SOME RELATIONS OF FUSARIUM LINI AND POTASSIUM CYANIDE

Abstract

Since there is in the young flax plant a characteristic glucoside, linamarin, which splits into hydrocyanic acid and glucose, it seemed worth while to determine the reaction of Fusarium lini, the pathogen of the flax-wilt disease, toward several cyanogen compounds. The well known action of potassium cyanide on animals suggested that it would be well to test its effects upon the fungus. As early as I875 it was shown (i) that hydrogen cyanide destroys the vitality of yeast, but little work seems to have been done in studying its relations to other fungi. Stevens (2) reported upon some work and called attention to the comparatively innocuous character of potassium cyanide in killing fungous spores. The splitting of several glucosides by enzymic action, including some cyanogenetic glucosides, has been described (3) for a few of the molds, especially the genus Aspergillus. The immediate objectives in the experimental work here reported were to test the toxic effects of potassium cyanide upon Fusarium lini and to determine any possible stimulation of growth caused by it. The cultures were made in petri dishes, the synthetic agar culture having been treated with varying strengths of potassium cyanide. These were then inoculated with Fusarium lini in the center of each dish. A volume-molecular solution of KCN was made and diluted to the following strengths in the culture medium: I/IOOO M; 5/IOOO M; I/IOO M; 2/IOO M; 3/IOO M; and so forth to I/IO M. The record of growth was kept by measuring in millimeters the total diameter of the colony resulting from the inoculation in the center. The results are given in table i, taking the average diameter of three cultures for each concentration, except in the cases indicated by stars, where only two are averaged. TABLE I. Figures Indicate Diameters in mm.