TRANSFER OF A GENE FOR STEM RUST RESISTANCE FROM Aegilops caudata TO COMMON WHEAT

Abstract

A gene for stem rust resistance from Aegilops caudata was successfully incorporated into the genome of common wheat using the chromosome 5B method to promote homoeologous pairing. Following the initial cross of Ae. caudata with a monosomic 5B hexaploid plant, F₁ plants that were resistant in the seedling stage were subsequently backcrossed eight times to hexaploid wheat. The gene was highly effective at the seedling but not at the adult-plant stage. Stem-rust-resistant selections derived from similar crosses with Ae. triuncialis were shown to be either chromosome substitution or addition lines.Key words: Aegilops caudata, Triticum aestivum, stem rust resistance, interspecific transfer