Variation of chlorophyll and carotenoids in different varieties and organs of Chinese kale

The concentrations of chlorophyll and carotenoids were analyzed in two organs (leaves and bolting stems) of 19 varieties of Chinese kale (including four maturity periods and two flower colors). Two chlorophylls and four carotenoids were identified in Chinese kale. The concentrations of chlorophyll and carotenoids varied widely in different organs and varieties. JL-03 was a good candidate for the future breeding programs, since it contained the highest concentrations of chlorophyll and carotenoids (except violaxanthin) in leaves. Lutein was the main component of carotenoids and accounted for approximately 50% of total carotenoids. The concentrations of chlorophyll and carotenoids in leaves significantly exceeded those in bolting stems. Principal component analysis showed that organ was the main source of differences of chlorophyll and carotenoid concentrations in different varieties of Chinese kale, while the maturity and flower color have little effect. Correlation analysis identified a significantly positive correlation between chlorophyll and carotenoids in Chinese kale. These results provided evidence for improving human dietary nutrition and breeding of Chinese kale.