Rapid production of transgenic turfgrass (Festuca rubra L.) plants

Red or golf course fescue is a major turfgrass in the temperate regions. Regenerable mature embryo-derived callus cultures could be initiated from six out of seven European turf-type red fescue cultivars with significant genotypic differences in the callus induction- and -regeneration frequency and the number of regenerated plantlets per explant. The highly responsive cultivar Borfesta was chosen to develop a rapid transformation system. Biolistic gene transfer of a constitutive nptII expression cassette in freshly established callus was followed by paromomycin selection during callus subculture and regeneration. Transgenic plants were transferred to soil less than 5 months from the excision of explants. Between 3 and 5% of the bombarded calli produced independent transgenic plants, which converts into 1 to 1.7 independent transgenic plants per bombardment. Transgene integration was confirmed by Southern blot analysis. No nontransgenic plants that escaped the selection process were regenerated, indicating a tight selection scheme. Transgene copy number and transgene expression were variable from line to line, as indicated by Southern- and Western blot analysis respectively. A transgenic plant with a high transgene copy number showed the highest transgene expression level. This is the first report on transgenic turf-type red fescue plants.