Effect of drying seeds

drying does not appear to have a detrimental effect on the viability of rose seeds that are germinated using embryo culture<<<<<<

I agree with this, Don. I also find that dry achene is easier to grab onto with less slippage, which is helpful to the seed extraction step. Also some of the dried achenes have very dried seed which has shrunk back, and there is an air gap between seed and achene wall, which makes it less likely to injure the seed during the seed extraction step of embryo culture (at least in my case using the knife).

If I were to choose fresh seed to dry seed to work with in embryo culture, I would choose dry seed any day for these reasons (as long as it is not dried to the point of brittleness/near death).

In my experience, dry/viable embryos literally explode with activity as soon as they hit water. Dry/but near dead (or dry/dead) embryos can look undamaged but remain pallid and dull, and are ovbviously non(or minimally)-responsive to water challenge in the first few hours post extraction, and ultimately wither away sometimes showing obvious mold attack.

Just my observations.

In October last year, I posted these comments on this thread:

I have planted seed extracted with the box cutter and with no cutting of their seed coat, (as well also planted bare embryo) in seed-raising mix, with all the nasty bugs it contains… and germinations occured. Usually the germinations take 10-14 days, sometimes it takes a little longer. Certainly by 4 weeks no more germinations can be expected<<<<<<<<<

Now I was not getting consistently good % germinations by doing this at that time, and I surmised that maybe the embryos NEEDED a period of jar culture to enhance their germinability. I am not so sure any more…

You know, since then a lot has happened. I recently planted about 30 embryos as bare embryos (pre-soaked for about 12-24 hours in water), and I deliberately skipped the jar culture altogether.

I nearly got 100% germination! I kind of ignored this at the time, as I percieved there was some “safety factor” in the jar culture step.

I am NOW thinking that the reason in the early days I was NOT getting this sort of success with skipping the jar culture altogether (in just burying bare embryos without culturing them) was that I was planting them too deeply and/or was watering them too frequently and forcefully, causing them to sink too deep and/or to rot. Maybe all I need to do is to tweek the planting and watering of the embryos in the first critical days before their germination.

Today, I have nine embryos I extracted from a single hip, and they were about to get jar cultured…

However, I am going to plant them in pre-soaked seed raising mix and roll them into a small hole in the wetted mix, then lightly cover them with a few millimetres of wetted mix, using droplets/light watering, making sure the embryos do not dive deeply into the mix. This mix holds water very well, so I will not water them thereafter (I will however mist the surface of the mix once every few days if it starts to dry out). I will keep them in shade, out of the rain and elements until germination.

This is exactly what I did with the 30 embryos a few weeks back, and got nearly all of them germinating.

Quiet honestly, if this does work again for me with good the % germiantion I noted recently, I will abandon my jar culture step altogether…lol

Will post results soon.

Here they are at the moment.

They have just finished a 12 hour water soaking.

Now gonna plant 'em!