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What the hell is an f2?


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Yeah, pretty dumb question, as when I see people talking about these things they always seem to know what they're on about ... everyone seems to know what these are except me.


All I know is that it has something to do with genetics and possibly breeding lines, and that an f1 seed justifies a much greater sell price than an f2 seed e.g Serious Seeds vs Nirvana Seeds...


Are f1's really better than f2's...? Like are they more pure or something? Hrmmm.


Thanks :D

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The tag F1 refers to the first generation of the result of crossing two distinct strains of plants. The parents are called the P1 generation. And F2 means the result of crossing two F1's together.


Just quickly, genetic traits are coded by alleles, which are held in pairs on the chromosome. These pairs split during reproduction to create gametes, (ova and pollen) which will have half of the genetic information of the plant. Each plant contributes half of the genetics for any particular trait.


When you cross 2 plants of different strains, which have different traits, let's take short and tall plants for instance, (It's a little more complex, but you'll get my drift.) you'll get progeny from that cross called the F1 generation. This F1 generation will have characteristics somewhere inbetween those of the parent plants. So in this case, almost all of the plants will be of a height between the two, let's call it standard. Now, these plants will have what is called "hybrid vigor". These tend to grow vigourously, and have strong, diversified genes, which makes for a healthier plant.

Now, when you take two plants from the F1 generation, and cross these two together, what do you get? The F2 generation! This generation will throw up much different plants from the F1's. You'll get about 1/2 of the plants staying standard height, 1/4 short and 1/4 tall. Within the tall and short plants you will also end up with some which are significantly taller and shorter than any others. This is because you've inbred the line. Some of the plants are coming out with both genes for shortness, some get both genes for tallness, and some get one of each. Those with one of each allele for a trait are the heterozygous plants, and those with both genes for one trait are homozygous plants. In that trait anyway. In other words, you know that the plants which are tall in the F2 generation will have both genes for tallness, which makes for a purebreeding tall plant. When you start breeding the F2 generation with each other, you can really start to create individuals of exceptional traits, (not necessarily good ones, just purely expressed) because if you were to cross two of the short plants together from the F2, then you'll know that all the progeny will be small too, because there are two genes for shortness in both plants....

So in short, if you want strong plants, which are able to survive and thrive in much wider environmental ranges, then go for an F1. If you are after a particular trait though, like a plant that will love growing under lights, or extremely short, then go for an F2 cross, as these are stabilised for their traits.

I hope this has made sense, and I certainly hope I got it right. whitecluster is another one who knows about this stuff, maybe he'll correct my errors..... :D

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what errors?? I cant see none really. an F3 isn't stabilised for any traits, it might be on the way depending on male selection, which will involve keeping clones of all fathers and testing his children to see which male possessed the trait you desired. but its not true breeding for that trait. That will take a few seasons of inbreeding. The trait you chose tall/short is one of the few traits that can be shown in males.


Basically if you wanna buy good strains to grow and keep as mothers, buy F1's

If you want plants to make seeds from, buy a true breeding inbred line, a plant past its 4th backcross, or a pure landrace.

Avoid F2's and F1's of 2 different F1's.


In the old days I'm sure a plant that would keep its good traits year after year would have been one of the most important traits. But these days with all the indoor growing and mother keeping, F1's are the best because of the vigour. But some F1's will never compare with the parents, just because of shitty parent selection from low plant numbers.


Just my observations, no kind of fact.


Anyway, everytime I see that GWS family tree I always wonder about it. What we're the traits the 2 different lines we're chosen for?? and surely they used alot more breeding plants than that. Great White Shark is a bit of a favourite of mine and my 1st AAA grade strain I bought. I'd love to know where the fuck that picture originates from.

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Awsome that explains it all. I think f1 seeds will suit my purpose as I want to find a mother plant (or 5) that are as consistent as possible.


Thanks for the help guys lol

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Why so many mothers? Wouldn't one or at most two do the job? Unless you plan on growing out several different strains that is, but then you would end up with some problems if they were all growing in the same room. Two strains at once under one light is managable, but I don't know about 5, unless you were willing to put in the extra work. If they were all from the same cross tho, you should do okay with one or two mothers, see what I mean?
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