B–A translocations were utilized in Zea mays L. to assign regions affecting the fatty acid composition of embryo oil to chromosome arms. A region affecting all four measured fatty acids (palmitic, stearic, oleic, and linoleic acids) was assigned to the long arm of chromosome 4 by results of tests with TB-4Lb, whereas another affecting palmitic and stearic acids was assigned to the long arm of chromosome 10 by tests with TB-10L19. These effects were in agreement with previous results from analysis of trisomy for chromosome 4 and monosomy for chromosome 10. The fatty acid composition of euploid embryos containing a B chromosome was not significantly different from that of embryos not containing a B chromosome. Thus, the B chromosome is not responsible for the differences observed using B–A translocations. TB-5La was backcrossed into two inbred lines having a relatively high percentage of linoleic acid. Hyperploidy for the long arm of chromosome 5 significantly increased the percentage of linoleic acid in both inbreds. Aneuploidy for the long arm of chromosome 5 also had a dosage effect on fatty acid composition of the endosperm.Key words: Zea, corn oil, fatty acids, B chromosome, translocation.
Genetic analysis of oleic acid content in the oils of maize sugary-2 mutants
