The biology and ecology of hexaploid wheat (Triticum aestivum L.) and its implications for trait confinement

Canadian Journal of Plant Science

Volumn 88, Issue 5, 2008, Pages 997-1013

  Willenborg, Christian J ^a   Van Acker, Rene C ^b  

^a UNIVERSITY OF MANITOBA   (Canada)

^b UNIVERSITY OF GUELPH   (Canada)

Author keywords

Coexistence; Gene flow; Genetically engineered; Herbicide resistant; Trait confinement; Triticum

Indexed keywords

AUTOGAMY; BIOLOGY; COEXISTENCE; ECOLOGY; FARMING SYSTEM; GENE FLOW; GERMINATION; HYBRIDIZATION; PERSISTENCE; PESTICIDE RESISTANCE; POPULATION DYNAMICS; RELATIVE ABUNDANCE; REPRODUCTIVE STRATEGY; TRANSGENIC PLANT; WHEAT;

SECALE CEREALE; TRITICUM; TRITICUM AESTIVUM; TRITICUM TURGIDUM;

EID: 56849115758     PISSN: 00084220     EISSN: None     Source Type: Journal    
DOI: 10.4141/CJPS07144     Document Type: Review

References (142)

1. Anderson, J. A., Matthiesen L. and Hegstad, J. 2004. Resistance to an imidazolinone herbicide is conferred by a gene on chromosome 6DL in the wheat line cv. 9804. Weed Sci. 52: 83-90.
2. Anderson, R. L. and Nielsen, D. C. 1996. Emergence pattern of five weeds in the central great plains. Weed Technol. 10: 744-749.
3. Anderson, R. L. and Soper, G. 2003. Review of volunteer wheat (Triticum aestivum) seedling emergence and seed longevity in the soil. Weed Technol. 17: 620-626.
4. Anonymous. 2005a. The biology and ecology of bread wheat (Triticum aestivum L.) in Australia. Australian Government. [Online] Available: http://www.ogtr.gov.au/pdf/ir/biologywheat.pdf [2008 Jan. 25].
5. Anonymous. 2005b. Regulations and procedures for pedigreed seed crop production. Circular 6-05. Canadian Seed Growers' Association. Ottawa, ON. [Online] Available: http://www.seedgrowers.ca/regulationsandforms/circular.asp? lang=e [2008 Jan. 25].
6. Anonymous. 2007. Guide to field crop protection. Manitoba Agriculture, Food, and Rural Initiatives. Winnipeg, MB. 386 pp.
7. Argyris, J., Van Sanford, D. and TeKrony, D. 2003. Fusarium graminearum infection during wheat seed development and its effect on seed quality. Crop Sci. 43: 1782-1788.
8. Augspurger, C. K. 1981. Reproductive synchrony of a tropical shrub: Experimental studies on the effects of pollinators and seed predators on Hybanthus prunifolius (Violaceae). Ecol. 62:775-788.
9. Augspurger, C. K. 1983. Phenology, flowering synchrony, and fruit set of six neotropical shrubs. Biotropica 15: 257-267.
10. Austin, R. B. and Jones, H. G. 1975. The physiology of wheat. Pages 20-73 in Plant Breeding Institute, Annual Report. Cambridge, UK.
11. Ayal, A. and Levy, A. A. 2005. Wheat domestication and dedomestication - What are the odds? Pages 167-174 in J. B. Gressel, ed. Crop ferality and volunteerism. CRC Press, Boca Raton, FL.
12. Baalbaki, R. Z., Zurayk, R. A., Bleik, M. M. and Talhouk, S. N. 1999. Germination and seedling development of drought tolerant and susceptible wheat under moisture stress. Seed Sci. Technol. 27: 291-302.
13. Badaeva, E. D., Amosova, A. V., Muravenko, O. V., Samatadze, T. E., Chikida, N. N., Zelenin, A. V., Friebe, B. and Gill, B. S. 2002. Genome differentiation in Aegilops. 3 Evolution of the D-genome cluster. Plant. Syst. Evol. 231: 163-190.
14. Baker, C. K., Gallagher, J. N. and Monteith, J. L. 1980. Daylength and leaf appearance in winter wheat. Plant Cell Environ. 3: 285-287.
15. Barnes, R. F. and Beard, J. B. 1992. Crop Science Society of America glossary of crop science terms. ASA, CSSA, and SSSA. Madison, WI. 37 pp.
16. Bauer, A., Frank, A. B. and Black, A. L. 1984. Estimation of spring wheat leaf growth rates from air temperature. Agron. J. 76: 829-835.
17. Beckie, H. 2001. Impact of herbicide resistant crops as weeds in Canada. Pages 135-142 in Proceedings of the Brighton Crop Protection Conference - Weeds, Brighton, UK.
18. Beckie, H. J., Harker, K. N., Hall, L. M., Warwick, S. I., Légère, A., Sikkema, P. H., Clayton, G. W., Thomas, A. G., Leeson, J. Y., Séguin-Swartz, G. and Simard, M. J. 2006. A decade of herbicide-resistant crops in Canada. Can. J. Plant Sci. 86: 1243-1264.
19. Bennett, M. D. 1972. Nuclear DNA content and minimum generation time in herbaceous plants. Proc. R. Soc. (Lond.) Ser. B. 181: 109-135.
20. Beres, B. L., Cárcamo, H. A. and Byers, J. R. 2007. Effect of wheat stem sawfly damage on yield and quality of Canadian spring wheat. J. Econ. Entomol. 100: 79-87.
21. Bitzer, M. J. and Patterson, F. L. 1967. Pollen dispersal and cross-pollination of soft red winter wheat (Triticum aestivum L.). Crop Sci. 7: 482-484.
22. Blackshaw, R. E., Harker, K. N., Clayton, G. W. and O'Donovan, J. T. 2006. Broadleaf herbicide effects on clethodim and Quizalofop-P efficacy on volunteer wheat (Triticum aestivum L.). Weed Technol. 20: 221-226.
23. Boyd, N. S. and Van Acker, R. C. 2003. The effects of depth and fluctuating soil moisture on the emergence of eight annual and six perennial plant species. Weed Sci. 51: 725-730.
24. Braun, H. J., Payne, T. S., Morgounov, A. I., van Ginkel, M. and Rajaram, S. 1998. The challenge: One billion tons of wheat by 2020. Pages 33-40 in A. E. Slinkard, ed. Proc. 9th Int. Genet. Symp. Vol. 1, Saskatoon, SK. Univ. Ext. Press, Saskatoon, SK.
25. Briggs, K. G., Kiplagat, O. K. and Johnson-Flanagan, A. M. 1999. Floret sterility and outcrossing in two spring wheat cultivars. Can. J. Plant Sci. 79: 321-328.
26. Brûlé-Babel, A. L., Willenborg, C. J., Friesen, L. F. and Van Acker, R. C. 2006. Modeling the influence of gene flow and selection pressure on the frequency of a transgenic herbicide-resistant trait in non-transgenic wheat and wheat volunteers. Crop Sci. 46: 1704-1710.
27. Bullied, W. J., Marginet, A. M. and Van Acker, R. C. 2003. Conventional- and conservation-tillage systems influence emergence periodicity of annual weed species in canola. Weed Sci. 51: 886-897.
28. Burger, J. C. and Ellstrand, N. C. 2005. Feral Rye - Evolutionary origins of a weed. Pages 175-192 in J. B. Gressel, ed. Crop ferality and volunteerism. CRC Press, Boca Raton, FL.
29. Campbell, A. B. and Czarnecki, E. 1987. Katepwa hard red spring wheat. Can. J. Plant Sci. 67: 229-230.
30. Campbell, C. A., Zentner, R. P., Gameda, S., Blomert, B. and Wall, D. D. 2002. Production of annual crops on the Canadian prairies: trends during 1976-1998. Can. J. Soil Sci. 82: 45-47.
31. Canadian Food Inspection Agency. 2007. Summary of confined research field trials. [Online] Available: http://www.inspection.gc.ca/english/ plaveg/bio/confine.shtml#sum [2008 Jan. 25].
32. Canadian Wheat Board. 2008. Canadian Wheat Board variety survey. [Online] Available: http://www.cwb.ca/public/en/farmers/surveys/variety/2008/ pdf/results.pdf [2008 Jan. 25].
33. Cao, W. and Moss, D. N. 1989. Temperature and daylength interaction on phyllochron in wheat and barley. Crop Sci. 29:1046-1048.
34. Clarke, J. M. 1985. Harvesting losses of spring wheat in windrower/combine and direct combine harvesting systems. Agron. J. 77: 13-17.
35. Conner, A. J., Glare, T. R. and Nap, J. 2003. The release of genetically-modified crops into the environment II: Overview of ecological risk assessment. Plant. J. 33: 19-46.
36. Demeke, T., Perry, D. J. and Scowcroft, W. R. 2006. Adventitious presence of GMOs: Scientific overview for Canadian Grains. Can. J. Plant Sci. 86: 1-23.
37. Derksen, D. A., Thomas, A. G., Lafond, G. P., Loeppky, H. A. and Swanton, C. J. 1994. Impact of agronomic practices on weed communities: fallow within tillage systems. Weed Sci. 42: 184-194.
38. De Corby, K. A., Van Acker, R. C., Brûlé-Babel, A. L. and Friesen, L. F. 2007. Emergence timing and recruitment of volunteer spring wheat. Weed Sci. 55: 60-69.
39. De Vries, A. Ph. 1971. Flowering biology of wheat, particularly in view of hybrid seed production - A review. Euphytica 20: 152-170.
40. De Vries, A. Ph. 1972. Some aspects of cross pollination in wheat (Triticum aestivum L.) 1. Pollen concentration in the field as influenced by variety, diurnal pattern, weather conditions, and level as compared to the height of the pollen donor. Euphytica 21: 185-203.
41. De Vries, A. Ph. 1973. Some aspects of cross pollination in wheat (Triticum aestivum L.) 2. Anther extrusion and ear and plant flowering pattern and duration. Euphytica 22: 445-456.
42. De Vries, A. Ph. 1974a. Some aspects of cross pollination in wheat (Triticum aestivum L.) 3. Anther length and number of pollen grains per anther. Euphytica 23: 11-19.
43. De Vries, A. Ph. 1974b. Some aspects of cross pollination in wheat (Triticum aestivum L.) 4. Seed-set on male-sterile plants as influenced by distance from the pollen source, pollinator: male-sterile ratio and width of the male-sterile strip. Euphytica 23: 601-622.
44. Donald, W. W. and Ogg, Jr., A. G. 1991. Biology and control of jointed goatgrass (Aegilops cylindrica), a review. Weed Technol. 5: 3-17.
45. Dowding, P. 1987. Wind pollination mechanisms and aerobiology. Int. Rev. Cytol. 107: 421-437.
46. D'Souza, V. L. 1970. Investigations concerning the suitability of wheat as a pollen-donor for cross-pollination by wind as compared to rye, Triticale, and Secalotricum. Z. Pflanzenzuecht. 63: 246-269.
47. Ellstrand, N. C. and Hoffman, C. A. 1990. Hybridization as an avenue of escape for engineered genes. BioScience 40: 438-442.
48. Ellstrand, N. C., Prentice, H. C. and Hancock, J. F. 1999. Gene flow and introgression from domesticated plants into their wild relatives. Ann. Rev. Ecol. Syst. 30: 539-563.
49. Falk, D. E. and Kasha, K. J. 1981. Comparison of the crossability of rye (Secale cereale) and Hordeum bulbosum onto wheat (Triticum aestivum). Can. J. Genet. Cytol. 23: 81-88.
50. FAOSTAT. 2006. Data collections - agricultural production. [Online] Available: http://faostat.fao.org/faostat/collections?subset= agriculture [2008 Jan. 25].
51. Feldman, M. 1976. Taxonomic classification and names of wild, primitive, cultivated, and modern cultivated wheats. Wheats. Pages 120-128 in N. W. Simmonds, ed. Evolution of crop plants. Longman, London, UK.
52. Gaines, T., Preston, C., Byrne, P., Henry, W. B. and Westra, P. 2007. Adventitious presence of herbicide resistant wheat in certified and farm-saved seed lots. Crop Sci. 47: 749-754.
53. Gatford, K. T., Zainuddin, B., Edlington, J., Lloyd, J., Qureshi, J. A., Brettell, R. and Fincher, G. B. 2006. Gene flow from transgenic wheat and barley under field conditions. Euphytica 151: 383-391.
54. Goodman, R. M. and Newell, N. 1985. Genetic engineering of plants for herbicide resistance: Status and prospects. Pages 47-53 in H. O. Halverson, D. Pramer, and M. Rogul, eds. Engineered organisms in the environment: Scientific issues. American Society Microbiology, Washington, DC.
55. Graf, R. J., Hucl, P., Smith, J. and Song, L. S. P. 1990. Oslo red spring wheat. Can. J. Plant Sci. 70: 299-302.
56. Gressel, J. B. 2005. Introduction - the challenges of ferality. Pages 1-7 in J. B. Gressel, ed. Crop ferality and volunteerism. CRC Press, Boca Raton, FL.
57. Gross, R. S. and Werner, P. A. 1983. Relationships among flowering phenology, insect visitors, and seed-set of individuals: experimental studies on four co-occurring species of goldenrod (Solidago: Compositae). Ecol. Monogr. 53: 95-117.
58. Gustafson, D. I., Horak, M. J., Rempel, C. B., Metz, S. G., Gigax, D. R. and Hucl, P. 2005. An empirical model for pollen-mediated gene flow in wheat. Crop Sci. 45: 1286-1294.
59. Hall, L., Topinka, K., Huffman J., Davis, L. and Allen, A. 2000. Pollen flow between herbicide-resistant Brassica napus is the cause of multiple-resistant B. napus volunteers. Weed Sci. 48: 688-694.
60. Hanson, B. D., Mallory-Smith, C. A., Price, W. J., Shafii, B., Thill, D. C. and Zemetra, R. S. 2005a. Interspecific hybridization: Potential for movement of herbicide resistance from wheat to jointed goatgrass. Weed Technol. 19: 674-682.
61. Hanson, B. D., Mallory-Smith, C. A., Shafii, B., Thill, D. C. and Zemetra, R. S. 2005b. Pollen mediated gene flow from blue aleurone wheat to other wheat cultivars. Crop Sci. 45: 1610-1617.
62. Harker, K. N., Clayton, G. W., Blackshaw, R. E., O'Donovan, J. T., Johnson, E. N., Gan, Y., Holm, F. A., Sapsford, K. L., Irvine, R. B., Van Acker, R. C. 2005. Glyphosate-resistant wheat persistence in western Canadian cropping systems. Weed Sci. 53: 846-859.
63. Hegde, S. G. and Waines, J. G. 2004. Hybridization and introgression between bread wheat and wild and weedy relatives in North America. Crop Sci. 44: 1145-1155.
64. Heroldová , M., Tkadlec, E., Bryja, J. and Zejda, J. 2008. Wheat or barley: Feeding preferences affect distribution of three rodent species in agricultural landscapes. Appl. Anim. Behav. Sci. 110: 354-362.
65. Hucl, P. 1996. Out-crossing rates for 10 Canadian spring wheat cultivars. Can. J. Plant Sci. 76: 423-427.
66. Hucl, P. and Matus-Cádiz, M. A. 2001. Isolation distances for minimizing out-crossing in spring wheat. Crop Sci. 41: 1348-1351.
67. Hucl, P. and Matus-Cádiz, M. A. 2002a. CDC EMDR-4, CDC EMDR-9, and CDC EMDR-14 spring wheats. Can. J. Plant Sci. 82: 411-413.
68. Hucl, P. and Matus-Cádiz, M. A. 2002b. Line 211 spring wheat. Can. J. Plant Sci. 82: 127-128.
69. Hucl, P. and Matus-Cádiz, M. A. 2002c. W98616, a white-seeded spring wheat with increased pre-harvest sprouting. Can. J. Plant Sci. 82: 129-131.
70. Hucl, P., Matus-Cádiz, M. A., Sahota, A. S., Middleton, A., Mooney, D. and Maruschak, J. L. 2004. Sources of off-types in pedigreed seed of common spring wheat. Can. J. Plant Sci. 84: 519-523.
71. Huygen, I., Veeman, M. and Lerohl, M. 2003. Cost implications of alternative GE tolerance levels: Non-genetically modified wheat in western Canada. AgBioForum 6: 169-177.
72. James, C. 2006. Preview: Global status of commercialized biotech/GM crops: 2006. ISAAA Briefs No. 35-'2006. ISAAA, Ithaca, NY.
73. Jensen, N. F. 1968. Results of a survey on isolation requirements for wheat. Ann. Wheat Newsl. 15: 26-28.
74. Johnson, V. A., Schmidt, J. W. and Mattern, P. J. 1967. Hybrid wheat in the United States. Qual. Plant. Mater. Veg. 14: 193-211.
75. Joppa, L. R., MacNeal, F. H. and Berg, M. A. 1968. Pollen production and pollen shedding of hard red spring wheat (Triticum aestivum L.) and durum (T. durum Desf.) wheats. Crop Sci. 8: 487-490.
76. Kershen, D. L. 2004. Legal liability issues in agricultural biotechnology. Crop Sci. 44: 456-463.
77. Khan, M. N., Heyne, E. G. and Arp, A. L. 1973. Pollen distribution and seedset on Triticum aestivum L. Crop Sci. 13: 223-226.
78. Kimber, G. and Sears, E. R. 1987. Evolution in the genus Triticum and the origin of cultivated wheat. Pages 154-164. in E. G. Heyne, ed. Wheat and wheat improvement. 2nd ed. Agron. Monogr. 13. ASA, CSSA, and SSSA. Madison, WI.
79. Komatsuzaki, M. and Endo, O. 1996. Volunteer wheat in upland fields. Weed Res. (Toyko) 41: 197-204.
80. Kremer, R. J. 1993. Management of weed seedbanks with microorganisms. Ecol. Appl. 3: 42-52.
81. Lafond, G. P. and Baker, R. J. 1986. Effects of temperature, moisture stress, and seed size on germination of nine spring wheat cultivars. Crop Sci. 26: 563-567.
82. Lafond, G. P. and Fowler, B. D. 1989. Soil temperature and water content, seeding depth, and simulated rainfall effect on winter wheat emergence. Agron. J. 81: 609-614.
83. Lamb, R. J., Tucker, J. R., Wise, I. L. and Smith, M. A. H. 2000. Trophic interaction between Sitodiplosis mosellana (Diptera: Cecidomyiidae) and spring wheat: Implications for yield and seed quality. Can. Entomol. 132: 607-625.
84. Lawrie, R. G., Matus-Cádiz, M. A. and Hucl, P. 2006. Estimating out-crossing rates in spring wheat cultivars using the contact method. Crop Sci. 46: 247-249.
85. Leeson, J. Y., Thomas, A. G., Andrews, T., Brown, K. and Van Acker, R. C. 2002a. 2002 Manitoba Weed Survey of Cereal, Oilseed, and Pulse Crops. Agriculture and Agri-Food Canada, Saskatoon, SK. Weed Survey Ser. Publ. 02-2. 141 pp.
86. Leeson, J. Y., Thomas, A. G. and Hall, L. M. 2002b. 2001 Alberta Weed Survey of Cereal, Oilseed, and Pulse Crops. Agriculture and Agri-Food Canada, Saskatoon, SK. Weed Survey Ser. Publ. 02-1. 263 pp.
87. Leeson, J. Y., Thomas, A. G., Hall, L. M., Brenzil, C. A., Andrews, T., Brown, K. R. and Van Acker, R. C. 2005. Prairie weed surveys of cereal, oilseed and pulse crops from the 1970s to the 2000s. Canada Saskatoon Research Centre Agriculture and Agri-Food Canada, Saskatoon, SK. Weed Survey Ser. Publication 05-1. 395 pp.
88. Leighty, C. E. and Sando, W. J. 1924. The blooming of wheat flowers. J. Agric. Res. 27: 231-244.
89. Leighty, C. E. and Sando, W. J. 1928. Natural and artificial hybrids of a Chinese wheat and rye. J. Hered. 19: 23-37.
90. Livers, R. W. 1964. Seed yields of field-grown male-sterile wheats subjected to wind-borne pollen. Page 72. in Agronomy Abstracts. ASA and CSSA, Madison, WI.
91. Lyon, D. J., Bussan, A. J., Evans, J. O., Mallory-Smith, C. A. and Peeper, T. F. 2002. Pest management implications of glyphosate-resistant wheat (Triticum aestivum) in the western United States. Weed Technol. 16: 680-690.
92. Maan, S. S. 1987. Interspecific and intergeneric hybridization in wheat. Pages 453-461 in E. G. Heyne, ed. Wheat and wheat improvement. 2nd ed. Agron. Monogr. 13. ASA, CSSA, and SSSA, Madison, WI.
93. Major, D. J. 1980. Environmental effects on flowering. Pages 1-15 in W. R. Fehr and H. H. Hadley, ed. Hybridization of crop plants. ASA and CSSA, Madison, WI.
94. Martin, T. J. 1990. Outcrossing in twelve hard red winter wheat cultivars. Crop Sci. 30: 59-62.
95. Marvier, M. and Van Acker, R. C. 2005. Can crop transgenes be kept on a leash? Front. Ecol. Environ. 3: 93-100.
96. Matus-Cádiz, M. A. and Hucl, P. 2003. Comparison of pretreatments for inducing germination in highly dormant wheat genotypes. Can. J. Plant Sci. 83: 729-735.
97. Matus-Cádiz, M. A., Hucl, P. and Dupuis, B. 2007. Pollenmediated gene flow in wheat at the commercial scale. Crop Sci. 47: 571-579.
98. Matus-Cádiz, M. A., Hucl, P., Horak, M. J. and Blomquist, L. K. 2004. Gene flow in wheat at the field scale. Crop Sci. 44: 718-727.
99. Mauro, I. J. and McLachlan, S. M. 2008. Farmer experiences and attitudes toward risks associated with genetically modified crops in Manitoba, Canada. Agric. Human Values (in Press).
100. McCaig, T. N. and DePauw, R. M. 1992. Breeding for preharvest sprouting tolerance in white-seeded-coat spring wheat. Crop Sci. 32: 19-23.
101. McCrate, A. J., Nielsen, M. T., Paulsen, G. M. and Heyne, E. G. 1982. Relationship between sprouting in wheat and embryo response to endogenous inhibition. Euphytica 31: 193-200.
102. Morris, C. F. and Paulsen, G. M. 1985. Preharvest sprouting of hard winter wheat as affected by nitrogen nutrition. Crop Sci. 25: 1028-1031.
103. Morrison, L. A., Cremieux, L. C. and Mallory-Smith, C. A. 2002. Infestations of jointed goatgrass and its hybrids with wheat in Oregon wheat fields. Weed Sci. 50: 737-747.
104. Nyachiro, J. M., Clarke, F. R., DePauw, R. M., Knox, R. E. and Armstrong, K. C. 2002. Temperature effects on seed germination and expression of seed dormancy in wheat. Euphytica 126: 123-127.
105. Ollerton, J. and Lack, A. 1998. Relationships between flowering phenology, plant size, and reproductive success in Lotus corniculatus (Fabaceae). Plant Ecol. 139: 35-47.
106. Özberk, I., Atli, A., Yücel, A., Özberk, F. and Coskun, Y. 2005. Wheat stem sawfly (Cephus pygmaeus L.) damage: impacts on grain yield, quality, and marketing prices in Anatolia. Crop Prot. 24: 1054-1060.
107. Pickett, A. A. 1993a. Cereals: seed shedding, dormancy, and longevity. Asp. Appl. Biol. 35: 17-28.
108. Pickett, A. A. 1993b. Hybrid wheat - Results and problems. J. Plant Breed. 15 (Adv. Plant Breed. Suppl.): 1-259.
109. Poehlman, J. M. and Sleper, D. A. 1995. Breeding field crops. Iowa State University Press, Ames, IA. 510 pp.
110. Prakash, S. and Singhal, N. C. 2003. Natural cross-pollination in bread wheat (Triticum aestivum). Seed Res. 31: 22-26.
111. Primack, R. B. 1980. Variation in the phenology of natural populations of montane shrubs in New Zealand. J. Ecol. 68: 849-862.
112. Rainboldt, C. R., Thill, D. C. and Young, F. L. 2004. Control of volunteer herbicide-resistant wheat and canola. Weed Technol. 18: 711-718.
113. Reddy, L. V., Metzger, R. J. and Ching, T. M. 1985. Effect of temperature on seed dormancy of wheat. Crop Sci. 25: 455-458.
114. Rieseberg, L. H. and Wendel, J. F. 1993. Introgression and its consequences in plants. Pages 70-109 in R. G. Harrison, ed. Hybrid zones and the evolutionary process. Oxford University Press, Oxford, UK.
115. Schoenenberger, N., Felber, F., Savova-Bianchi. D. and Guadagnuolo, R. 2005. Introgression of wheat DNA markers from A, B and D genomes in early generation progeny of Aegilops cylindrica Host x Triticum aestivum L. hybrids. Theor. Appl. Genet. 111: 1338-1346.
116. Seefeldt, S. S., Zemetra, R., Young, F. L. and Jones, S. S. 1998. Production of herbicide-resistant jointed goatgrass (Aegilops cylindrica) x wheat (Triticum aestivum) hybrids in the field by natural hybridization. Weed Sci. 46: 632-634.
117. Singh, K. P. 2001. Effect of water stress on seed germination and seedling growth of some wheat genotypes. Adv. Plant Sci. 14: 23-26.
118. Simard, M. J. and Légère, A. 2004. Synchrony of flowering between canola and wild radish (Raphanus raphanistrum). Weed Sci. 52: 905-912.
119. Smith, D. B. and Flavell, R. B. 1975. Characterization of the wheat genome by renaturation kinetics. Chromosoma 50: 223-242.
120. Snyder, J. R., Mallory-Smith, C. A, Balter, S., Hansen, J. L. and Zemetra, R. S. 2000. Seed production on Triticum aestivum by Aegilops cylindrica hybrids in the field. Weed Sci. 48: 588-593.
121. Statistics Canada. 2001. Wheat, by provinces (1981-2001 Census of Agriculture). [Online] Available: http://www.statcan.ca/english/freepub/ 95F0301XIE/tables/html/Table13Can.htm [2008 Jan. 25].
122. Statistics Canada. 2006. Canadian Statistics - field and specialty crops, by seeded area. [Online] Available: http://www40.statcan.ca/l01/cst01/ prim11a.htm [2008 Jan. 25].
123. Stone, A. E. and Peeper, T. F. 2004. Characterizing jointed goatgrass (Aegilops cylindrica) x winter wheat hybrids in Oklahoma. Weed Sci. 52: 742-745.
124. Stump, W. L. and Westra, P. 2000. The seed bank dynamics of feral rye (Secale cereale). Weed Technol. 14: 7-14.
125. Suneson, C. A. and Cox, E. L. 1964. Promiscuity in barley and wheat. Crop Sci. 4: 233-234.
126. Tanner, D. G. and Falk, D. E. 1981. The interaction of genetically controlled crossability in wheat and rye. Can. J. Genet. Cytol. 23: 27-32.
127. Thomas, A. G. and Leeson, J. Y. 1999. Persistence of volunteer wheat and canola using weed survey data. Page 88 in Expert Committee on Weeds Annual Meeting, Ottawa, ON.
128. Thompson, K., Ceriani, R. M., Bakker, J. P. and Bekker, R. M. 2003. Are seed dormancy and persistence in soil related? Seed Sci. Res. 13: 97-100.
129. Van Acker, R. C., Brûlé-Babel, A. L. and Friesen, L. F. 2003. An environmental risk assessment of Roundup Ready wheat: Risks for direct seeding systems in western Canada. Report prepared for the Canadian Wheat Board, Winnipeg, MB. 33 pp.
130. Van Acker, R. C., Brûlé-Babel, A. L. and Friesen, L. F. 2004. Intraspecific gene movement can create environmental risk: The example of Roundup Ready wheat in western Canada. Pages 37-47 in B. Breckling and R. Verhoeven, eds. Risk, hazard, damage - specification of criteria to assess environmental impact of genetically modified organisms. (Bundesamt fur Naturshutz) - Naturschutz and Biolische Viefalt, Boo, Germany.
131. Vavilov, N. I. 1951. The origin, variation, immunity, and breeding of cultivated plants. Chronica Bot. 13: 1-366.
132. Virmani, S. S. and Edwards, I. B. 1983. Current status and prospects for breeding hybrid rice and wheat. Adv. Agron. 36: 115-214.
133. Vogel, G. 2006. Tracing the Transatlantic spread of GM rice. Science 313: 1714.
134. Waines, J. G. and Hegde, S. G. 2003. Intraspecific gene flow in bread wheat as affected by reproductive biology and pollination ecology of wheat flowers. Crop Sci. 43: 451-463.
135. Wang, Z. N., Hang, A., Hansen, J., Burton, C., Mallory-Smith, C. A. and Zemetra, R. S. 2000. Visualization of A- and Bgenome chromosomes in wheat (Triticum aestivum L.) x jointed goatgrass (Aegilops cylindrica Host) backcross progenies. Genome 43: 1038-1044.
136. Wang, Z., Zemetra, R. S., Hansen, J. and Mallory-Smith, C. A. 2001. The fertility of wheat x jointed goatgrass hybrid and its backcross progenies. Weed Sci. 49: 340-345.
137. Wicks, G. A., Felton, W. L., Murison, R. D. and Martin, R. J. 2000. Changes in fallow weed species in continuous wheat in northern New South Wales, 1981-1990. Aust. J. Exp. Agric. 40: 831-842.
138. Willenborg, C. J. and Van Acker, R. C. 2006. Comments on "An empirical model for pollen-mediated gene flow in wheat" (Crop Sci. 45:1286-1294). Crop Sci. 46: 1018-1019.
139. Wilson, J. A. 1968. Problems in hybrid wheat breeding. Euphytica 17 (Suppl. 1): 13-33.
140. Wilson, H. K. and Hottes, C. F. 1927. Wheat germination studies with particular reference to temperature and moisture relationships. J. Am. Soc. Agron. 19: 181-190.
141. Wilson, W. W., Janzen, E. L. and Dahl., B. L 2003. Issues in development and adoption of genetically modified (transgenic) wheats. AgBioForum 6: 101-112.
142. Zemetra, R. S., Hansen, J. and Mallory-Smith, C. A. 1998. Potential for gene transfer between wheat (Triticum aestivum) and jointed goatgrass (Aegilops cylindrica). Weed Sci. 46: 313-317.