Longevity of Rubus Seeds after Long-term Cold Storage

Seeds of 25 blackberry (Rubus spp.), five red raspberry (R. idaeus L.), and two black raspberry (R. occidentalis L.) populations that had been stored for 22 to 26 years were planted in the greenhouse to evaluate their germination. Germination ranged from 0% to 84% among all populations. Thorny and thorny × thornless blackberry populations had the highest average germination; most populations had >40% germination. Thornless blackberry populations ranged from 1% to 16% germination. The seeds of two of the five red raspberry populations did not germinate and none of the black raspberry seeds germinated.