Assessment of possible hybridization between Bt cotton (Gossypium hirsutum L.) and other Malvaceae species (Abelmoschus spp. and Hibiscus spp.) cultivated in Burkina Faso

Abstract

The cultivation of transgenic cotton in Burkina Faso should consider the possible hybridizations with cultivated cotton relatives like okra (Abelmoschus spp.) and roselle (Hibiscus spp.), when these crops are often sympatric and co-flowering. The possibility for Bt cotton and these crops to outcross was investigated in Farako-Bâ research centre, in the south sudanian zone. The study was carried out in 2007 using both open-pollinated and artificial pollination experimental designs. Results show that the studied species are effectively reproductively isolated because of low overlapping of their optimum flowering periods. In the case of the artificial crossings (direct and reciprocal) between the studied species and the Bt cotton, the results show that fruits were produced at different rates depending on the species being crossed and the crossing direction. Immunological tests done on progeny seeds resulting from the crosses with transgenic cotton as the male parent confirmed that there was a transfer of transgenes from Bt cotton to the conventional cotton (99.2%). The absence of the transgenes in the seeds of okra and roselle means that these seeds are not the result of intergeneric hybridization but could be attributed to self-pollination or parthenogenetic development of un-fertilized ovules. Key words: Transgenic cotton, relatives’ species, intergenera hybridizations, immunological test, Burkina Faso.