I found this on another forums and I thought I would post it here,
all credit goes to workman
Workman's Psilocybe Cubensis Breeding Method
By multiple requests, the hybrization method. This is the highly simplified version with as few technical terms as I can muster. It still requires some agar work and only works within a single species. In this example we are crossing strains of Psilocybe cubensis
Classic mushroom breeding requires the isolation and germination of single spores of both parents and then letting the mycelium from both parents cross in a petri dish. This is a precise and controlled breeding method but it is tedious and time consuming. It requires the isolation of many single spores and many petri dishes in the hopes of a few viable crosses.
This simplified method still requires the isolation of at least one monokaryotic mycelium from a single spore. To get the single spore mycelium I just streak an agar petri dish with a small amount of spores (serial dilution as described in The Mushroom Cultivator (Stamets) also works). At the end of the streak there are usually just a few spores on the agar. As soon as the tiniest bit of germination is noticed, transfer the smallest bit of mycelium to a fresh plate. Select single isolated germination points far from any clusters. The mycelium from a single spore grows slow, isn't rhizomorphic and can't fruit. You can confirm that the mycelium is monokaryotic by looking at a bit of the mycelium under the microscope (monokaryotic mycelium lacks clamp connections), but its usually pretty obvious by the way the mycelium grows. If you don't have a microscope you can skip the confirmation step.
Now that you have your petri dish of monokaryotic mycelium, the hard part is over. The next step is to innoculate some spawn with this mycelium and let it grow to near completion. Once the spawn is fully run with mycelium but not completely white you can proceed to the next step. Don't expect the jar to colonize as fast as multispore or fruiting clones.
Once your monokaryotic jar is ready you can add parent #2 in the cross. The nearly colonized jar should be fairly contaminate resistant at this stage so you don't have to be exceptionally careful now. Open the spawn jar lid and scrape in some spores of parent #2 or make a fresh syringe and inject some spores. The syringe should be freshly made as spontaneous germination can deflower the spores within. Shake the jar and let incubate for at least a week or two.
What is Happening?
What we started with was a jar of monokaryotic mycelium but when we added the parent #2 spores, some of them germinated and fused with the monokaryotic mycelium which becomes a dikaryotic mycelium by nuclear migration. Essentially the entire monokaryotic culture becomes dikaryotic by replicating and moving nuclei in a sort of a chain reaction through the already existing mycelial network. Since there isn't any available uncolonized substrate left in the spawn, any spores of parent #2 that fuse with each other won't have enough resources to produce any mushrooms.
Fruit the spawn directly (don't add to bulk substrate) and all the mushrooms produced should be varietal hybrids. The beauty of this method is you (or a friend) only have to produce a single petri dish of monokaryotic mycelium to make as many crosses as you like. You will want to start with your best performer for parent #1 and then you can easily make crosses with any prints you have around for parent #2. Maintain the parent monokaryotic mycelium with periodic transfers to new plates. Its also a good idea to use a very distinct strain for parent #1 since many cubensis look similar and it may not be visually obvious if the cross worked. In my example I used the distinct Falbino strain as the monokaryotic parent #1. Its pretty obvious when the jar produces pigmented mushrooms that the cross was successful.
It is important to realize that the F1 mushrooms are 50% of each parent at this stage but the spores they produce are genetically recombined. This means the prints are not going to breed true and any prints you distribute at this stage won't often produce mushrooms that look like the F1 generation. Only clones of the F1 mushrooms will be the same. To stabilize a new strain you need to grow out the F1 prints to produce F2 prints with selection of the mushrooms that have the traits you want. You need to do this for 5 or 6 sequential generations with selection before the strain can be considered stable.
Edited by Sidestreet, 04 September 2016 - 02:20 PM.