Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



As previously reported, true-breeding diploid mutant plants arise for colchicine treatment of sorghum seedlings of lines Experimental 1 and Experimental 3. It was hypothesized that such mutants may result from point mutations made homozygous by a somatic reduction of the chromosomes followed by doubling in a cell which organized a new growing point after inactivation of the original by colchicine. The first part of this study was an attempt to test this hypothesis by treating with colchicine sorghum seedlings containing a reciprocal translocation in the heterozygous condition which serves as a chromosome marker to indicate whether chromosomal homozygosity was induced. This translocation was not available in the genotype known to give homozygous mutants after colchicine treatment. In the second part of the study, an investigation was carried out to define reciprocal translocation lines which had been induced by radiation with cobalt 60 in Experimental 3 which has repeatedly given homozygous mutants after colchicine treatment. The third part of this study was a continuation of an investigation of the effects of cobalt 60 on Experimental 3 begun by Hubert Haensel designed to obtain additional gene markers in Experimental 3. Third generation populations from radiated Experimental 3 plants were obtained.

Library of Congress Subject Headings



Includes bibliographical references



Number of Pages



South Dakota State University