Ten new defensins have been isolated from seeds of Triticum kiharae and related species of the Triticum and Aegilops genera by a combination of chromatographic procedures including affinity-, size-exclusion, and reversed-phase high-performance liquid chromatography. Nine were completely sequenced and shown to represent a family of closely related peptides with highly conserved amino acid sequences. Analysis of defensin compositions in diploid A-, B-, and D-genome donors to polyploid wheat allowed us for the first time to assign most defensin-encoding genes to particular hexaploid wheat genomes.