From a single spore print, many strains can be isolated. For this experiment, the fastest and most rhizomorphic strain was colonized out, along with the slowest and most cottony strain. All the mushrooms below, came from the same spore print, at the same time. A single zigzagging swipe on agar from an innoculation loop. This should show you how much variation is possible when just using multispore innoculation.
One half of the pie plate was filled with one strain, and the other half filled with the other. This is the best way to test your strains and see very clearly which is most favorable on a genetic level. The next step in the process would be to then clone the largest, fastest fruitbody on the "good" side of the pie plate, and you then have your super strain of Cubensis or whatever species you are working with.
These happen to be Treasure Coast.
Quote:As you can see...the half that's on the right in the pictures is obviously superior to the half on the left of the pie plate. That is the side that the cultivator should clone and use for subsequent large trays
Faster, more vigarous strains do grow out and overtake more of the substrate than slower, more cottony mycelium. All I have done is taken the bad and the good mycelium, separated it, and put the bad on the left, and the good on the right.
So...lets say you get a jar and inject it with multispore innoculation. All of the germination sites start growing outward. How many germination sites are rhizomorphic and how many are cottony is gonna just be luck of the draw (hence the biggest problem with multispore innoculation), but lets say that for this example, you get 50% of good and 50% of bad genetic material. And for this example, we will totally ignore the unsuccessful couplings that result in monokaryotic mycelium that just eats substrate nutrition and doesn't ever fruit.
The faster, stronger, rhizomorphic mycelium will grow faster, and overtake 75% of the jar, while the slow crappy stuff only manages to get 25% of the jar.
You then dump this into a tray, and 75% of the tray fruits strongly, and one quarter of the tray fruits like total garbage, but this is disguised by the fact that its all mixed together, and not neatly separated like in my pictures above. Is it worth it to you to get 100% of the tray to fruit well? To get all those little empty spots between the musrooms to fill up with mushrooms? To some, its not worth the extra work.
The real point of strain isolation is this: If you were serious about it and not just trying to make a pretty picture for demonstration purposes like I've done above, you would isolate 10 different rhizomorphic sectors and ignore all cottony garbage. You would then do pie plates of all 10 of them, and then pick the very best genetic base of those to take to large trays. You would pick the one with the largest fruits, the fastest growth, and the most abundant pinset. Then, those trays not only are 100% great fruiting mycelium, without the little gaps of 25% crappy stuff in between all the fruit, but are also what would equate to the best parts OF THE BEST JAR OUT OF 10 JARS that you would get if multispore innoculated!!
That means, if you were to use multispore innoculation on 10 jars, only 7.5% of your jars would be of the very best fruiting genotype. One jar would have mostly (75%) great fruiting genes and only a little bit (25%) of garbage sprinkled around it. All the rest of your jars, would have 75% that wasn't quite as good, and 25% that weren't good at ALL.
With strain isolation, you can take that 7.5% that is ultimate, and make it 100% of your crop. All 10 jars, would be 100% full of that very best 7.5% of your genetic pool. HOLY COW! And that's how the big boys do it.
Well, unfortunately, there is only so much that genetics can do for a given mushroom. For example...in humans, when a mother and father mix a batch of sperm and an egg, there are many given traits in genetic material there, as potential. Keeping this in simple terms, the father is going to bring lots of "half-traits" and the mother is going to bring lots of "half-traits". If the one sperm that makes it to the egg first has a half-trait for color blindness, and the egg also has this half-trait...the child will be color-blind. (Since it is a sex linked trait, it will also likely be male.) If just the sperm or just the egg have this half trait, but the other doesn't...the child wont have color blindness, but will still have the half-trait floating around in its DNA for when it mates later in life. This is the reason that such a taboo formed around brothers and sisters having sex. If you have a baby with your brother/sister, you and your sibling have all the same "half-traits", and the baby will end up having any bad genes you carry around as a family. It is not uncommon for babies born out of brother/sister copulation to have color blindness, baldness, hemophelia, crooked teeth, mental retardation, etc, etc, etc...all because you are mating with someone with all the same negative half-traits.
A sporeprint is the same. It has a family tree, and a lineage. There are a given number of positive traits, and a given number of negative traits in all the DNA of a given spore print. After several iterations of cloning and printing and cloning and printing, the best you can hope for is a strain where every bad trait has been eliminated, and all the good traits are present.
You will never improve a given mushroom beyond this point without the help of evolution. Mushrooms WILL evolve to better utilize the home cultivation environment that you are growing it in, after many generations. This may appear to the grower as though he is improving the genetics, by continued cloning and printing...but the mushrooms are actually just doing more with the DNA they have to work with, through the miracle of evolution.
But you can keep a mushroom strain very strong, healthy and free of negative genetic traits with this method.
The reports you hear of continued cloning resulting in mutation are reports from commercial growers. The range of mutation and strain degradation is around 1000 generations before you start seeing it. Think about how long a home cultivator would take to run out 1000 generations. You are not likely to have a problem with strain degradation in your lifetime. Commercial growers run trays in a constant cycle 24-7, year round, for 5 generations in their families. Yea, "the strain that someones great grandfather started back in 1934 is starting to degrade and now we have to go back to sporeprint, etc..." is the sort of reports you may get about strain degradation, but its not as serious or common of a problem as you might think. I doubt we could find a single individual on the OMC, besides possibly Paul Stamets, who has witnessed first hand, strain degradation from consecutive cloning.