Though I never came across this issue generally people also try Gibberellin
treatment to induce germination. But I would first try to germinate them
normally (stratify them at 4C for at least three days). If not then try GA
treatment as follows.
1. GA: 16.5 mg/ml in EtOH (GA 4+7 Duchefa Biochemicals). Dilute to 1:20
2. Add 8 ul of 1:20 dilution of GA and 2 ml of 0.1% agar in a 15 ml tube
with your seeds.
3. Vortex carefully and incubate overnight at 4C.
4. Add 8 ml water and mix.
5. Plant in the soil and stratify at 4C for 3 days.
Shajahan Anver, PhD
Department of Plant Microbe Interactions
Max Planck Institute for Plant Breeding Research
Carl-von-Linné Weg 10