Re-orientation and integration of the classical and interspecific linkage maps of the long arm of tomato chromosome 7

To obtain reliable classical and integrated interspecies maps of the long a rm of chromosome 7 of tomato, detailed mapping work was undertaken and seve ral phenotypic and molecular markers were assigned loci on both maps to pro vide reliable cross-reference points. To maximise the value of the new maps , pair-wise segregation data for classical genetic markers from the literat ure were included, based on large segregating populations with readily scor able phenotypes. In addition, to increase confidence in these maps, introgr ession lines were used to confirm important map locations. The revised clas sical map is based on two- and three-point test-cross data from a number of F-2 and BC1 mapping populations. The integrated interspecies map is based on F-2 mapping populations derived from crosses of Lycopersicon esculentum with Lycopersicon pennellii (LA716). The genetic analyses for both maps wer e performed using the computer package JoinMap. The revised composite class ical map indicates that some of the map positions reported in the literatur e are incorrect. The linear order of the classical markers common to both t he revised classical and integrated interspecies maps are in complete agree ment. Production of the integrated interspecies map resulted in re-orientat ion of the existing molecular map.