Genome-wide association studies of Ca and Mn in the seeds of the common bean (Phaseolus vulgaris L.).

SNP markers linked to genes controlling Ca and Mn uptake were identified in the common bean seeds using DArT-based association mapping (AM). The Ca concentration in the seeds varied between 475 and 3,100 mg kg-1 with an average of 1,280.9 mg kg-1 and the Mn concentration ranged from 4.87 to 27.54 mg kg-1 with a mean of 11.76 mg kg-1. A total of 19,204 SNP markers were distributed across 11 chromosomes that correspond to the haploid genome number of the common bean. The highest value of ΔK was determined as K = 2, and 173 common bean genotypes were split into two main subclusters as POP1 (Mesoamerican) and POP2 (Andean). The results of the UPGMA dendrogram and PCA confirmed those of STRUCTURE analysis. MLM based on the Q + K model identified a large number of markers-trait associations. Of the 19,204 SNPs, five (on Pv2, 3, 8, 10 and 11) and four (on Pv2, 3, 8 and 11) SNPs were detected to be significantly related to the Ca content of the beans grown in Bornova and Menemen, respectively in 2015. In 2016, six SNPs (on Pv1-4, 8 and 10) were identified to be significantly associated with the Ca content of the seeds obtained from Bornova and six SNPs (on Pv1-4, 8 and 10) from Menemen. Eight (on Pv3, 5 and 11) and four (on Pv2, 5 and 11) SNPs had a significant association with Mn content in Bornova in 2015 and 2016, respectively. In Menemen, eight (on Pv3, 5, 8 and 11) and 11 (on Pv1, 2, 5, 10 and 11) SNPs had a significant correlation with Mn content in 2015 and 2016, respectively.

Association mapping for five agronomic traits in the common bean (Phaseolus vulgaris L.).

BACKGROUND: The common bean is the most important grain legume and a major source of protein in many developing countries. We analysed the following traits: pod fibre (PF), seeds per pod (SPP), plant type (PT), growth habit (GH), and days to flowering (DF) for a set of diverse common bean accessions and determined whether such traits were associated with amplified fragment length polymorphism (AFLP), simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers. RESULTS: In this study, 66 common bean genotypes were used and genotyped with 233 AFLP, 105 SNP and 80 SSR markers. The association analysis between markers and five traits was performed using a General Linear Model (GLM) in Trait Analysis by aSSociation, Evolution and Linkage (TASSEL). The population structure was determined using the STRUCTURE software, and seven groups (K = 7) were identified among genotypes. The associations for such traits were identified and quantified; 62 markers were associated with the five traits. CONCLUSION: This study demonstrated that association mapping using a reasonable number of markers, distributed across the genome and with the appropriate number of individuals harboured to detect DNA markers linked to the traits of PF, SPP, PT, GH and DF in common bean.