Transgenic forage-type Italian ryegrass (
Lolium multiflorum Lam.) plants have been obtained by microprojectile bombardment of embryogenic suspension cells using a chimeric hygromycin phosphotransferase (
hph) gene construct driven by rice
Actl 5

regulatory sequences. Parameters for the bombardment of embryogenic suspension cultures with the particle inflow gun were partially optimized using transient expression assays of a chimeric

-glucuronidase (
gusA) gene driven by the maize
Ubi1 promoter. Stably transformed clones were recovered with a selection scheme using hygromycin in liquid medium followed by a plate selection. Plants were regenerated from 33% of the hygromycin-resistant calli. The transgenic nature of the regenerated plants was demonstrated by Southern hybridization analysis. Expression of the transgene in transformed adult Italian ryegrass plants was confirmed by northern analysis and a hygromycin phosphotransferase enzyme assay.
Key words Forage and turf grasses - Italian ryegrassLolium multiflorum
- Microprojectile bombardment - Transgenic plants
Communicated by N. Amrhein