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Thesis (M.S.)--University of Nebraska--Lincoln, 1953. Department of Agronomy.


Copyright 1953, the author. Used by permission.

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The development of a practical method of breedings corn through the utilization of homozygous lines obtained from the doubling of monoploids will depend upon the obtaining of a reasonably high rate of monoploids from any particular stock, representing desirable gametes for corn production, and on the successful doubling of such monoploids. This study is an investigation of various aspects of these problems.

Approximately one hundred twenty thousand individual plants representing the progenies of eighteen crosses of corn were examined for monoploid sporophytes. Monoploids were found to occur at a mean frequency of 0.82 per thousand seedlings screened. Significant differences in the frequency of the occurrence of monoploids were found. Delayed pollination and limited agronomic selection did not increase the frequency of monopolidy in the open-pollination variety, Krug, and its derivatives.

The monoploid method, as used in this study, was not found to be superior to the long-time selfing method now in use for the establishment of large numbers of inbred lines from previously untested material.