ASSESSMENT OF THE GENETIC STRUCTURE AND SALT TOLERANCE OF Phaseolus vulgaris L. LANDRACES

The common bean (Phaseolus vulgaris L.) is one of the most important crops in the world. Landraces represent great importance as a gene resource for developing varieties. For this reason, revealing their genetic structure and introducing them into breeding programs are necessary. In this study, the genetic structure and salt stress tolerance levels of common bean landrace genotypes were investigated. This work aimed to contribute to breeding studies by revealing the relationship between genetic structure and tolerance to salt stress. For this purpose, the population structure of 124 common bean landrace genotypes was revealed by using 30 simple sequence repeat markers. Furthermore, the salt tolerance levels of these genotypes were determined in accordance with their vegetative development under control and salt stress conditions. For this purpose, the salt stress index was used. As a result, the genotypes were clustered into six populations. The growth habits of genotypes were the determining factor in clustering. STRUCTURE analysis supported this result, and allele sharing between genotypes with different growth habits was found to be limited. Only one genotype was identified as tolerant. However, 10 genotypes were classified as moderately tolerant. All of the tolerant and moderately tolerant plants were climber genotypes. The limited allele sharing detected between the bush and climber genotypes suggested that alleles related to salt tolerance accumulated in climber genotypes. These results showed that hybridization between bush and climber genotypes should be conducted to not only create variation for breeding but also to contribute to salt stress tolerance and to increase stress-related allele sharing.