Para-Fluorophenylalanine-induced chromosome number changes in higher plants. I. Maize

Abstract

Excised maize embryos and germinating maize seeds were treated with para-fluorophenylalanine to induce chromosome changes. Aneuploidy and changes in ploidy levels were observed. Identified hypoploid changes involved the loss of a single chromosome and, in one case, the loss of one arm of a chromosome. Hyperploids included trisomics, double trisomics, and probably tetrasomics. The use of karyotype analysis demonstrated that at least 6 of the 10 maize chrosssmosomes were involved in these modifications. Analysis of chromosome numbers in progeny indicated the "likely" chromosome number of the reproductive tissue of treated plants. In some treated plants the likely chromosome number of the reproductive tissue was the same as that observed in adventitious roots, while in others it was different from that of their adventitious roots. The use of para-fluorophenylalanine may be of value in plants other than maize for purposes of chromosome number engineering.Key words: aneuploids, chromosome number changes, maize, para-fluorophenylalanine, Zea mays.