Naturally Occurring Cytokinins in Aonla (Emblica Officinalis Gaertn.) Fruit

SUMMARY The fruit of Emblica officinalis remains dormant for a period of 31/2 months after setting. Studies on endogenous cytokinin activity of the fruit including exogenous applications of cytokinin suggest that dormancy may not be due to cytokinin deficiency. Fruit making rapid growth following dormancy was found to contain six cytokinin‐like substances, active in the soybean cotyledon callus test. Three of these were tentatively identified as zeatin, zeatin riboside and zeatin nucleotide. The authors are grateful to Dr K. Koshimitzu, Kyoto University, Japan, for the gift of an authentic sample of dihydrozeatin and to the Council of Scientific and Industrial Research, New Delhi, for the award of Senior Research Fellowship to one of them (S.R.).