Regeneration and sanitation by stigma/style somatic embryogenesis ofCitrus genotypes in Algeria: preliminary results

Abstract: Stigma/style somatic embryogenesis is one of the efficient methods in plantregeneration of most Citrus spp. with the exception of Clementines, without inducingsomaclonal variations in regenerants. Furthermore, somatic embryogenesis from style andstigma culture proved to be effective in the elimination of the main citrus virus and virus-likediseases. This technique was applied on Algerian citrus collection. The main citrus local andinternational varieties of different citrus species (Citrus sinensis, C. limon, C. reticulata, C.maxima and C. paradisi) were chosen and tested for the presence of the main virus andvirus-like agents. Most of the genotypes showed to be infected by one or more infectiousagents, primarily viroids. Closed flowers were collected from these genotypes duringblossoming and, after sterilization, cultured on a MS medium supplemented with mg/l BAP(6-benzylaminopurine). All explants produced callus at the cut end of the styles, about 4-9days after culture initiation, whereas embryogenesis occurred later (after 38-150 days) inmost of the cultured genotypes. Formed embryos were cultured in a single tube before invivo acclimatization, which was performed by grafting onto in vivo seedlings. After sanitaryassays, plants regenerated from stigma/style culture showed to be free from the agents anddiseases detected in the mother trees.