The Changes of Endogenous Cytokinins During Fruit Development in Litchi(Litchi chinensis)
JIZuoliang and Wang Gangtao(Department of Horticulture,South China Agricultural University,Guangzhou,510642)
Three cytokinins:zeatin ,dihydro-zeatin and dihydro- zeatin- riboside were found in Litchi fruit extract byHPLC. Concentration of cytokinins in the fruit was highest during the first two weeks after anthesis and thendecreased and leveled off. Application of BA(6- benzyl-aminopurine)on the fruits reduced fruit drop effec-tively only when treated sixth day after anthesis. The concentration of cytokinins remained low during thefruit storage. Postharvest treatment of the fruits with BA retarded senescence and preserve quality of thefruits. It reduced the losses of sugar and organic acid of the fruits.