On a color change from yellow to red in the floral tissues of a dyer's saffron cultivar

Abstract

Summary By using a spot scanning technique, the color change from yellow to red manifested in the floral tissues of Mogami-Benibana, a cultivar of dyer's saffron ( Carthamus tinctorius L.), was investigated. Stamens and pistils were separated from fresh florets of the herbaceous flowering plant for microscopic observation of the zones of red color development. In pistils, color change is localized in the stigma and the peripheral region of the stylar canal. Observations of the fibrovascular bundle are especially indicative that the pollination process coincides with induction of the red shift. GA 3 was found to be a stimulator of tissue reddening, while IAA showed no effect. All red products isolated from the test samples were identical with authentic carthamine.