The total number of viable bacteria found in Solanum tuberosum
stems and tubers was found to vary from less than 1 x 10³ to 4.7 x 10⁷ cells
per cm³ in stems and from 0 to 1.6 x 10⁴ cells per cm³ in tubers. About 75%
of both stems and tubers had populations at the lower end of the range but
there was no significant correlation between bacterial counts in stems and
tubers of the same plant. Bacteria found in potato tubers included species
of Micrococcus, Pseudomonas, Bacillus, Flavobacterium, Agrobacterium, and
Xanthomonas. Also present were coryneforms and some others which were not
identified to genus but were gram negative. Some of the coryneforms were
morphologically indistinguishable from the bacterial ring rot organism
(Corynebacterium sepedonicum) but non-pathogenic and biochemically different
from it. About 5% of stem smears of healthy plants showed more than 30
gram positive rods per microscope field.
All the Bacillus spp., one Pseudomonas sp. and three unidentified
species were found to inhibit C. sepedonicum in vitro. An antibiotic was
partially purified from the Bacillus sp. showing the greatest amount of
inhibition. This species was also antagonistic toward the following potato
pathogens: Pseudomonas solanacearum, Erwinia atroseptica, E. carotovora,
Alternaria solani, and Phytophthora infestans. Physical and chemical tests
showed that both a lipid and a peptide antibiotic were involved in the
antagonistic effect. / Land and Food Systems, Faculty of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/33643 |
| Date | January 1972 |
| Creators | De Boer, Solke Harmen |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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