Molecular tagging of the Am gene from Lycopersicon hirsutum f. glabratum PI 134417 using AFLP markers

Recently important epidemics caused by Alfalfa Mosaic Virus (AMV) have been reported in field grown canning tomatoes in southern Italy. The Am resista nce gene identified in Lycopersicon hirsutum PI 134417 confers a complete r esistance to several isolates of AMV with different geographical and botani cal origins. In order to identify linked molecular markers, a segregant bac k-cross population of 120 individuals was obtained from the intraspecific c ross between the resistant L. hirsutum accession PI 134417 and the suscepti ble accession L. hirsutum PI 247087. Using bulked segregant analysis combin ed with AFLP technology, four AFLP markers were found to be linked to the A m resistance gene. This gene will be assigned to a tomato chromosome using L. pennellii introgression lines.