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Thesis (M.S.)—University of Nebraska—Lincoln, 1971. Department of Botany.


Copyright 1971, the author. Used by permission.


Isolation of a phytotoxin from the ring rot pathogen of potatoes, Corynebacterium sepedonicum, had previously been reported by Strobel (21). The first phase in our study was to investigate more extensively the general nature of this compound. The phytotoxin could possibly be a specific compound associated only with the ring rot pathogen. However, the possibility that the substance could be obtained from sources other than the bacterium had not been completely eliminated. In an attempt to answer this question, three extracts were purified and compared. First, compounds were isolated from a broth culture of bacteria in the manner described by Strobel (21). Second since the culture medium consisted of yeast extract, the possibility that similar types of compounds could be obtained from this medium was considered. Third, materials that possessed wilting activity were isolated from whole bacterial cells which had been subjected to sonic oscillation. Upon isolation of these three extracts, the physical properties and biological activity were compared to determine their degree of similarity.

An investigation was also made of the type of compound which was present in the extracts and capable of inducing biological activity. Preliminary work had shown the presence of nucleic acid in the extracts.

Advisor: Ellen M. Ball