TRANSGENIC BARLEY BY PARTICLE BOMBARDMENT - INHERITANCE OF THE TRANSFERRED GENE AND CHARACTERISTICS OF TRANSGENIC BARLEY PLANTS

Transgenic barley plants (Hordeum vulgare L. cv. Kymppi) were obtained by particle bombardment of various tissues. Immature embryos and micr ospore-derived cultures were bombarded with gold particles coated with plasmid DNA carrying the gene coding for neomycin phosphotransferase II (NPTII), together with plasmid DNA containing the gene for beta-glu curonidase (GUS). Bombarded immature embryos were grown to plants with out selection and NPTII activity was screened in small plantlets. One plant proved to be transgenic (T-0). This chimeric plant passed the tr ansferred nptII gene to its T-1 progeny. The presence of the nptII gen e was demonstrated by the PCR technique and enzyme activity was analyz ed by an NPTII gel. assay. Four T-0 spikes and 15 T-1 offspring were t ransgenic. The integration and inheritance was confirmed by Southern b lot hybridization. Transgenic T-2 and Tg plants were produced by isola ting embryos from green grains of transgenic T-1 and T-2 plants, respe ctively and growing them to plants. After selfing, the ratio of transg enic to non-transgenic T-2 offspring was shown to follow the rule of M endelian inheritance. The general performance of transgenic plants was normal and no reduction in fertility was observed. Microspore-derived cultures were bombarded one and four weeks after microspore isolation . After bombardment, cultures were grown either with or without antibi otic selection (geneticin(R) or kanamycin). When cultures were grown w ithout selection and regenerated plants were transferred to kanamycin selection in rooting phase, one out of a total of about 1500 plants su rvived. This plant both carried and expressed the transferred nptII ge ne. The integration was confirmed by Southern blot hybridization. This plant was not fertile.