Hormonal control of fruit growth and fruit drop in mango cv. Dashehari.
Ram S.
Author Affiliation: G.B. Pant University of Agriculture and Technology, Pantnagar 263 145, India.
Acta Horticulturae : 169-178
Abstract : The pattern of fruit growth was sigmoid and auxin levels increased and decreased with the rate of fruit growth. GA content in the seed increased rapidly during early seed growth and declined as growth decreased. The seed was the major source of gibberellin in the fruit with the pericarp containing only traces. Cytokinins were present both in the pericarp and seed. During a single period of rapid fruit and seed growth, cytokinin concentrations increased rapidly at 2 stages. The first (rapid increase) preceded the period of rapid cell division and cell enlargement and the second coincided with the period of rapid cell enlargement only. The level of ABA-like inhibitor was high in the first 21 days preceding pollination, which corresponded with the period of slow fruit growth and heavy fruit drop. During the period of rapid fruit growth, the level of inhibitors decreased and that of promoters increased. However, during the period of maturation and slow fruit growth, the levels of growth promoters and inhibitors were low. Deficiency of auxins, gibberellins and cytokinins coupled with a high level of inhibitors caused fruit drop.