REGENERATION OF TRANSGENIC PLANTS FROM WALNUT SOMATIC EMBRYOS MEDIATED WITH AGROBACTERIUM TUMEFACIENS

An Agrobacterium-mediated transfer system that targets somatic embryos has been successfully exploited for regenerating transgenic plants of walnut. Several somatic embryo lines from ovules, cotyledons and embryonic axes of immature fruit of English walnut (Juglans regia L.) were infected with a hypervirulent Agrobacterium tumefaciens strain C58C1 ATHV RifR containing the helper plasmid pEHA101 and a binary vector p35-gus-int. Putative transformed somatic embryos were selected for continued proliferation on a DW (1/2 DKW + 1/2 WPM) medium containing 100 mg l-1 kanamycin. The histochemical assessment showed fully expression of the b-glucuronidase (gus) gene in the 3rd and later generations of the inoculated somatic embryos. No significant differences in transfer rates were observed among the somatic embryo lines derived from different explant sources. Polymerase chain reaction (PCR) assays confirmed the presence of the neomycin phosphotransferase II (nptII) gene in all gus positive embryos tested. Several somatic embryos from different transformed lines were germinated and converted into plantlets. The expression of the gus gene and the nptII gene was observed in the regenerated plantlets.

IV International Walnut Symposium

H. Tang, Z. Ren, M. Wallbraun, G. Reustle, G. Krczal

genetic manipulation, Juglans, polymerase chain reaction (PCR),

https://doi.org/10.17660/ActaHortic.2001.544.27