Evaluation of some Tomato (Solanum Lycopersicum L.) Genotypes for Blossom-End Rot Incidences through Physiological Measurements and ISSR-Markers

Background: Irregular traditional watering practices paired with moisture stress and calcium deficiency cause Blossom-end rot (BER) in tomatoes. As with other abiotic stresses and physiological disorders, BER affects the growth of tomato plants phenotypically and physiologically. In this study, we measured some physiological parameters as a response to BER in nine tomato genotypes, indicating the health and strength of plants and fruit yield. Results: Genotypes varied in the studied traits; Severyanka genotype recorded the highest results in maturity and fruit taste, while Dubok was the lowest in these two traits. While the 023-F1 as a locally grown genotype recorded good Chl/Car ratio results. Also, we used ISSR PCR technique to detect molecular markers for tomato genotypes that give 76.07% polymorphism, 0.363 PIC (Polymorphic Information Content), 0.479 of estimated He (Expected Heterozygosity) and 4.72 for EMR (Effective Multiplex Ratio). Based on the ISSRs data analysis with the UPGMA method, the nine-tomato genotypes were divided into two main groups according to their similarities. Six positive ISSR markers were found related to the Chl/Car ratio for the locally grown 0.23-F1 genotype, and by drawing the kinship tree, we found that it belongs to the group of some genetically superior genotypes, such as Severyanka and Majnat. Conclusion: The locally grown 023-F1 genotype was very similar in the studied traits to western genotypes and can be introduced into breeding programs to improve its traits for BER resistance further.