Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2001
Publication Date: 5/20/2002
Citation: Zemetra, R.A., Wang, Z., Hansen, J., Hang, A., Mallory-Smith, C.A., Burton, C.S. 2002. Determination of the paternity of wheat (triticum aestivum l) x jointed goatgrass (aegilops cylindrica host) bc1, plants by using genomic in situ hybridization (gish) technique. Crop Science.
Interpretive Summary: Jointed goatgrass is a devastating weed in winter wheat fields of the western United States. It is closely related to wheat and can be potentially crossed each to wheat. If herbicide resistant wheat was released, the herbicide resistant gene could potentially move to jointed goatgrass by crossing and backcrossing. By using a genomic in situ hybridization technique, we have developed a method to characterize the frequency of the C genome (of goatgrass) being retained in the progenies of the first backcross, or BC1, between the two species. If the male parent in the BC1 is wheat, the frequency of the C genome is theoretically less. If the male parent in the BC1 is jointed goatgrass, the C genome could occur more often. This new method can be used to assess the potential for gene flow between the two species.
Technical Abstract: The release of herbicide resistant wheat (Triticum aestivum L.) raises concerns with gene flow between wheat and jointed goatgrass (Aegilops cylindrica Host). Hybrids between the two species and backcrosses with either species have been observed in the field. Gene flow is dependent on jointed goatgrass being the paternal parent of the BC1 generation. Differences in the genomes of wheat (AABBDD) and jointed goatgrass (CCDD) could be used to determine the paternity of the BC1 generation. Twenty BC1 plants (10 of each paternal type) were used to determine if the number of C genome chromosomes based on genomic in situ hybridization (GISH) could be used to determine BC1 paternity. Differences between the two BC1 paternal types for number of C genome chromosomes indicate that C genome chromosome counts could be used to determine the paternity BC1 plants providing a more accurate estimate of the potential for gene flow between the two species.