Patent ID: 6407311
Filing Date: 2002-06-18
Classification: A01H

Abstract:
A method for the maintenance of a male-sterile female parental line of common or durum wheat for use in the production of hybrid wheat, said method comprising:(a) crossing a female parent with a male parent, said female parent being a male-sterile plant homozygous both for any one of the recessive ms-B1 male-sterility alleles on the short arm of chromosome 4B (4BS), and for the dominant pollen-killer Ki-B1 allele on the long arm of chromosome 6B (6BL), said male parent being the maintainer line and being isogenic to the female parent and homozygous for the same ms-B1 and Ki-B1 alleles as the female parent, and having an additional alien engineered chromosome selected from: (i) an engineered chromosome, herein referred to as EC, consisting of segments derived from two or more different alien chromosomes, carrying a dominant male-fertility allele Ms, a recessive allele ki which is susceptible to the killing action of the native pollen-killer allele on 6BL and one or two selectable markers by which plants having this chromosome can be selected; and (ii) an improved engineered chromosome, herein referred to as IEC, consisting of segments derived from two or more different alien chromosomes carrying, in addition to the Ms, ki and the selectable marker alleles, a seed marker by which seeds having this chromosome can be separated from seeds not having it; and (b) harvesting from the cross of (a) the progeny seed, all of which are homozygous for said male-sterility and pollen-killer alleles and lack the engineered chromosome EC or IEC, said seeds, when grown, developing into said male-sterile female line.