FERTILE TRANSGENIC BARLEY OF DIFFERENT CULTIVARS OBTAINED BY ADJUSTMENT OF BOMBARDMENT CONDITIONS TO TISSUE-RESPONSE

Fertile transgenic barley (Hordeum vulgare L.) plants of five cultivar s were obtained by an improved transformation protocol using different particle delivery devices. Varieties of barley which are hardly amena ble for genetic transformation due to low tissue culture response were stably transformed by optimizing transformation parameters for each g enotype separately according to their tissue culture response. Scutell a of immature-zygotic embryos were transformed with the plasmid pAHC25 carrying the selectable marker gene bar and the reporter gene uidA. G ene delivery was optimized using the uidA-expression as transient mark er for the transformation efficiency and taking into account the maint enance of the regeneration capacity after the bombardment. After selec tion on media with bialaphos as selective agent, 40 independently tran sformed plants were regenerated and analyzed for functional expression of the bar and uidA gene. Molecular analysis by Southern hybridizatio n confirmed the integration of both genes into the nuclear genome of t he plants. Thirty-five T-0-plants of five barley cultivars reached mat urity so far. Analysis of the progeny confirmed the inheritance of the marker genes.