Figure 5: Wheat growing regions of Australia. 5a: T. turgidum cultivation areas in Australia (AEGIC 2014); 5b: Australian wheat growing areas with predicted yields for 2015 (AEGIC 2015).
Hybridisation between wheat and barley (H. vulgare) has not been recorded under natural conditions. A maximum frequency of pollen-mediated gene flow of 0.005 % was observed between wheat and barley over a distance of 10 m under field conditions in South Australia (Gatford et al. 2006). Only one case of natural hybridisation between wheat and the weedy species H. marinum has been reported (see Guadagnuolo et al. 2001). The authors suggest that this is a rare event but nonetheless recommend a 20 to 30 m isolation distance between GM wheat field and H. marinum. H. marinum has been observed in the Australian wheatbelt area, more specifically in NSW, Vic., SA and WA (Simon & Alfonso 2014).
Other members of the Triticeae tribe have been described in Australia. Their distribution, potential weediness and the existence of hybrids with wheat are detailed in Table 8.
Table 8: Non-cultivated Triticeae genera in Australia: distribution, weediness, and known hybrids with wheat.