EFFECTS OF COLD STRATIFICATION AND GA3 ON GERMINATION OF ARBUTUS UNEDO SEEDS OF THREE PROVENANCES
Pipinis, Elias; Stampoulidis, Athanasios; Milios, Elias; Kitikidou, Kyriaki & Radoglou, Kalliopi
Background: Arbutus unedo is a valuable Mediterranean shrub as an ornamental plant as well as fruit tree. Fresh fruits of A.
unedo are a good source of antioxidants, of vitamins C, E and carotenoids and also are characterized by the high content of
Materials and Methods: The effects of gibberellic acid (GA3) and cold stratification (CS) on seed germination performance were
investigated in A.
unedo seeds collected from three provenances in the Northern part of Greece. Seeds of each provenance were
soaked in solutions of GA3 (500, 1000 or 2000 ppm) for 24 h and subsequently were subjected to CS at 3 – 5ºC for 0, 1, 2, and 3
Results: Non-stratified seeds of the three A.
unedo provenances which were not treated with GA3 solutions exhibited very low
germination. However, seed germination was significantly improved after a one-month period of CS. Similarly, the non-stratified
seeds of all three provenances became non-dormant after the treatment with 2000 ppm GA3 and they germinated at high
percentages. However, in untreated seeds with GA3, after a one-month CS period the seeds of the Pieria provenance exhibited
higher germination percentage than that of Rodopi provenance seeds. Furthermore, in non-stratified seeds, the Pieria provenance
seeds treated with GA3 germinated at higher percentages and more rapidly than those of the other two provenances.
Conclusion: The results indicated that untreated seeds exhibited very low germination at 20/25ºC. However, in all three
provenances seed germinability was significantly improved by a one-month period of CS or treatment of seeds with 2000 ppm
GA3. Furthermore, there was a considerable variability among seed provenances in response to the treatments which were applied.
pre-germination treatment; seed dormancy; strawberry tree; Mediterranean species