Determination of the Paternity of Wheat ( Triticum aestivum L) × Jointed Goatgrass ( Aegilops cylindrica Host) BC 1 Plants by Using Genomic In Situ Hybridization (GISH) Technique

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 BC 1 generation. Differences in the genomes of wheat (AABBDD) and jointed goatgrass (CCDD) could be used to determine the paternity of the BC 1 generation. Twenty BC 1 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 BC 1 paternity. Differences between the two BC 1 paternal types for number of C genome chromosomes indicates that C genome chromosome counts could be used to determine the paternity BC 1 plants providing a more accurate estimate of the potential for gene flow between the two species.