Identification of Genetic Basis Associated With Agronomic Traits in a Global Safflower Panel Using Genome-Wide Association Study

Abstract

Safflower is an underutilized and minor oilseed crop that received less attention from the scientific community compared to other oilseed crops like soybean and sunflower. Exploring the genetic basis associated with agronomic traits is crucial for marker-assisted breeding of safflower. A genome-wide association study was conducted using a total of 12,232 DArTseq markers to identify the marker-trait association for important agronomic traits in an international safflower panel derived from 26 different geographical countries of the world. Statistically significant genotypic effects (p < 0.05) were observed across mean data of both locations (Pakistan and Turkey). Moderate to high heritability estimates were observed for the studied traits. Studied material showed higher performance for all traits except seeds per capitulum in Pakistan compared to Turkey. Phenotypic diversity for important agronomic traits, such as plant height (60.08 to 121.48 cm), capitula per plant (8.7 to 80.4), seeds per capitulum (15 to 42.05), and seed yield per plant (4.85 to 51.02 g), was illustrated. Seed yield per plant showed a highly significant and positive correlation with capitula per plant (0.4985***). Constellation plot analysis resulted in four groups, i.e. A, B, C, and D. Genotyping by sequencing resulted in 12,232 DArTseq markers being used for the investigation of marker-trait association through mixed linear model (Q + K) approach. DArT-38077549 showed significant association with capitula per plant, while two markers (DArT-22763576, DArT-22763253) were associated with plant height. A total of two markers (DArT-38079422, DArT-100043360) were associated with seeds per capitulum. A total of five DArTseq markers showed significant association with seed yield per plant and maximum variation was resulted by DArT-100004992. The results of this study provide a new insight to understand the genetic basis associated with agronomic traits in safflower. We envisage that significant markers identified through this investigation may be applicable in future safflower marker-assisted breeding programs.