Starting Raspberries from Seed

Over the Winter, I had the opportunity to sprout wildcrafted black Raspberry seeds (Rubus occidentalis) that were collected in June of 2019. Before sprouting the seeds, I scraped the outer coating of the seeds with a medium sandpaper and soaked them in warm water for 24 hours. I then planted the seeds in a pot of seed starter and left the pot buried in the ground to stratify outdoors over Winter. I performed the same treatment on some wildcrafted blackberry seeds I had collected in 2018, but they did not sprout like the black raspberry seeds. I have posted a video documenting the results of the procedure on Bitchute:
https://www.bitchute.com/

Below are also some images of the blackberries I used for the procedure.

For some reason it amused me to think of how this process is mimicking the digestive tract of a bird. Curious, why did you choose to do go through this process with the seeds when these plants are perhaps easier to cultivate through other means?

Matt Todd wrote:For some reason it amused me to think of how this process is mimicking the digestive tract of a bird. Curious, why did you choose to do go through this process with the seeds when these plants are perhaps easier to cultivate through other means?

When raspberry seeds pass through the digestive tract of birds they are exposed to hydrochloric acid at pH levels of 2.0 or lower for several hours. The acid is so strong that it breaks down part of the outer layer of the raspberry seed. This makes the seeds more readily sprout after they are exposed to moisture and at least 30 consistent days of cold stratification.

Commercial plant breeders often use acid scarification for large quantities of seeds when breeding plants that have seeds that require scarification to sprout. I have even found a YouTube video demonstrating the use of sulfuric acid to break down the outer seed coat of Texas Mountain Laurel. Here is the relevant video:
https://m.youtube.com/watch?v=DUomnTjWB-c

Since I was working with a small quantity of seeds, I had no need for using hydrochloric acid to scarify large quantities of seeds since I could easily mimic the same process that occurs in the digestive tracts of birds by just rubbing the seeds with sandpaper.

For this germination procedure I chose to sprout black raspberry seedlings rather than dig up cains of the plant because I wanted to have a genetically unique plant without any potential diseases found in the parent plant. Black raspberry cains (Rubus occidentalis) are also not available at local nurseries in the Dayton Ohio area so propagation from fruit seed is currently the best option for me to propagate this plant.