Lutein content in petals and leaves of marigold and analysis of lutein synthesis gene expression

Lutein is a bioactive natural carotenoid that is a member of the oxygen-containing carotenoids, and marigolds are the main raw material for the extraction of lutein. The lutein content in the leaves and petals of eight varieties of marigold including two inbred lines and six nuclear male sterile AB lines was measured using high-performance liquid chromatography (HPLC). The results showed that lutein was mainly stored in the petals of marigold, which had a lutein content 20 times higher than that in the leaves. Additionally, the lutein content in male parent 3 was the highest among the eight varieties of marigold in both petals and leaves. Correlation analysis showed that the expression level of the LCYE gene in the petals was positively correlated with the lutein content, with a correlation coefficient of 0.82, and the expression level of the LCYB gene in the leaves was positively correlated with the lutein content, with correlation a coefficient of 0.77. This study laid the foundation for the evaluation of parental resources and quality breeding of pigment marigold.