The Effects of Seed Size on Hybrids Formed between Oilseed Rape (Brassica napus) and Wild Brown Mustard (B. juncea)

Background : Seed size has significant implications in ecology, because of its effects on plant fitness. The hybrid seeds that result from crosses between crops and their wild relatives are often small, and the consequences of this have been poorly investigated. Here we report on plant performance of hybrid and its parental transgenic oilseed rape (Brassica napus) and wild B. juncea, all grown from seeds sorted into three seed-size categories.[br/] Methodology/Principal Findings : Three seed-size categories were sorted by seed diameter for transgenic B. napus, wild B. juncea and their transgenic and non-transgenic hybrids. The seeds were sown in a field at various plant densities. Globally, small-seeded plants had delayed flowering, lower biomass, fewer flowers and seeds, and a lower thousand-seed weight. The seed-size effect varied among plant types but was not affected by plant density. There was no negative effect of seed size in hybrids, but it was correlated with reduced growth for both parents.[br/] Conclusions : Our results imply that the risk of further gene flow would probably not be mitigated by the small size of transgenic hybrid seeds. No fitness cost was detected to be associated with the Bt-transgene in this study

Conséquences des variétés génétiquement modifiées pour l'environnement, la biodiversité et les agrosystèmes

*INRA Dijon, Documentation, 17 rue Sully, BP 86510, 21065 Dijon cedex Diffusion du document : INRA Dijon, Documentation, 17 rue Sully, BP 86510, 21065 Dijon cedexNational audienc

Conséquences des variétés génétiquement modifiées pour l'environnement, la biodiversité et les agrosystèmes

*INRA Dijon, Documentation, 17 rue Sully, BP 86510, 21065 Dijon cedex Diffusion du document : INRA Dijon, Documentation, 17 rue Sully, BP 86510, 21065 Dijon cedexNational audienc

Polymorphisme et sélection pour la résistance aux herbicides chez les mauvaises herbes

196 ref. *INRA, Centre de Dijon (FRA) Diffusion du document : INRA, Centre de Dijon (FRA) Diplôme : Dr. d'Universit

Possibilités de croisements entre cultures transgéniques et plantes sauvages

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Questions à propos des variétés resistantes à des herbicides

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Selection pour la resistance aux herbicides

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Conséquences de l’utilisation des OGM sur l’usage des pesticides

Herbicide-resistant and insect-resistant GM crops have been grown in order to save pesticide uses. Although the first years in the USA showed some benefit, further observations could be interpreted as a slow down in pesticide reduction together with the appearance of threats to the sustainability of the GM technology. On the one hand, alternate techniques were improved so as to use less pesticide. On the other hand, the appearance of herbicide-resistant weeds lead to the come-back of heavy herbicide weed control programs. However, the reduction in insecticides was sustained thanks to the setting up of the refuge strategy. The USA experience must be taken into account to design and evaluate the impact of the GM crops on the “green” policies to reduce the amount of pesticides used in Agriculture

Some effects of herbicide-selection on Alopecurus myosuroides huds

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