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Fitness of double vs. single herbicide–resistant canola

  • Marie-Josée Simard (a1), Anne Légère (a1), Ginette Séguin-Swartz (a2), Harikumar Nair (a2) and Suzanne Warwick (a3)...

Since 1995, canola cultivars with herbicide resistance (HR) have been readily adopted by Canadian producers. Gene flow between these cultivars with different HR traits has led to the occurrence of double herbicide–resistant (2HR) volunteers. To evaluate the fitness of canola volunteers with double HR, we compared three 2HR combinations to each of their parent single-HR plants (1HR: glufosinate-R, imidazolinone-R, glyphosate-R) commercial canola lines in separate greenhouse experiments. The replacement series design included five ratios of 2HR vs. 1HR plants at a single density of 129 plants m−2 and three stress treatments: herbicide application with either glufosinate, imazethapyr, or glyphosate; competition with a wheat crop; and a control without herbicide or wheat competition. Fitness indicators included aboveground biomass at 5 and 12 to 16 wk, seed production, and reproductive allocation. The 2HR plants showed delayed reproductive growth but were generally as competitive as 1HR commercial lines. Plant biomass of 2HR canola was comparable to or greater than 1HR canola, whereas seed biomass of 2HR canola was less than that of 1HR canola in half of the cases, likely because of delayed reproductive growth and early harvesting. Glufosinate–glyphosate 2HR was the fittest combination. Herbicide application had little effect on 2HR biomass at harvest, except for imazethapyr, which reduced the biomass and seed production of 2HR plants with imidazolinone-glyphosate resistance by 30%. The latter effect could have been from the unsuspected presence of 2HR plants with only one of the two acetolactate synthase mutations conferring resistance to imidazolinones. Wheat competition reduced fitness values of both 2HR and 1HR canola similarly, but seed production was still 64% that of the controls. Overall, there was little indication of reduced fitness in 2HR canola compared with commercial 1HR varieties.

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L. W. Aarssen 1985. Interpretation of the evolutionary consequences of competition in plants: an experimental approach. Oikos 45:99109.

H. J. Beckie , S. I. Warwick , H. Nair , and G. Séguin-Swartz 2003. Gene flow in commercial fields of herbicide-resistant canola (Brassica napus). Ecol. Appl 13:12761294.

R. E. Blackshaw , D. Kanashiro , M. M. Moloney , and W. L. Crosby 1994. Growth, yield and quality of canola expressing resistance to acetolactate synthase inhibiting herbicides. Can. J. Plant Sci 74:745751.

J. K. Conner and L. A. Zangori 1998. Combined effects of water, nutrient, and UV-B stress on female fitness in Brassica (Brassicaceae). Am. J. Bot 85:925931.

J. Connoly 1986. On difficulties with replacement-series methodology in mixture experiments. J. Appl. Ecol 23:125137.

M. J. Crawley , S. L. Brown , R. S. Hails , D. D. Kohn , and M. Rees 2001. Transgenic crops in natural habitats. Nature 409:682683.

M. J. Crawley , R. S. Hails , M. Rees , D. Kohn , and J. Buxton 1993. Ecology of transgenic oilseed rape in natural habitats. Nature 363:620623.

J. L. Cuthbert and P. B. E. McVetty 2001. Plot-to-plot, row-to-row and plant-to-plant outcrossing studies in oilseed rape. Can. J. Plant Sci 81:657664.

L. G. Firbank and A. R. Watkinson 1985. On the analysis of competition within two-species mixtures of plants. J. Appl. Ecol 22:503517.

A. Fitter , L. Williamson , B. Linkohr , and O. Leyser 2002. Root system architecture determines fitness in an Arabidopsis mutant in competition for immobile phosphate ions but not for nitrate ions. Proc. R. Soc. Lond., B 269:20172022.

J. R. Fredshavn and G. S. Poulsen 1996. Growth behavior and competitive ability of transgenic crops. Field Crops Res 45:1118.

L. F. Friesen , A. G. Nelson , and R. C. Van Acker 2003. Evidence of contamination of pedigreed canola (Brassica napus) seedlots in western Canada with genetically engineered herbicide resistance traits. Agron. J 95:13421347.

M. Fuchs , E. M. Chirco , J. M. McFerson , and D. Gonsalves 2004. Comparative fitness of a wild squash species and three generations of hybrids between wild × virus-resistant transgenic squash. Environ. Biosaf. Res 3:1728.

G. Guéritaine , M. Sester , F. Eber , A. M. Chèvre , and H. Darmency 2002. Fitness of backcross six of hybrids between transgenic oilseed rape (Brassica napus) and wild radish (Raphanus raphanistrum). Mol. Ecol 11:14191426.

J. Gressel and G. Ben-Sinai 1985. Low intraspecific competition fitness in a triazine-resistant, nearly nuclear-isogenic line of Brassica napus . Plant Sci 38:2932.

L. Hall , K. Topinka , J. Huffman , L. Davis , and A. Good 2000. Pollen flow between herbicide-resistant Brassica napus is the cause of multiple-resistant B. napus volunteers. Weed Sci 48:688694.

A. Kumar , G. Rakow , and R. K. Downey 1998. Isogenic analysis of glufosinate-ammonium tolerant and susceptible summer rape lines. Can. J. Plant Sci 78:401408.

P. Mason , L. Braun , S. I. Warwick , B. Zhu , and C. N. Stewart Jr. 2003. Transgenic Bt-producing Brassica napus: Plutella xylostella selection pressure and fitness of weedy relatives. Environ. Biosaf. Res 2:263276.

P. L. J. Metz , E. Jacobsen , and W. J. Stiekema 1997. Occasional loss of expression of phosphinothricin tolerance in sexual offspring of transgenic oilseed rape (Brassica napus L). Euphytica 98:189196.

K. W. Park , C. A. Mallory-Smith , D. A. Ball , and G. W. Mueller-Warrant 2004. Ecological fitness of acetolactate synthase inhibitor-resistant and -susceptible downy brome (Bromus tectorum) biotypes. Weed Sci 52:768773.

G. Rakow and D. Woods 1987. Out-crossing in rape and mustard under Saskatchewan prairie conditions. Can. J. Plant Sci 67:147151.

P. J. Regal 1988. The adaptive potential of genetically engineered organisms in nature. Trends Ecol. Evol 3:S36S38.

P. J. Regal 1994. Scientific principles for ecologically based risk assessment of transgenic organisms. Mol. Ecol 3:513.

M. A. Rieger , M. Lamond , C. Preston , S. B. Powles , and R. T. Roush 2002. Pollen-mediated movement of herbicide resistance between commercial canola fields. Science 296:23862388.

M. A. Sanderson and G. F. Elwinger 1999. Grass species and cultivar effects on establishment of grass-white clover mixtures. Agron. J 91:889897.

T. Sato 2004. Size-dependent sex allocation in hermaphroditic plants: the effects of resource pool and self-incompatibility. J. Theor. Biol 227:265275.

J. Schmitt and C. R. Linder 1994. Will escaped transgenes lead to ecological release? Mol. Ecol 3:7174.

I. J. Senior , C. Moyes , and P. J. Dale 2002. Herbicide sensitivity of transgenic multiple herbicide-tolerant oilseed rape. Pest Manag. Sci 58:405412.

M-J. Simard and A. Légère 2004. Synchrony of flowering between canola (Brassica napus) and wild radish (Raphanus raphanistrum). Weed Sci 52:905912.

A. A. Snow , B. Andersen , and R. B. Jørgensen 1999. Costs of transgenic herbicide resistance introgressed from Brassica napus into weedy B. rapa . Mol. Ecol 8:605615.

A. A. Snow , D. Pilson , L. H. Reisenberg , M. J. Paulsen , N. Pleskac , M. R. Reagon , D. E. Wolf , and S. M. Selbo 2003. A transgene reduces herbivory and enhances fecundity in wild sunflowers. Ecol. Appl 13:279286.

A. G. Stephenson 1981. Flower and fruit abortion: proximate causes and ultimate functions. Annu. Rev. Ecol. Syst 12:253269.

C. N. Stewart Jr, J. N. All , P. L. Raymer , and S. Ramachandran 1997. Increased fitness of transgenic insecticidal rapeseed under insect selection pressure. Mol. Ecol 6:773779.

S. Tan , R. R. Evans , M. L. Dahmer , B. K. Singh , and D. L. Shaner 2005. Imidazolinone-tolerant crops: history, current status, and future. Pest Manag. Sci 61:246254.

J. M. Tiedje , R. K. Colwell , Y. L. Grossman , R. E. Hodson , R. E. Lenski , R. N. Mack , and P. J. Regal 1989. The planned introduction of genetically engineered organisms: ecological considerations and recommendations. Ecology 70:298315.

A. M. Timmons , E. T. O'Brien , Y. M. Charters , S. J. Dubbels , and M. J. Wilkinson 1995. Assessing the risks of wind pollination from fields of genetically modified Brassica napus ssp. oleifera . Euphytica 85:417423.

A. Weigelt and P. Joliffe 2003. Indices of plant competition. J. Ecol 91:707720.

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