Study of the progeny of two Brassicaceae weeds collected in proximity of oilseed rape.

CANTAMUTTO, M.,PANDOLFO, C. E., A., PRESOTTO, A., PAZ, N., SUARDIAZ, G., GIACHETTI, F., URETA, S., POVERENE, M.

Mar del Plata

Congreso; 2nd World Conference on Biological Invasions and Ecosystem Functioning; 2011

The potential hybridization between oilseed rape Brassica napus (BN) and invasive Brassicaceae species like Raphanus sativus (RS) and B. rapa (BR) could facilitate the evolution of new weed biotypes. We studied the second generation (G2) of two BR and two RS biotypes collected in overlapping flowering with BN (cv. Nexera 8450) at four sites of Buenos Aires province. This G2 was obtained under controlled conditions. Off-types plants (OT ¡Ý 2 atypical morphological traits) were detected by individual observation (n > 4400) in seed trays. A sample of OT individuals (n > 10) was grown and evaluated in pots in a complete random design, and typical plants as controls. Both RS biotypes showed phenotypic uniformity without intermediate traits or OT presence. The progeny of one BR biotype showed a minority group (> 3 ¡ë) of OT plants. The relative length of the siliqua beak of this group matched to the BR descriptors, while leaf color, stem-clasping, flower disposition and seed biomass corresponded to BN. In this group, abortion of reproductive branches and high mortality could indicate genomic imbalances. The second BR biotype showed a predominance of rapeseed traits, with a fraction (< 3 ¡ë) of OT plants showing BR leaf morphology, poor growth, low floral induction and abortion of reproductive branches. Intermediate traits and reproductive abnormalities observed in the second generation progeny after simultaneous flowering with oilseed rape of two BR populations do not rule out the existence of weed-crop hybridization processes.Brassica napus (BN) and invasive Brassicaceae species like Raphanus sativus (RS) and B. rapa (BR) could facilitate the evolution of new weed biotypes. We studied the second generation (G2) of two BR and two RS biotypes collected in overlapping flowering with BN (cv. Nexera 8450) at four sites of Buenos Aires province. This G2 was obtained under controlled conditions. Off-types plants (OT ¡Ý 2 atypical morphological traits) were detected by individual observation (n > 4400) in seed trays. A sample of OT individuals (n > 10) was grown and evaluated in pots in a complete random design, and typical plants as controls. Both RS biotypes showed phenotypic uniformity without intermediate traits or OT presence. The progeny of one BR biotype showed a minority group (> 3 ¡ë) of OT plants. The relative length of the siliqua beak of this group matched to the BR descriptors, while leaf color, stem-clasping, flower disposition and seed biomass corresponded to BN. In this group, abortion of reproductive branches and high mortality could indicate genomic imbalances. The second BR biotype showed a predominance of rapeseed traits, with a fraction (< 3 ¡ë) of OT plants showing BR leaf morphology, poor growth, low floral induction and abortion of reproductive branches. Intermediate traits and reproductive abnormalities observed in the second generation progeny after simultaneous flowering with oilseed rape of two BR populations do not rule out the existence of weed-crop hybridization processes.