Download Defining climate adaptive forage traits and genetic resources – Final Report on MPI Contract AGR30811

Responses to elevated CO2 were recorded for eight perennial ryegrass cultivars grown in the FACE site at Flock House. Genomic analyses were carried out on ryegrasses from the FACE treatment rings and the surrounding pasture. Growth of the ryegrasses was not changed under elevated CO2 but flowering dates were altered substantially. Early-flowering types flowered earlier than expected and later types were later than expected. Concentrations of the endophyte alkaloid epoxy-janthitrem were increased markedly with higher CO2. The potential risks to animal health imposed by elevated epoxy-janthitrem will need to be managed through plant breeding in future cultivars. None of the other endophyte alkaloids measured were changed by the CO2 treatment. The genomic analyses showed very little genetic variation in the old pasture ryegrass population at the FACE site after 17 year’s exposure to elevated CO2. This indicates that breeding for ryegrass performance in future CO2 conditions should initially be very widely based to optimise adaptation.