Exploring natural variation in seed oil traits across the global germplasm of the oilseed crop, Carthamus tinctorius L. (Safflower) using near-infrared reflectance spectroscopy and gas chromatography

Safflower is a drought-resilient crop with seed-oil rich in unsaturated linoleic and oleic acids . However, the low oil content has deterred its adoption as a major oilseed . We profiled a global collection of 1497 safflower accessions from twelve regional gene pools for their seed-oil content and fatty-acid composition. Oil content was estimated using the non-destructive Near-Infrared Reflectance Spectroscopy method based on a newly calibrated equation. Our findings highlight significant variability in the global reference collection for oil content, which ranged from 11.24 % to 59.16 %. The robustness of our calibrated equation was demonstrated by the strong correlation between datasets from two years (0.68 %). Furthermore, germplasm evaluation for fatty acid composition using gas chromatography revealed substantial diversity in linoleic (8.22–87.27 %) and oleic acid (6.98–85.84 %) content of safflower seeds . Collectively, accessions from USA and Indian subcontinent gene pools exhibited greatest variability in seed oil traits. In total, we identified eight accessions with very high oil content (>50 %), four accessions with high oil content (>40 %) coupled with desirable oleic acid (>75 %). The present work will aid safflower breeding programs. • Development and validation of robust NIRS calibration equation for oil in safflower. • Identification of a wide range of oil content (20 %-59 %) in safflower global germplasm. • Analysis of global germplasm to identify high-oil accessions with desirable composition. • This study has potential applications in crop improvement breeding programs.