Potential Hybridization of Genetically Engineered Triticale with Wild and Weedy Relatives in Canada

Triticale (xTriticosecale Wittmack) is a promising cereal platform for novel bioindustrial products being developed using genetic engineering (GE). Before GE crop varieties are approved in Canada, the potential for gene flow to wild and weedy relatives must be examined. To identify at-risk species for hybridization and gene flow, we reviewed the phylogeny of triticale relatives, outcrossing barriers, reported crosses, and occurrence of wild relatives in Canada. Presence of genes that inhibit outcrossing, genome constitution, geographic distribution, and floral structure influence triticale hybridization potential. Hybridization experiments between triticale and parental species indicate crosses may produce viable seeds, although outcrossing with rye (Secale cereale L.) is less likely. With respect to nonparental species that occur in Canada, jointed goatgrass (Aegilops cylindrica Host) and intermediate wheatgrass (Agropyron intermedium (Host) Beauv.) should be investigated to determine if viable hybrids with triticale can occur. While there are reports of wheat (Triticum spp.) hybridization with pubescent wheatgrass [Agropyron trichophorum (Link) K. Richt.], quackgrass [Elymus repens (L.) Gould], barley (Hordeum vulgare L.), and lyme grass (Leymus arenarius Hochst), hybridization with triticale under natural conditions seem unlikely.