'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 INTROGRESSION MAPPING TO ISOLATE THE ‘STAY-GREEN’ GENE B.J. MOORE, T.H. JONES, H. THOMAS, R.N. JONES, W.G. MORGAN, J. KING, I.P. KING, J.A. HARPER, T. FENTEM, H.M. THOMAS Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, SY23 3EB, Wales

A mutant plant of meadow fescue (Festuca pratensis) has provided the ideal germplasm source for producing ‘stay-green’ varieties in which the genetic process leading to chlorophyll breakdown has been disrupted. By studying and manipulating this colour-influencing trait, we can introduce it into a ryegrass (Lolium) background where the small segment introgressed from the donor fescue parent contains a single ‘stay-green’ gene. Placing of this major gene, and a number of linked molecular markers, on the Lolium/Festuca genetic map will enable the selection of tightly linked markers and their presentation as part of a “Breeder’s Toolkit”. The development of this ‘molecular screening package’ will allow marker assisted selection of this desirable trait and will support the trialling, validation and marketing of novel grass varieties within the UK and worldwide.