VIEW ARTICLE

Histology and Ultrastructure of Flax Crinkle. E. E. Banttari, Agricultural Experiment Station, University of Minnesota, St. Paul, Minnesota 55101; R. J. Zeyen, Agricultural Experiment Station, University of Minnesota, St. Paul, Minnesota 55101. Phytopathology 61:1249-1252. Accepted for publication 25 May 1971. DOI: 10.1094/Phyto-61-1249.

Leaves of flax infected with the oat blue dwarf virus developed enlarged lateral veins on which enations were formed. Indentations of the leaf surface occurred opposite the enations on the adaxial side of the leaves. This excessive proliferation of tissues resulted from hyperplasia of phloem elements and hyperplasia and hypertrophy of cells that normally develop into fibers and chloroplast-containing parenchyma. Parenchyma cells associated with enations either had small and abnormal chloroplasts or were devoid of them. Changes in vascular bundles in stems were slight, and consisted only of some hyperplasia of phloem and hyperplasia and hypertrophy of fibers. Occasional phloem elements, fibers, and intercellular spaces were occluded with a dark-staining substance. The virus was observed only in membrane-enclosed inclusions located along the inner walls of sieve elements, and was apparent as crystalline formations in some of these inclusions. Occasional membrane-bound inclusions were ruptured, and the virus was dispersed into the cell lumina. The virus particles were not inside, or associated with, cellular organelles.