Naturally Occurring Cytokinins in Mango ( Mangifera indica L.) Fruit

The fruit of mango (Mangifera indica L.) contained cytokinins in both pericarp and seed. During the single period of rapid growth in fruit and seed (7-42 days after pollination), cytokinin concentration increased rapidly at two times. The first preceded the period of rapid cell division and cell enlargement and the second coincided with the period of rapid cell enlargement only. Deficiency of cytokinin in the fruit appears to favour fruit drop and cessation of fruit growth. Eleven cytokinin fractions were isolated by ion-exchange column and paper chromatography from immature mango fruits. These fractions were termed Mf1 to Mf11, on the basis of their RF values and spectral properties. Two of these, Mf9 and Mf10, could be tentatively identified as zeatin riboside and zeatin, respectively.