EFFECTS OF TREATMENT WITH GIBBERELLIC ACID ON GERMINATION OF PROTEA CYNAROIDES, P. EXIMIA, P. NERIIFOLIA AND P. REPENS (PROTEACEAE)

The seeds of South African Protea spp. (botanically achenes) show dormancy, which seems to be imposed by a low temperature requirement and by the action of the pericarp.

In order to study the effects of gibberellic acid (GA₃) on germination of Protea cynaroides, P. eximia, P. neriifolia and P. repens, seeds of those species were sown in a mixture of peat moss and lapilli (1:1 in volume), in plastic propagating trays which were placed in a well ventilated greenhouse.
Before sowing, seeds were imbibed for 24 h in either GA₃ (100 ppm) or distilled water (control). A randomized block design with two treatments and three replications was employed.
Fifty seeds per treatment were used.
The total number of seeds was three hundred for each species.
Germination was recorded weekly, for 21 weeks.
Percentages and rates of germination were calculated.

Imbibition by P. eximia and P. neriifolia seeds of a GA₃ solution (100 ppm) for 24 h, improved significantly its percentage and rate of germination.
Although GA₃ treatment improved percentage and rate of germination of P. cynaroides, this effect was not statistically significant. P. repens germination percentages were abnormally low and were not taken into account.

III International Protea Research Symposium

J.A. Rodríguez Pérez

https://doi.org/10.17660/ActaHortic.1995.387.9