1. M. Lefort-Buson, B. Guillot-Lemoine, and I. Bartkowiak-Broda , 1987 : A Brassica study of rapeseed (Brassica napus) F1hybrids from lines of same and different geographic origins. Proc. 7th Intern. Rapeseed Congress 11-14 , May1987 , Poznan, Poland. Vol. 1 , 630 -68 .