In silico identification and experimental validation of insertion-deletion polymorphisms in tomato genome

Comparative analysis of the genome sequences of Solanum lycopersicum variety Heinz 1706 and S. pimpinellifolium accession LA 1589 using MUGSY software identified 145 695 insertion-deletion (InDel) polymorphisms. A selected set of 3029 candidate InDels (≥2 bp) across the entire tomato genome were subjected to PCR validation, and 82.4% could be verified. Of 2272 polymorphic InDels between LA 1589 and Heinz 1706, 61.6, 45.2, and 31.6% were polymorphic in 8 accessions of S. pimpinellifolium, 4 accessions of S. lycopersicum var. cerasiforme, and 10 varieties of S. lycopersicum, respectively. Genetic distance was 0.216 in S. pimpinellifolium, 0.202 in S. lycopersicum var. cerasiforme, and 0.108 in S. lycopersicum. The data suggested a reduction of genetic variation from S. pimpinellifolium to S. lycopersicum var. cerasiforme and S. lycopersicum. Cluster analysis showed that the 8 accessions of S. pimpinellifolium were in one group, whereas 4 accessions of S. lycopersicum var. cerasiforme and 10 varieties of S. lycopersicum were in the same group.