EDITOR'S NOTE

This text, when originally posted November 29, 2000, erroneously read:

In Canada, three cultivars of herbicide-tolerant canola have been approved and commercially introduced. However, the cultivars tolerant to Pursuit (imazethapyr) or Liberty (bromoxynil) were derived by herbicide selection procedures, not genetic engineering. Only the RR canola is transgenic. The risk of gene flow is similar for all three cultivars, yet no herbicide-resistant weedy relatives have been reported where these tolerant cultivars are grown.

In fact, four systems of herbicide-tolerant canola are in use in Canada, with many cultivars of each registered:

• Imidazoline tolerant (a.k.a. "Smart" system, or "Clearfield"); tolerant to Pursuit, Odyssey. Not transgenic but used biotech to select for the herbicide tolerance. Decision document with Canadian government explaining breeding and safety at http://www.cfia-acia.agr.ca/english/plaveg/pbo/dd9503e.shtml.
• Glyphosate tolerant (a.k.a. "Roundup Ready"); tolerant to Roundup. Transgenic method. Decision document: http://www.cfia-acia.agr.ca/english/plaveg/pbo/dd9502e.shtml.
• Glufosinate ammonium tolerant; tolerant to Liberty. Transgenic method. Decision document: http://www.cfia-acia.agr.ca/english/plaveg/pbo/dd9501e.shtml.
• Oxynil tolerant (a.k.a. "Navigator" system); tolerant to Compass, which is bromoxynil. Transgenic method. Decision document: http://www.cfia-acia.agr.ca/english/plaveg/pbo/dd9825e.shtml#A6. One gene from the bacteria Klebsiella pneumoniae subspecies ozanae has been introduced into the canola variety Westar, providing a field-level tolerance to oxynil herbicides. The gene codes for the bacterial enzyme nitrilase, which hydrolyzes ioxynil and bromoxynil into non-phytotoxic compounds.

AENews thanks Murray Hartman from the Government of Alberta, Canada, for this correction and additional information.