  Accessions are prospective sources of genetic variability, as well as
valuable genetic resources to deal with present and future crop breeding
difficulties. The assessment of population structure and genetic diversity of
tomatoes (Solanum lycopersicum L.) that have been distributed in Iraqi
Kurdistan region critical in breeding programs for the production of
high-yielding cultivars as well as widening the genetic base of tomato. Using
fruit quality indices and molecular markers, a panel of 64 tomato accessions
taken from six provinces of Iraqi Kurdistan Region, were analyzed for genetic
diversity and population structure. In the analysis of variance, the fruit
phenotypic data revealed a high level of significant variability among tomato
accessions. The most important characteristics for explaining fruit
morphological variability, according to principal component analysis (PCA),
were fruit weight, fruit size, fruit diameter, total soluble solids, and
moisture content. Seven clades with different fruit characteristics were
revealed in the cluster analysis. Genetic diversity and relationships among
accessions were analyzed using thirteen inter simple sequence repeat (ISSR),
twenty-six start codon-targeted (SCoT) polymorphisms, and fifteen conserved
DNA-derived polymorphisms (CDDP). The ISSR, SCoT, and CDDP markers generated
121, 294, and 170 polymorphic bands, respectively, showing a high prevalence of
polymorphism. The average polymorphism information content (PIC) values for
ISSR, SCoT, and CDDP were 0.81, 0.84, and 0.84, respectively. The accessions
were divided into two groups based on the cluster and STRUCTURE analysis
results. The Mantel test revealed that three sets of markers had positive and
significant relationships.
