Decision document DD2024-147: Determination of the safety of Albaugh, LLC's AXigen wheat (Triticum aestivum L.) developed through chemical mutagenesis

Authorized as of April 26, 2024

The Canadian Food Inspection Agency (CFIA) has evaluated information submitted by Albaugh, LLC concerning herbicide-tolerant AXigen wheat. This line was evaluated using the CFIA's streamlined process for herbicide tolerant plants that do not contain foreign DNA. The CFIA has determined that this plant with a novel trait (PNT) does not present altered environmental risk when compared to wheat varieties currently grown in Canada when a herbicide tolerance management plan is implemented. AXigen wheat is therefore authorized as of April 26, 2024, subject to the provisions outlined in this document.

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1. Identification of the modified plant

Designation or identifier: AXigen wheat

Applicant: Albaugh, LLC

Plant species: Wheat (Triticum aestivum L.)

Novel herbicide tolerance trait: Tolerance to quizalofop-p-ethyl herbicide. A cytosine-to-thymine mutation in the gene encoding the native Triticum aestivum acetyl coenzyme A carboxylase (taACCase) protein results in a change from alanine-to-valine at residue 2004 of the amino acid sequence of the taACCase protein. This change enables the plant to survive in the presence of quizalofop-p-ethyl herbicide.

Trait introduction method: Chemical mutagenesis using ethyl methanesulfonate

Intended end use: AXigen wheat is intended to be grown for human food use.

Intended area of cultivation: AXigen wheat is intended to be grown within the normal production area for wheat in Canada.

2. Criteria for evaluating the proposed environmental release

The CFIA has reviewed information provided by the applicant, as described in the Assessment Criteria for Determining Environmental Safety of Plants with Novel Traits. The CFIA has considered:

  • Potential for the herbicide-tolerant plant to become a weed of agriculture
    • More specifically: the changes in usual agronomic practices that may arise from the need to control volunteer plants with novel herbicide tolerances
  • Potential for gene flow from the herbicide-tolerant plant to sexually compatible plants whose hybrid offspring may become more weedy or more invasive
  • Potential impact of the herbicide-tolerant plant on biodiversity
    • More specifically: the potential that continued application of the same herbicide in subsequent rotations may lead to development of herbicide-tolerant weed populations

To address the following issues, the applicant submitted a herbicide tolerance management plan to the CFIA. The CFIA used information on the biology of wheat and information about the novel herbicide tolerance trait to evaluate the suitability of this herbicide tolerance management plan.

Potential for AXigen wheat to become a weed of agriculture

As indicated in BIO1999-01, The Biology of Triticum aestivum L. (Wheat), wheat possesses few of the characteristics that are common to weeds and invasive plants. It is an annual crop that does not persist in unmanaged ecosystems without human intervention. Wheat plants can grow as volunteers in cultivated fields in the seasons following a wheat crop, but they are usually eliminated by soil cultivation or the use of herbicides. There have been no reports of wheat becoming an unmanageable weed of agriculture or an invasive pest, in North America or elsewhere.

The CFIA considered the changes in usual agronomic practices for volunteer wheat in Canada that may arise from growing AXigen wheat. Plants of AXigen wheat growing as volunteers will not be controlled by quizalofop-p-ethyl herbicide. However, control of AXigen wheat as a volunteer weed in subsequent crops or in fallow ground can be achieved by the use of other classes of herbicides or by mechanical means.

The applicant's herbicide tolerance management plan includes adequate strategies to control AXigen wheat volunteers. These strategies include practices such as growing AXigen wheat in a multi-year rotation plan with other crops and using herbicides from different chemical classes to control AXigen wheat volunteers.

The CFIA has therefore concluded that AXigen wheat has no altered weediness potential in Canada compared to currently grown wheat varieties, when a herbicide tolerance management plan is implemented.

Potential for gene flow from AXigen wheat to sexually compatible plants whose hybrid offspring may become more weedy or more invasive

As indicated in BIO1999-01, The Biology of Triticum aestivum L. (Wheat), no known wild Triticum species exist in North America. The closest known relatives in North America are members of the Aegilops genus.

Aegilops cylindrica, jointed goatgrass, is present in the United States where it can be found as a weed in winter wheat fields. In Canada, jointed goatgrass is reported in Ontario and British Columbia where it is a regulated pest and a prohibited noxious weed (Canadian Food Inspection Agency, 2023). The incursions of jointed goatgrass in Canada are small, localized populations under Canadian Food Inspection Agency regulatory control. Some of these localized populations have been declared eradicated, while others are currently under eradication. Gene flow may occur between wheat and jointed goatgrass at a low rate, and a small percentage of gene flow events could result in viable hybrid offspring. It is the CFIA's opinion that the risk of gene flow between AXigen wheat and jointed goatgrass is minimal in Canada given the limited range of jointed goatgrass.

The only common weed species found in Canada that is closely related to wheat is Agropyron repens (quackgrass). Quackgrass is a troublesome weedy grass of agricultural areas throughout Canada. However, no known naturally-occurring hybrids between wheat and any Agropyron species have been reported and published literature indicates that natural crossing between these two genera is unlikely.

Other wild relatives of wheat occur in Canada, but it is improbable that hybrids between wheat and these relatives would occur in nature, for more information, see BIO1999-01, The Biology of Triticum aestivum L. (Wheat). Triticale is a crop that has been developed by humans by crossing wheat (Triticum aestivum or T. turgidum) with rye (Secale cereale). There have been no reports of triticale serving as a hybridization bridge between wheat and rye.

The CFIA has therefore determined that the likelihood of gene flow from AXigen wheat to wild or weedy species in Canada is negligible at this time. However, these conclusions may need to be revisited if jointed goatgrass becomes established.

Potential impact of AXigen wheat on biodiversity

The CFIA considered the potential that continued application of quizalofop-p-ethyl herbicide in subsequent crop rotations may lead to development of herbicide resistant weed populations.

The applicant's herbicide tolerance management plan for AXigen wheat contains adequate recommendations to minimize and manage the development of quizalofop-p-ethyl herbicide resistant weed populations. These recommendations include strategies such as avoiding the continuous use of quizalofop-p-ethyl herbicide and following recommended crop rotation practices.

The CFIA has therefore concluded that the potential impact on biodiversity of AXigen wheat is unlikely to be different from that of the wheat varieties that are currently grown in Canada, when a herbicide tolerance management plan is implemented.

3. New information requirements

If at any time, Albaugh, LLC becomes aware of any new information regarding risk to the environment or human health, which could result from the unconfined environmental release of AXigen wheat or lines derived from it, Albaugh, LLC is required to immediately provide such information to the CFIA. On the basis of such new information, the CFIA will re-evaluate the potential impact of AXigen wheat on the environment and may re-evaluate its decision with respect to the unconfined environmental release authorization of AXigen wheat.

4. Regulatory decision on environmental release

Based on the review of the information submitted by the applicant and input from other relevant scientific sources, the CFIA has concluded that the unconfined environmental release of AXigen wheat does not present altered environmental risk when compared to wheat varieties that are currently grown in Canada when a suitable herbicide tolerance management plan is implemented.

The applicant's herbicide tolerance management plan was determined to be satisfactory when evaluated by the CFIA. As outlined in the plan, the applicant will make this herbicide tolerance management plan readily available to growers and agronomists involved in the cultivation of AXigen wheat to promote careful management practices. The applicant will provide an efficient mechanism for growers to report agronomic problems to the company, which will facilitate the ongoing monitoring of AXigen wheat. The applicant will also monitor grower implementation to determine the effectiveness of the herbicide tolerance management plan and make any changes to the plan as appropriate.

Unconfined release into the environment of AXigen wheat is therefore authorized by the CFIA as of April 26, 2024.

Lines derived from the authorized line

Any wheat lines derived from AXigen wheat may also be released into the environment, provided that:

  • no inter-specific crosses are performed,
  • the intended uses are similar, and
  • it is known based on characterization that these plants do not display any additional novel traits and are substantially equivalent to wheat varieties that are currently grown in Canada, in terms of their potential environmental impact.

Cultivation of lines derived from AXigen wheat is subject to herbicide tolerance management requirements.

Other regulatory requirements

AXigen wheat is subject to the same phytosanitary import requirements as unmodified wheat varieties. AXigen wheat is required to meet the requirements of other Canadian legislation as applicable, including but not limited to, the Food and Drugs Act, the Feeds Act, and the Pest Control Products Act.

5. Contact us

For more information on this decision, please contact the CFIA's Plant Biosafety Office.