Use of herbicide resistant wheat as part of a weed control management strategy offers the best potential for controlling jointed goatgrass in winter wheat fields. To address the concern of migration of this resistance from wheat to jointed goatgrass, it has been proposed that the resistance gene be placed on either the A or B genome of wheat since these genomes are not shared between the two species. In studies using a resistance gene for glyphosate on either the A, B or D genomes, higher than expected rates of retention have been observed in backcrosses where jointed goatgrass was the recurrent parent. To determine if homozygosity was the reason for the high retention rate, 14 BC₂S₁ populations with herbicide resistance from the B genome were screened. In all cases the populations segregated 3:1, indicating the BC₂ plants were heterozygous. This would be the expected ratio of a gene being carried as a single copy in a wheat by wheat genetic background. The 3:1 ratio was surprising in this study where the BC₂ plants have an unstable genetic makeup of both wheat and jointed goatgrass chromosomes. A 3:1 ratio indicates that either pollen transmission was occurring with the wheat univalent carrying the resistance gene or there were multiple independent genes for the resistance trait. Reciprocal crosses were made between jointed goatgrass and the resistant lines to determine the rate of pollen transmission. The implications of pollen transmission and potential for gene flow among jointed goatgrass populations will be discussed.