruses are not well-characterized 



and practical means for their diagnoses in orchids have not 



been developed. In this investigation, light microscopic 



techniques were developed and their diagnostic potential was 



assessed. Calcomine orange-Luxol brilliant green ( 0/G ) 



combination and Azure A were used for selective staining of 



proteinaceous inclusions and inclusions containing 



nucleoprotein , respectively. Six viruses were studied, 



Cymbidium mosaic (CyMV), Odontoglossum ringspot (ORSV), bean 



yellow mosaic (BYMV), cucumber mosaic (CMV), and two 



uncharacterized bacilliform viruses. Other techniques were 



used to verify the light microscopic results. These included 



vi 



