The allotetraploidization of maize

Summary Allotetraploidization is the creation of artificial allotetraploids. Allotetraploidization of maize can be achieved by restructuring a maize genome so that its chromosomes will not pair with those of the normal maize genome. The restructuring can be done by concentrating induced or naturally occurring visible and cryptic chromosome aberrations and qualitatively different genetic material into a single line by a recurrent selection type of breeding program. The basis of allotetraploidization is the presence of differential pairing affinity between normal and restructured chromosomes. Experiments demonstrate that differential pairing affinity factors occur naturally in exotic races and in standard corn belt inbred lines and that they may be readily induced by X-irradiation and chemical mutagens.Contribution from the Science and Education Administration, U.S. Department of Agriculture, and the Agronomy Department, University of Missouri, Columbia, Missouri, Missouri Agric. Exp. Sta. Journal Series No. 8092