Carotenoid Extraction and Quantification from Flowering Petals

Carotenoid were extracted from fresh petals at the flowering stage and detected following the methods of Cao et al.^{51 (link)}. Carotenoid analysis was performed using LC-2010AHT HPLC (Shimadzu, Kyoto, Japan) with C30 column (YMC, Kyoto, Japan). Carotenoids were identified by the typical retention time of the standard compounds, including violaxanthin (Sigma-Aldrich, Saint Louis, America), lutein (Solarbio, Beijing, China), α-carotene and β-carotene (Wako, Osaka, Japan). The identification of prolycopene was performed based on reported the typical retention time and relative order of carotenoid compound peaks^{22 (link),43 (link),51 (link)}. Carotenoid content was quantified according to Morris’ method^{52 (link)}. The total carotenoid content was the sum of all the detected carotenoid compound contents. Three biological replicates were used for all analyses and the calculation of means and standard deviations were conducted. The significant difference between 92S105 and 15S1040 was analyzed by t-test.