Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/1998
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Molecular breeding of barley for complementation of the enzyme spectrum with thermotolerant endo-beta-glucanase aims at improved processing quality. The gene coding for a fungal thermotolerant beta-glucanase was introduced to Finnish malting barley variety Kymppi under the regulation of the barley alpha-amylase promoter. Thus the gene was expressed only during ggermination. The genetically modified barley line expressed the foreign gene correctly and the enzyme synthesized was active even at elevated temperatures. The proliferation of plants homozygous with respect to the transgene by anther culture resulted in sterile plants. This problem did not occur in our earlier studies using a neomycin phosphotransferase marker. It is still an open question whether the gene itself, the regulation or the integration locus harmed the normal development of the transgenic line. Our results indicate very strongly that barley transformation is variety dependent. With the variety Kymppi the bombardment of 13,000 embryos resulted in only one transgenic line, whereas the bombardment of 250 Golden Promise embryos has already yielded 20 transgenic plants and the regeneration is still in progress. Possibly the difference is due to high nuclease activities. The heat stability of the beta-glucanase enzyme produced by these new transgenic Golden Promise lines is under investigation. Our strategy for the future is to cross the transgenic Golden Promise lines with Finnish malting varieties. By backcrossing assisted with genetic markers the unwanted genome will be bred out. Using genetic marker-assisted backcrossing the selected progeny will have more than 99% of the genome of the recurrent parent after only two crosses.