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or t he popul ation of wild r adish (Guéritaine and D armency 2001; G uéritaine e t a l. 2003;
Ammitzboll a nd Jorgensen 2006) . A dvanced ba ckcross ge nerations ( BC6) r esemble c losely
typical wild radish (Guéritaine et al. 2002) and the resilience of a transgene encoding for a
herbicide-resistance was shown to be stable over eleven generations under selection pressure,
although not i ntrogressed ( i.e. l ocated on a s upernumerary chromosome, A l M ouemar a nd
Darmency, 2006) . F or t hese pur poses, w ild r adish popul ations w ere c ollected f rom t he
Normandy r egion ( France) where o ilseed r ape w as cultivated f or m ore t han 2 00 years.
Introgression, if any, is likely to occur in locations where co-occurrence of the two species
spanned for the longer time. The putative introgressed populations (Normandy), populations
from a n a djacent r egion ( Brittany) and ot hers f rom t wo di stant r egions ( Burgundy and
Denmark) w here o ilseed r ape c ultivation is r ecent w ere cultivated to gether to s tudy th e
morphological, growth and reproductive differences among them. The objective was to detect
the r oles of i ntrogression oppor tunities a nd ge ographic di stance i n t he di vergence of
morphologic t raits, a nd w hether t he put ative i ntrogressed popul ations ha ve a p articular
behavior in the field.
Materials and methods
Plant material
Wild r adish popul ations w ere s ampled i n f ields in t hree r egions i n F rance, t wo i n B rittany
(near Rennes: BT), two in Burgundy (near Dijon: BG1 and BG2), three in Normandy (near
Caen: NM1, NM2, NM3), and one in Denmark (DM, provided by RB Jorgensen) (Fig.4.1).
The c ultivation of oi lseed r ape n ear C aen, i n N ormandy, i s e stablished b y r ecords on
Communal Archives since 1802, a nd then it has been continuously grown in the region (D.
Poulain, unpublished data), while oilseed rape is a recent crop in the other regions, at best for
40 y ears (X. P inochet, unpublished C ETIOM d ata). Thirty pl ants of e ach popul ation w ere
grown in Dijon in 2008 i n separated insect-proof cages (3m length× 3m width× 2m height)
continuously pr ovided with hous eflies, Musca d omestica, i n or der t o f acilitate r andom
pollination. The seeds harvested in each cage were used for the following experiments.
Silique and flower morphology
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