Agrobacterium tumefaciens‐mediated transformation of forage‐type perennial ryegrass (Lolium perenne L.)

Abstract

Perennial ryegrass (Lolium perenne L.) is one of the most important grass species in the world’s temperate zones. It is used as high-quality forage in pastures and for recreational use as turf in golf courses, lawns and parks. However, genetic improvement of perennial ryegrass is difficult due to its self-incompatibility. Consequently, progress by conventional breeding can be slow. Genetic transformation is an alternative that permits direct introduction of useful genes into a plant’s genome and is becoming a powerful tool to complement conventional breeding. Transgenic perennial ryegrass has been obtained by direct transformation using microprojectile bombardment (Spangenberg et al. 1995; Dalton et al. 1999; Altpeter et al. 2000) or silicon carbide fiber (Dalton et al. 1998) for both forageand turf-type cultivars. Transgenic turf-type plants have been successfully generated using Agrobacterium tumefaciensmediated transformation (Wu et al. 2005). In this study, we generated a transgenic forage-type perennial ryegrass plant by infecting calli induced from the shoot tips of perennial ryegrass with A. tumefaciens, using the βglucuronidase (gus) and hygromycin phosphotransferase (hpt) genes as the selective markers.