See abstract below:
When I worked at the Forest Service I initiated and regenerated somatic embryos of Spruce. It’s amazing to see the clusters of callus with beautiful embryos. When I would try to take embryos directly and try to germinate them on fresh callus they would not develop normally (they became hyperhydridic-took on excess water). Only after a period of drying down the embryos with things with high osmostic potential-Polyethylene glycol, sugars, and or lowered humidity… did they germinate normally.
Drying down to some degree appears to be a critical step in seed development and maturation for many species. Even though we don’t necessarily “dry” our rose seeds, there seems to be somewhat of a drying process even as the maturing embryo is on the plant. The drying process helps to change abscissic acid slightly and make it soluble so it can be leached out once the seed is imbibed.
I try not to let my rose seeds dry out after extraction from the hips, but I know many who do. I wonder if one would let them dry for a short time and imbibe them in water before stratification if one can leach out more ABA and improve germination??? I know some friends who store their rose seeds dry for years even until they are ready to grow them and often they have good germination. I got some dried R. multiflora seed from a friend (stored in the fridge) that was over a year old. I imbibed them and in a month at room temp there was a high rate of germination.
What has been others experience with dried rose seed?
I was given some R. eglanteria seed that hed been stored under less than ideal conditions ( ie dried out, in paper bag )for aprox 2 years.
I was concerned they would not germinate, but have germinated so well that I have more than I can realistically handle, that is unless I can master budding onto small seedlings.