Yes, to a certain extent, you can keep back-up cultures of your plants.
many species, and selections within a species, will react differently to "in vitro" (meaning "in glass") culture techniques, but once figured out it can be a good way to propagate your plants if you have the know-how.
It is not too difficult to do, bbut it doesn't always make sense to do.
In my experience, mostly with non-succulent Euphobia spp. and papaya, you can leave a plant in a jar under light for weeks at a time, even months, with little problem. then when the plant starts to get too big or crowded, you open the jar, take out a couple shoot tips and put them in a new jar to start all over again.
Without liquid nitrogen, really long term storage where you dont have to interact with the plants would be difficult. even with liquid nitrogen, some plants might not like it. I have experimented with cultures under refrigeration a little, but it didnt work out very well. my plants looked pretty bad, and someone took the out and they died.
more later. I have to go. if anyone wants to discuss tissue culture further, should we start a thread? or does the op mind if we continue in this thread?
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