The Aquifoliaceae comprise more than 300 species of trees and shrubs within three genera. The fruits are drupes and contain several bony seeds or nutlets. The seeds show orthodox storage behaviour.
SEED DORMANCY AND GERMINATION
Dormancy can be a major problem: successful dormancy-breaking treatments are available but can require substantial treatment periods. Effective dormancy-breaking treatments consist of alternating between warm stratification and pre-chill treatment regimes. Detailed information on seed germination and dormancy-breaking treatments is limited (Table 23.1), but the algorithm below may be helpful in developing suitable germination test procedures.
RBG Kew Wakehurst Place algorithm
The first step in the algorithm is to imbibe two samples of seeds at 26°C for 4w (i.e. a warm stratification treatment) with light applied for 12h/d. One sample is then moved to a constant temperature regime of 2°C and the other sample moved to a constant temperature regime of 6°C. In both cases light is applied for 12h/d.
If these treatments are not successful in promoting full germination then the second step of this algorithm is to alter these regimes slightly. For example, increase or reduce the period of warm stratification. Also test further seed samples in alternating temperature regimes of 23°/9°C (12h/12h) and 33°/19°C (12h/12h) with light applied for 12h/d during the period spent at the upper temperature after the initial warm stratification (26°C)/pre-chill (2°-6°C) treatment.
TABLE 23.1 Summary of germination test recommendations for species within the Aquifoliaceae
|
Species and Authority |
Substrate |
Temperature |
Duration |
Additional directions |
Source |
|
Ilex aquifolium L. |
|
|
|
warm stratification, 25°C, 40w, then pre-chill,
1°-5°C, 24w |
G&R |
