Environmental biosafety of field scale GM triticale (xTriticosecale Wittmack) cultivation for bioindustrial applications

• Author / Creator

  Kavanagh, Vanessa B

• Triticale (xTriticosecale Wittmack) is an intergeneric hybrid of wheat (Triticum aestivum L. and T. Durum Desf.) and rye (Secale cereale L.) that is primarily utilized as an animal feed crop, but is being genetically modified (GM) to take advantage of its bioindustrial qualities. Prior to release of GM triticale cultivars, the potential for pollen-mediated gene flow (PMGF) and adventitious presence (AP) needs to be assessed to determine if it can coexist with weedy relatives and conventional wheat and triticale without causing unacceptable market harm.
  We evaluated the potential for PMGF from triticale to wild and weedy relatives in Canada. In North America, triticale has few relatives with the exception of cereal crops wheat (spring and durum) and rye. Outside of parental genera, triticale is at highest risk for hybridization with intermediate wheatgrass (Agropyron intermedium (Host) Beauv.) and jointed goatgrass (Aegilops cylindrica Host).
  Small and large plot experiments were conducted to quantify intraspecific PMGF from a triticale with a blue aleurone dominant trait to another triticale cultivar and spring and durum wheat. Combining small and large plot data, average intraspecific PMGF from 0.2-1.4 m was 0.76%. Large plot experiments recorded an average 3.4% PMGF adjacent the BA donor that, following an exponential decay model, declined to 0.09% by 50 m. Directional differences were detected with highest PMGF corresponding to prevailing wind directions at flowering. The estimated AP of GM triticale after harvest blending within a 50 m conventional field was 0.22%.
  We quantified interspecific PMGF from triticale to wheat because triticale is compatible with spring and durum wheat, exhibits synchronous flowering and may be grown in proximity. In small plot experiments, PMGF ranged from 0.0008% for spring wheat to 0.0006% for durum wheat, well below international labeling thresholds. Data indicated interspecific hybrids were rare.
  Based on this research, intra- and interspecific PMGF may not prevent approved GM triticale from co-existing with weedy relatives and conventional triticale and wheat cultivars.

• Subjects / Keywords

  • Triticale
  • Gene flow
  • Interspecific outcrossing
  • Intraspecific outcrossing

• Graduation date

  Spring 2012

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3VK6R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.