Association mapping for grain diameter and weight in lentil using SSR markers

The grain diameter and weight are important traits in lentil influencing grain yield, cooking time and consumer preference. In this study association mapping panel of ninety-six diverse genotypes representing genotypes from India and Mediterranean region was assessed at three locations in India (Delhi, Indore, and Dharwad representing different cultivation zones) for grain size and weight. Hundred grain weight ranged from 1.24 to 5.8 g across the locations and grain diameter from 1.91 mm to 5.98 mm. Marker-trait associations (MTAs) were analysed with 425 markers (365 EST-SSRs and 60 genomic markers) using mixed linear model (MLM). The characterization of genetic variation using STRUCTURE analysis revealed the presence of six sub-populations. Neighbor-Joining method of clustering also confirmed six clusters. The MLM approach identified association of PBALC 224 (R2 value 7%) with grain diameter and GLLC 614 (R2 value of 13%) and PBALC 29 (R2 value of 15%) with grain weight. The reported SSRs exhibited the marker-trait association across the all studied environments. The identified SSRs exhibited consistent performance across three locations. This study can help in breeding new lines with enhanced grain diameter and weight using marker-assisted selection (MAS) in lentil.