Okay...first of all, I want to explain in a bit more detail here what some have already stated.
The F1 is the initial cross. (a x b) In this generation, you find fairly homogeneous, plants that express a fairly even balance of both parents. Some traits from A and some traits for B. These plants also show more vigor and usually express higher yields. When you move forward and take (a x b) x (a x b) you now have created an F2 generation. (we'll call these "c") In the F2 generation you find expressions of ALL parental material involved. This means that the plants show expressions of not only a and b, but also the parents that were used to make a and b. So this technically means the grand parents. For the example lets say that "a" was created using (g x h) and "b" was created using (y x z). So in the F2 generation you are going to see expression of (a x b) and also expression of (a x g, a x h, a x y, and a x z) also (b x g, b x h, b x y, b x z) NOW, each one of these plants in the F2 generation is going to recombine in any number of ways. Meaning a plant could be 10% "a" x 90% "b" or eve 50% "a" x (30% "b" x 20% "z").
Basically, the F2 generation makes available, if enough seeds are sprouted, EVERY POSSIBLE recombination of genetics that exist within the line...not just the mother and father, but also the grandparents, the great grandparents...etc. This is why plants that are poly-hybrid (consisting of 3 or more genetic lines) are nearly impossible to isolate for given traits and why it takes soooo very long to do a proper breeding project, where the goal is to have a seed line that is consistent for a single or set of desired attributes.
Remember earlier I mention we would call the F2 line "c". So when breeding (c x c), or the F2 line together, you are taken to the F3 generation. IF the selected parents from the F2 line shared known or desirable traits, then the F3 line should be MORE consistent for producing these selected traits...however, there are still going to be traces from the grandparents, or whatever else might have been set free when making the F2 line.
It is to be understood that when people on forums make their own seeds and call them "F2" generation, that may not be entirely accurate. It is assuming that the breeder they bought them from never developed a line past the (a x b) initial cross, or F1 generation. This is HIGHLY unlikely that a breeder would release such a line. MOST offerings made by hobby breeders label as "F2" should be understood as...one generation from the breeders stock. Meaning the breeder has possibly taken the line to f6 or f7, but to designate the seeds the hobbyist made as being from original breeder stock, we call them F2. This is why in most cases, you see some breeders and hobbyist, calling something an Ix, or incross. An incross is MORE accurate a description when you make more beans from a known breeders seed line, because it doesn't suggest what generation the seeds are, but simply that it was, for example blueberry x blueberry, with both parents coming from the same breeding stock.
NOW THEN Moving forward and to start a new confusion of letters...hahaha. These letters no longer correlate to the above one...hahaha...to explain what Mosca has done with his C99 and to answer your question.
One of the BIGGEST reasons that C99 was SOOO loved and declared a "holy grail" was because it was relatively TRUE breeding. Meaning that when you took Grimm F1's (a) and bred them together (a x a) your F2 generation actually produced a DRASTIC number of plants that actually looked IDENTICAL to a. Which is VERY unusual, as I just explained. This trait is known as true breeding, and for whatever reason, Bros Grimm hit the nail on the head with c99. It has ALWAYS been a relatively true breeding genetic line. How cool is that? So breeders, professional and alike ate it up. Now, keep in mind that original c99 while being considered true breeding DID express two main phenotypes. A more common grapefruit pheno and a lesser but still very common pineapple pheno. These 2 phenotypes were still just as consistently found, in ratio, in the F2 generations, still making possible to categorize it as relatively true breeding.
Reeferman, grew his C99 from Grimm stock. He selected his plants for the higher yielding, denser, larger colas, fruitier, grapefruit expressions within the C99 line. He breed this line many generations to make his seed lines consistent for those given traits he loved. He breed it to a point of what is known as an IBL (inbred line, which essentially designates something as true breeding) Now, how is this possible if c99 was ALREADY true breeding...???!!! REMEMBER, I said relatively. He created a line of c99 that was true breeding for the grapefruit traits / phenos and for the most part worked out the pineapple phenos because it was his choice and his prerogative.
Now WallyDuck took original Bros Grimm c99 in a different direction. He enjoyed the pineapple, more sativa expression of the c99 line. It was a different flavor, had smaller buds over all, a bit more spicy, grew a bit different in structure. It was a different pheno he chose to focus on. Now Wally took his c99 multiple generations and breed it to a point of consistency and IBL status. (usually F6 and beyond can start to be considered IBL IF, IF, IF the breeder made proper selections) His seeds grew plants that consistently represented the traits he had selected for.
Now here comes Mosca. He took what is essentially two separate IBL lines of C99, Reefs and Wallys, although originating from both Grimm stock original parents, they had been breed for so many generations in essentially a different direction. One breeder had perfected and isolated one set of given traits, and another breeder has isolated and perfected the other set of given traits. What you are looking at is BOTH phenotypical expressions of c99 separated to IBL status...and then RECOMBINED to a line that once again will have expressions of BOTH plants...ala, a solid recombination of all traits that the original Bros Grimm c99 was known to have expressed. In my opinion, this was nothing short of sheer brilliance for Mosca to recognizes this and see the potential that was held within both lines...and to realize what could be gained by once again bringing them back together.
IS Mosca's c99 a TRUE F1...well, yes and no. It is technically an IBL x IBL...which when breed in laymans terms seems to be an F6 x F6 (don't quote this...is is merely example, I am not certain how far each breeder, meaning Reef/Wally, took their lines, so it could be an F5 X F7 or F6 X F5...not sure...but I know they both took them many generations. I will use F6 just as a figurative representation that both lines have been heavily worked) Anyway...in laymans terms, it seems to be an F6 x F6 which doesn't = F1, now does it? WELL, actually and technically, maybe not. BUT, BUT...IT DOES. The reason for this being, is that it is the MOST accurate way to describe what Mosca did. He took two plants that are IBL for separate traits, and combined them. This would be no different than taking Pine Tar Kush (a known IBL) x Skunk #1 (another IBL). The result of this WOULD be a TRUE F1, simply because it is the first recombination of two separate, pure, true breeding lines. WELL, that is EXACTLY what Mosca has done with his c99. He has taken two separate, true breeding IBL's, and recombined them for a first generation of seed...this, my friends, IS most accurately described and labeled as an F1. So while it takes a bit of understand and some time to wrap ones head around the concept...I think Mosca is 100% correct in his naming scheme.
The only reason I stand behind this, is because it took me quite a bit of time and research to verify and understand this claim myself...but once I did the study...It was without a doubt, the most accurate way to name this seed line. And what he gave us, was an awesome plant that has once again united all the known and beloved traits of the original Bros Grim C99.
Like I said, personally, once I understood it, I found it to be VERY clever and and intelligent breeding strategy.
dank.Frank
