The Institute of Cell Biophysics in Russia raised plants of Silene stenophylla (Campion Family) from fruit stored in Siberian permafrost by squirrels over 30,000 years ago. Currently, that permafrost is 20-40 meters below ground level.
They could not germinate the mature SEEDS they found, but were able to get plants from "placental tissue" in the fruit itself. The plants they grew were subtly differtent from contemporary plants of the same species: evolution in action.
The previous germination/propagation age record was a 2,000 year old date palm from Masada.
So maybe our LONG-term storage plans shouldn't be freezing seeds, but whole fruit?
30,000 year old fruits sprout
You are faster than I am. I came over to post this story.
Now this IS a Heirloom.
For more goggle 30,000 year old seed