[1] Univ Saskatchewan, Ctr Crop Dev, Saskatoon, SK S7N 5A8, Canada
[2] Univ Saskatchewan, Dept Plant Sci, Saskatoon, SK S7N 5A8, Canada
[3] Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2E9, Canada
[4] Natl Res Council Canada, Inst Plant Biotechnol, Saskatoon, SK S7N 0W9, Canada