An integrated high density RFLP-AFLP map of tomato based on two Lycopersicon esculentum x L-pennellii F-2 populations

Two independent F-2 populations of Lycopersicon esculentum x L. pennellii w hich have previously been investigated in RFLP mapping studies were used fo r construction of a highly saturated integrated AFLP map. This map spanned 1482 cM and contained 67 RFLP markers, 1078 AFLP markers obtained with 22 E coRI + MseI primer combinations and 97 AFLP markers obtained with five PstI + MseI primer combinations, 231 AFLP markers being common to both populati ons. The EcoRI + MseI AFLP markers were not evenly distributed over the chr omosomes. Around the centromeric region, 848 EcoRI + MseI AFLP markers were clustered and covered a genetic distance of 199 cM, corresponding to one E coRI + MseI AFLP marker per 0.23 cM; on the distal parts 1283 cM, were cove red by 230 EcoRI + MseI AFLP markers, corresponding to one marker per 5.6 c M. The PstI/MseI AFLP markers showed a more even distribution with 16 PstI/ MseI AFLP markers covering a genetic distance of 199 cM around the centrome ric regions and 81 PstI/MseI AFLP markers covering a genetic distance of 12 83 cM on the more distal parts, corresponding to one marker per 12 and 16 c M respectively. In both populations a large number of loci showed a signifi cant skewed segregation, but only chromosome 10 loci showed skewness that w as similar for both populations. This ultra-dense molecular-marker map prov ides good perspectives for genetic and breeding purposes and map-based clon ing.