ROLE OF ENDOGENOUS HORMONES IN FRUIT DORMANCY AND GROWTH OF INDIAN GOOSEBERRY (EMBLICA OFFICINALIS GAERTN.)
Indian gooseberry (aonla) is evergreen in the tropics. It flowers in March-April on newly emerged determinate shoots in North India. Pollination and fertilization takes place within 72 hours of anthesis. Fertilized ovary of aonla, unlike those of other plants, remain dormant for 3.5 months and resume growth following division in endosperm and zygote nuclei in the last week of July and August. The fruits mature some time in November - December following double sigmoid growth pattern. Cytokinins (E1 -E6), gibberellins (X1 -X6) and inhibitors (R1 -R2) were present in low concentrations in dormant fruits and the dormancy was not due to deficiency of these hormones in the fruit. The factor playing a major role in the dormancy mechanism of fruit appear to be auxins (a1 -a5). Concentration of auxins increased in the fruit with the onset of dormancy and decreased to a low level prior to dormancy break. Shoots grew while fruits were dormant and dormancy break in fruits occurred after cessation of shoot growth. Since rise and fall in the rate of shoot growth correspond with the rise and fall in the auxin content of dormant fruits and shoot-tips and dormant fruits contained identical auxins, it is proposed that the auxins translocated from the shoot-tip to the fruit cause dormancy of fruits by a mechanism similar to that operative in apical dominance as also confirmed by the tracer technique of labelled IAA.
Ram, S. (1992). ROLE OF ENDOGENOUS HORMONES IN FRUIT DORMANCY AND GROWTH OF INDIAN GOOSEBERRY (EMBLICA OFFICINALIS GAERTN.). Acta Hortic. 321, 389-399