'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 MOLECULAR MAPPING OF STAY GREEN ABILITY OF THE FLAG LEAF IN WHEAT V. VERMA, P.D.S CALIGARI, J. FOULKES, J.W. SNAPE, A.J. WORLAND John Innes Centre, Norwich, NR4 7UH and University of Reading, Reading, RG6 6AS, UK

Molecular markers now allow the possibility of simplifying the genetic analysis of complex agronomic traits, and effects can be mapped effectively as quantitative trait loci (QTL) using double haploid (DH) mapping populations.  To map genes for stay green ability of the flag leaf, and other characters in wheat, a DH population was developed from the cross between two European winter wheat varieties, Beaver x Soissons differing in this trait.  A molecular marker genetic map was developed on the population using simple sequence repeat (SSR) and Amplified Fragment Length Polymorphism (AFLP) markers, and stay green ability of the flag leaf was measured on individual plants of each DH recombinant line growth in a randomised and replicated field trial.  As a first step to detecting new loci, one-way analyses of variance were used to detect the associations between individual markers and the quantitative data for phenotypic traits.  Molecular markers explaining variation for percentage green flag leaf area was detected on chromosomes 5B and 7B.  Further genetic analysis of this population is ongoing using more sophisticated QTL analysis methods, and will hopefully, provide breeders with diagnostic markers for the selection of this trait in wheat.