Jesus I’m actually interested in this thread and had to skip to the end. The term that (AFAIK — I skipped a bunch) has not been posted here yet is senescence. My background is in growing mushrooms and this is a very real issue with mushroom isolates. Senescence is just the scientific term for age related decay. With mushroom cultures, they can be stored for a long time on slants, where the culture takes over the nutrient medium, stops growing, and is then refrigerated. Here’s a pic of my mushroom cultures on agar slants, many of them single strain isolates or clones of in vitro fruit bodies. As you can see from the label, these cultures are over 2 years old. If I were to pour a batch of plates and take some transfers, the plates would grow vigorously and I would then be able to rapidly and exponentially expand the culture on grain spawn. One of these slants could be grown into pounds of shrooms.
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So, with mushrooms, senescence is caused by too many cell divisions, which manifests in the culture’s failure to form mushrooms. A senescent mushroom culture will colonize a substrate but either not fruit at all or form fucked up, deformed mushrooms. This is what happens when you run a mushroom clone for too long, but I have no reason to believe this happens with cannabis because its biology is vastly different from mushrooms.
In my own limited cannabis experience, I’ve got one cut that I’ve done multiple generations of clones with, and after a year she hasn’t lost any vigor. I realize that this isn’t a sufficient amount of time to be able to tell. I’m only posting in here because I’ve heard and read conflicting accounts of the role senescence plays in cannabis, and I would like to know definitely how long you can keep a cut without noticeable vigor loss.
My questions all pertain to the age of the cut, and therefore the age of the original plant that was grown from seed, rather than anything to do with how many times removed a given cut is from the original plant.