In the Pacific Northwest, one herbicide resistant wheat is currently undergoing field testing. A major concern with this approach is whether the potential exists for the herbicide resistance to be transferred into the goatgrass. To determine if resistance could be transferred, information on the genetics of both jointed goatgrass and the natural hybrids that occur between wheat and goatgrass is needed. Genetics of Jointed Goatgrass Jointed goatgrass is an allotetraploid with 28 chromosomes. One reason goatgrass and wheat are so similar is that the two species share a common ancestor, the donor of the D genome.
Wheat also contains genomes from two other species, A and B, so it is an allohexaploid.
These hybrids are expected to be sterile because of the lack of chromosome pairing during meiosis except for the D genomes. The lack of pairing leads to unbalanced chromosome numbers in the gametes and this is considered the cause of the sterility. It was surprising therefore to find viable seed on several jointed goatgrass X wheat hybrids in 1990. Figure 1 . Results of a hybrid between jointed goatgrass and wheat.