The tomato Introgression lines (ILs) are a set of nearly isogenic lines (NILs) developed by Dani Zamir through a succession of backcrosses, where each line carries a single genetically defined chromosome segment from a divergent genome. The ILs, representing whole-genome coverage of S. pennellii in overlapping segments in the genetic background of S. lycopersicum cv. M82, were first phenotyped in 1993, and presently this library consists of 76 genotypes. The IL lines on this map have been characterized based on the markers on the 1992 tomato map. ILs have also been mapped
with the ExPEN2000 map as a reference.