Unlocking the genomic regions associated with seed protein contents in Turkish common bean germplasm through genome-wide association study

Human body needs sufficient quantity of protein on daily basis for the normal functioning. Dietary protein in sufficient quantity is becoming a key issue for huge population of the world particularly in developing countries. Present investigation aimed to explore the phenotypic variation and to investigate the genomic regions associated with seed protein contents in Turkish common bean germplasm collected from 19 provinces. Field experiments were conducted according to augmented block design at two locations (Bolu and Sivas) for two consecutive years (2017 and 2018). Analysis of variance revealed highly significant environmental effects (p < 0.05) on seed protein contents within environments, while genotype by environment interaction revealed nonsignificant effects. Overall mean protein contents were 36.36%, while Balikesir-3 and Hakkari-38 yielded minimum (31.64%) and maximum (40.70%) protein contents. Among 19 provinces, accessions from Hakkari and Erzincan provinces disclosed maximum and minimum mean protein contents respectively. Scatter plot between seed protein contents and plant height divided the accessions according to their protein contents and plant height. A total of eight stable accessions were selected and can be recommended for future breeding activities. The implemented constellation plot separated the studied germplasm into two populations on the basis of their protein contents. Genotyping by sequencing resulted 7900 DArTseq markers was used for marker-trait association and a total of 11 markers showed significant association for protein contents. During this study, DArT-3365703 marker was identified in both locations (Sivas and Bolu) during 2017 and might be used for future common bean breeding. Physical map revealed the presence narrow regions between identified markers on Pv02 and Pv05. Therefore, these regions should be considered for future breeding activities. We are confident that results of present study will be helpful for marker-assisted breeding of common bean.