Variability in lutein and zeaxanthin content, fatty acid and phytosterols profiles, and genetic parameters of some Tagetes spp. cultivars

Lutein and zeaxanthin are oxygenated carotenoids with strong antioxidant and photoprotective properties, widely used in pharmaceuticals, cosmetics, and food. To identify Tagetes cultivars with higher pigment content, ten cultivars from T. erecta and T. patula were cultivated using a randomized complete block design with five replications. Agronomic and phytochemical traits, including carotenoids, lutein, zeaxanthin, fatty acids, and phytosterols, were evaluated. Significant variability was observed, particularly for flower diameter, total carotenoids, lutein, fresh flower weight (FFW), and antioxidant activity. FFW ranged from 10.28 to 23.28 g per plant, and dry flower weight from 2.70 to 5.67 g. Carotenoids, lutein, and zeaxanthin contents varied from 6.20 to 15.92, 2.44–6.42, and 1.05–2.48 mg/g DW, with cultivar TP5 showing the highest levels. Palmitic acid (34.12–49.15%) and linoleic acid (18.4–29.12%) were the dominant fatty acids, while TE2 had the highest β-sitosterol (207.34 µg/g FW). Genetic analysis indicated high heritability and genetic advance for carotenoids, lutein, zeaxanthin, antioxidant activity, and flower diameter, suggesting additive gene effects. This study provides the integrated morphological, phytochemical, and genetic assessment across diverse Tagetes cultivars, identifying promising candidates for breeding programs and industrial exploitation.