Abstract

The source-sink relationship between leaves and fruits during the flowers and young fruits abscission of Mangifera indica L. cv. Cat Hoa Loc was investigated. A lot of changes occurred in the source leaves, including a decrease in starch concentration and an increase in respiratory rate at periods 2 and 3 (periods of flower growth). Chlorophyll a and b content and photosynthetic rate underwent very little at the periods 1-4 (period 1: period of flower initiation). The amounts of the plant hormones: auxins, gibberellins, cytokinins and abscisic acid were measured in the leaves. The most important changes in these substances were a auxin decrease and an abscisic acid increase, during the periods of easy abscission (periods 3 and 4).