VIEW ARTICLE

Techniques

Fluorescence Microscopy of Rapeseeds Invaded by Fungi. J. Schans, Graduate student, Agriculture Canada Research Station, 195 Dafoe Road, Winnipeg, Manitoba R3T 2M9; J. T. Mills(2), and L. Van Caeseele(3). (2)Senior research scientists, Agriculture Canada Research Station, 195 Dafoe Road, Winnipeg, Manitoba R3T 2M9; (3)Associate professor, Department of Botany, University of Manitoba, Winnipeg, Manitoba R3T 2N2. Phytopathology 72:1582-1586. Accepted for publication 4 May 1982. Copyright 1982 Department of Agriculture, Government of Canada.. DOI: 10.1094/Phyto-72-1582.

A modified acridine orange staining procedure was developed for examining sections of infected rapeseeds by fluorescence microscopy. Differentiation between seed and fungal structures was improved by prestaining with either malachite or methyl green to quench excessive fluorescence. These procedures permitted a comparison of growth and invasion patterns of Aspergillus amstelodami, Penicillium verrucosum var. cyclopium, and Verticillium lecanii into seeds of Brassica campestris ‘Candle.’ Variation in seed structure, such as heavy mucilage deposition, was also visualized by the modified acridine orange method. These differences in seed structure appeared to affect the timing of fungal penetration. Mycelial growth on the seed surface was most clearly differentiated by using ethidium bromide.