Prospects for F1 hybrid production in ryegrass

Ryegrass is the primary pasture crop in New Zealand; however, despite this importance, gains in yield through conventional breeding have been marginal. Other significant crops, particularly maize and rice, have benefited from hybrid breeding programmes whereby heterosis has been exploited. Ryegrass presents many challenges to breeders wishing to produce F1 hybrid progeny on a large scale such as self-incompatibility, inbreeding depression, and a lack of genetic tools for creating and maintaining male-sterile lines for crossing. Many of these challenges have been overcome in other species, providing a basis for addressing them in ryegrass. With the advent of new technologies such as CRISPR gene editing and the genome sequence for ryegrass, F1 hybrid production is now possible on a large scale. Regulations in New Zealand surrounding new genetic tools are a hurdle which must be addressed to allow the agricultural industry in New Zealand to apply these advanced technologies.