Comparative analysis of polymorphism and chromosomal location of tomato microsatellite markers isolated from different sources.
Previously isolated tomato ( Lycopersicon esculentum) microsatellite markers were mainly clustered in the centromeric heterochromatin and not located in euchromatic regions. To achieve a more-uniform distribution of microsatellite markers for genome mapping purposes, a set of tomato microsatellite markers containing dinucleotide simple sequence repeats were developed by screening genomic libraries enriched for single-copy sequences, and screening the tomato EST database. The tomato microsatellites isolated in these ways were characterized by combinations of different types of repeated motifs and they were polymorphic in a set of L. esculentum varieties detecting up to four alleles. A total of 20 markers were placed on the genetic map of tomato. Interestingly, all markers isolated from genomic libraries enriched for single-copy sequences by PstI-pre-digestion mapped into the centromeric regions. The majority of markers derived from EST sequences contained predominantly AT microsatellites and were located in euchromatic regions.
Areshchenkova
T.
T
Institute for Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany. ganal@ipk-gatersleben.de
Ganal
M. W.
MW