Transgene escape: what potential for crop-wild hybridization?

Area of Science:

• Agricultural Science
• Ecology
• Genetics

Background:

• Regional surveys for transgene escape from genetically modified (GM) crops often rely on spontaneous hybridization records.
• Such records are scarce for many plant species, especially outside Europe.
• Assessing interspecific reproductive compatibility through experimental crosses offers a valuable alternative, particularly when field data are limited.

Purpose of the Study:

• To evaluate the potential for transgene escape via hybridization in New Zealand.
• To assess reproductive compatibility between 123 temperate crops and their indigenous/naturalized relatives in New Zealand.
• To establish a risk assessment framework for GM crop transgene flow where spontaneous hybridization data is lacking.

Main Methods:

• Conducted experimental crosses between 123 widely grown temperate crops and their indigenous and naturalized relatives in New Zealand.
• Assessed interspecific reproductive compatibility as a proxy for potential transgene escape.
• Analyzed data to categorize crops based on reproductive compatibility with wild relatives.

Main Results:

• 54% of assessed crops (66 out of 123) showed reproductive compatibility with at least one indigenous or naturalized species.
• An additional 10% of crops (12 out of 123) exhibited limited reproductive compatibility with wild relatives.
• 20% of crops (25 out of 123) were reproductively isolated from all wild relatives in New Zealand; data was insufficient for 16% (20 out of 123).

Conclusions:

• Experimental crosses are a crucial tool for assessing GM crop transgene escape risk, especially in regions with limited spontaneous hybridization data.
• A significant proportion of widely grown temperate crops in New Zealand possess the potential for hybridization with wild relatives.
• The methodology provides a framework applicable to other regions for evaluating crop-wild gene flow potential.