[1] So Illinois Univ, Dept Plant Biol, Carbondale, IL 62901 USA
[2] Univ Angers, INRA, GenHort UMR1259, AGROCAMPUS OUEST Ctr Angers,Inst Natl Hort & Pays, F-49045 Angers, France
[3] Univ Nacl Comahue, CONICET, Lab Ecotono, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina
[4] Utah State Univ, Dept Biol, Logan, UT 84322 USA