That is a very complex and difficult feat, 'puffa.
It takes several generations of trials, selections, back crossing and inbreeding for "selected" qualities. It is 'nearly impossible with only a small facility. One really needs to be able to grow and select from several(possibly 100's), of both maternal and paternal varieties/phenotypes.
Select, cross, grow/test, more selection, more crossing, more grow/test, ..yet more select, cross, ect. ect. untill "ALL" of the seeds produced grow plants that carry the same characteristics.
If you go to the "Resources" page, scroll down to the breeding section and read, it wil give you a ..very basic...understanding.
...i'm not too bright
...lol.
