Biochemical Changes in Abscised and Non-abscised Aonla (Emblica officinalis Gaertn.) During Fruit Development

The present study was carried out in aonla cv. 'Balwant' to investigate the biochemical changes occurring in the abscised and non-abscised fruits at three stages of fruit development at monthly intervals, viz. pinhead stage, one month before harvest and at harvest. The fruit weight, dry matter content and antioxidant activity were significantly higher in retained fruits compared to the abscised ones during the different stages of fruit development. In the non-abscised fruits, the pectins, 1-diphenyl-2-picrylhydrazyl (DPPH) activity, total soluble sugars and proteins were higher, providing mechanical strength and assimilates for strengthening the fruits preventing their abscission. The activity of hydrolytic enzymes polygalacturonase and cellulase were statistically higher in abscised fruits compared to the non-abscised ones. The findings depict the important role of polygalacturonase and cellulase in the phenomenon of abscission. The auxins generally reduce the abscission by reducing the sensitivity of cells of the abscission zone to ethylene. Hence, further studies on understanding the mechanism of abscission through molecular approaches could help to elucidate molecular markers for the management of fruit drop by regulating expression of cell wall degrading enzymes and the use of auxins.