SEED STRUCTURE AND GERMINATION OF CHERIMOYA (ANNONA CHERIMOLA MILL.)

S. De Smet, P. Van Damme, X. Scheldeman, J. Romero
Uneven and irregular germination of cherimoya (Annona cherimola Mill.) seeds results in difficulties in propagating this fruit tree. Prior to a germination test, structures of the ungerminated and germinating seed were studied and the different parts described. It was found that cherimoya embryo is small (3 – 4 mm) and located inside an impermeable testa, with the micropyle being the only entrance for water.

Different pre-applied treatments, soaking in different concentrations (ranging between extreme values of 500 – 10,000 ppm) of gibberellic acid (GA3), soaking for different periods (12 – 72 hours) in distilled water and chemical scarification with sulphuric acid were evaluated in germination percentage and germination rate. Gibberellic acid showed a clear positive effect on both germination percentage and rate, although no significant differences between different concentrations were noted. Soaking in distilled water for 48 – 72 hours or 12 hours in gradually cooling water (initial temperature 92 °C) also showed a significant effect although germination was much more spread over time and irregular, making it a cheaper though less effective alternative for phytohormone treatment. Significant differences between the control, and water and gibberellic acid pre-applications suggest the presence of dormancy in cherimoya seeds.

Germination was evaluated during a period of 900 days, at the end of which germination was still occurring although reduced to very low levels. Germination varied between 10 – 74.5% after 98 days and ranged 49.5 – 77% after 900 days over the different treatments. Uncontrolled temperature regime may probably account for similar peaks in the different germination curves.

De Smet, S., Van Damme, P., Scheldeman, X. and Romero, J. (1999). SEED STRUCTURE AND GERMINATION OF CHERIMOYA (ANNONA CHERIMOLA MILL.). Acta Hortic. 497, 269-288
DOI: 10.17660/ActaHortic.1999.497.14
https://doi.org/10.17660/ActaHortic.1999.497.14
dormancy, Andean fruits, gibberellic acid, pre-application treatment

Acta Horticulturae