VIEW ARTICLE

Alteration of Sugar Translocation in Aspen by Hypoxylon mammatum. Arthur L. Schipper, Jr., Plant Physiologist, North Central Forest Experiment Station, USDA Forest Service, Folwell Avenue, St. Paul, Minnesota 55101; Gerald W. Anderson, Principal Plant Pathologist, North Central Forest Experiment Station, USDA Forest Service, Folwell Avenue, St. Paul, Minnesota 55101, The Station is maintained in cooperation with the University of Minnesota. Phytopathology 61:366-368. Accepted for publication 26 October 1970. DOI: 10.1094/Phyto-61-366.

Hypoxylon mammatum causes sugars to be accumulated above and below cankers on aspen (Populus tremuloides). These accumulated sugars are found in the xylem but not the phloem, and in highest concentration in xylem most recently invaded by the fungus. Use of radioisotope-labeled glucose showed that the fungus is able to inhibit sugar translocation at a distance from parasitized tissue. Since the xylem beneath the canker is plugged, it serves as storage tissue for the accumulated sugar. The hypothesis is advanced that this accumulated sugar is utilized by the fungus to support its growth vertically in the xylem and also into the bark.