State of the art in old seed germination (embryo rescue, etc.)

[OldCoolSativa]

Greetings all. I think most of us who've been growing for a while have old seeds they'd love to revisit but can't germinate. Can you imagine the treasures from the past that we could unlock if we could resuscitate 50-year-old seeds?

I've read everything on ICMag I can find about germinating old seeds, and have tried a variety of techniques, although I have yet to build a flow hood and try my hand at sterilization procedures. About five years ago I was gifted my hippie sister-in-law's seed collection. She saved seeds from the best pot she ran across from the late 1960s until seedless weed became the norm in the 1980s. I can guarantee you there are some pure sativa landrace gems in this collection: Colombian gold, Panama red, Mexican, and RKS.

I've run through about a fifth of these seeds to date with no success at germinating. The closest I've gotten was when I manually cracked a seed that threw a root then died off.

I've decided to keep the rest of these seeds safe in the freezer until embryo rescue technology improves, or until some other method of germinating really old seeds becomes viable. I suspect many others are doing the same thing.

So I'd like to understand and stay updated on the very latest tech in rescuing old seeds. There's an IG user in Rhode Island who has a lot of good tech on tissue culturing, but his focus seems to be on propagation, not germination.

So, what's the latest hotness on embryo rescue and such?

 

[OldCoolSativa]

Following up on this, one of the things that I plan to do is design and build a very small jig to mechanically grasp and hold a seed. I've found that there's active germplasm in the old seeds I've tried to pop but it can't get out of the old, stiff, woody seed husk. I've manually scarified old seeds with my fingers and 600-grit sandpaper; this allows moisture to enter the seed more easily and can make it easier for the hust to split. But what's really needed is a means to carefully hold the seed and mill or abrade the perimeter along the split line. This would make it much easier for the embryo to crack the seed along the thinned/weakened seam. So maybe that along with a truly sterile environment could get some of these really old seeds too pop.

 

[Dj_Greenhouse]

You could consider using phytohormones such as gibberellins (GA) or indol acetic acid (IAA) . There are reports that they increase germination rates even under stress conditions, but I havent found any paper where they try this with old seeds.