It would take many years to stabilize your strain to give consistent pheno's in seed form. Think of it like breeding animals. Hypothetically speaking, if you had a black dog and a white dog and you wanted a grey dog, you would bread the 2. Some of the offspring will be black and some white, some with spots, and maybe a grey one. If you don't get the grey one you try it again, and again, and again. Eventually you get a male grey dog, so you breed it with a grey female. Some of the offspring may be black or white because of the genetic traits in the gene pool. If the majority of them are black or white it's considered a dominate trait, and you keep going until the recessive (grey) trait becomes a dominate trait. But There will always be those recessive traits there. It may be 10 generations later with consistent grey dogs, then all the sudden there is a black or white dog in the litter.
The same holds true for weed. As growers, say we're growing a strain like GDP. We get a seed pack from a breeder, and to do it right, we pop all the seeds. Keep these as mothers, and flower a clone from each. It's possible that there might not even be a purple flowering plant in the population if the genetics haven't been worked enough. Flower out the mothers that don't exhibit the traits you desire, or otherwise get rid of them (you don't want those phenotypes). Now as a grower you will keep those mothers that exhibit the desired traits and only grow clones from them. As a breeder, say you want the purp from the GDP, but you want the sativa high and diesel smell from the sour D. You'll need males of each strain. This is where it gets tricky, because males, even though they don't produce buds, still carry genes that will effect the female flowers in their crosses. So you have to take multiple clones of the female that exhibits some desired traits, and cross each of them with a different male. Now grow out some mothers from these seeds, and flower the clones and compare the differences to try to isolate the genes given by the father. Once you've found the male that carries the genes you want you start working the recessive traits out. This is where you get into F1's F2's, and so on.. F stands for filial generation. You then proceed to find mothers from the f1, f2, ect generations that are purple sour d. You can back cross, BX, by pollenating a later filial generation with the original father or original mother. And keep working and working and working until the vast majority of the population is purple sour d. At this point you can look at the provided link from
@blake9999 and feminize your genetics, which will still produce random genetics, but far more consistent than feminizing the f1 generation.
Unless you're trying to sell seeds, you're best bet is to simply find a mother plant that exhibits the desired traits and just flower clones from her. It takes many years to stabilize a strain, and a lot more space than most growers have. If you still want to start breeding and want a more in-depth explanation than this, contact someone like
@RM3 who is a breeder. I'm sure there are more breeders than just him on RIU, but he's the only one I know of.
