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Potato clone variation in blackspot susceptibility, extract darkening, and some chemical factors




Thornton, Michael Kent, author
Workman, Milton, advisor

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Six potato clones were analyzed with respect to tissue extract darkening, phenolic content, dry matter, and potassium content to determine if these properties were related to differences in blackspot susceptibility. Clones differed significantly in tissue extract darkening, dry matter and potassium content, but not phenolic content. Differences in tissue extract darkening were not significant when cell wall fragments were filtered. The potential of the tissue to darken, as determined by tissue extract darkening studies, was not consistently related to blackspot susceptibility. Clones with low tissue extract darkening darkened most in response to addition of substrate (catechol). Phenolic content (tyrosine and o-diphenols) were more consistently related to tissue extract darkening than to blackspot susceptibility. Dry matter content was most closely related to blackspot susceptibility, but did not account for all differences. Potassium content was not related to blackspot susceptibility. Changes in ascorbic acid content of bruised and nonbruised tissue of four potato clones were followed over time to determine if they were related to blackspot susceptibility. Ascorbic acid content of bruised and nonbruised tissue of three clones decreased over 24 hours. However, the ascorbic acid content of one clone increased during this same period. These changes were not related to blackspot susceptibility. Differences in ascorbic acid content between bruised and nonbruised tissue of the same tuber were significant in 3 of 4 clones but were not related to blackspot susceptibility.


1983 Fall..
Covers not scanned.
Includes bibliographical references.

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Potatoes -- Diseases and pests
Plants -- Analysis


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