To understand the genetic relationship of almost all cultivars and the potential reason how these phenotypic difference formed, we re-sequenced over 1000 cultivars which are from different countries and regions in the world. LettuceGDB contains DNA polymorphs across over 1,048 strains from re-sequencing datasets, including 70,792,508 SNPs, 3,019,784 insertions and 2,849,453 deletions, which located in over 35,142 gene loci.
Based on the SNPs (single nucleotide polymorphism) of all samples, we re-constructed the relationship between different main cultivars as the following figure (Figure 1).
Figure 1. Phylogenetic relationship of main cultivars based on SNPs.