Stabilisation is the work of taking a variable seed population and breeding it, generation by generation, until its seed reproduces the chosen traits reliably. Genetically, it means making the line homozygous at the loci behind those traits while culling defects along the way.
In practice
A typical route: make an F1, grow a large F2, select the plants closest to the target, cross them (sib crossing), and repeat for F3, F4, F5 and beyond. Backcrossing to a key parent or a few generations of careful selfing can speed it up. Each round needs enough plants to see what is still segregating, and strict culling for herms and weakness.
A line is "stable" for the traits that were selected and measured, not for everything. Ask what was stabilised: chemotype, flowering time, structure, aroma? How many plants were grown in the last generation, and what was the herm rate?
Don't confuse with
- A named cross: a single F1 of two hybrids is not stabilised, whatever the pack says.
- Uniformity: a line can look uniform in one room and still segregate for traits not tested.
- Clone-only: a single genotype, perfectly stable as cuttings but not in seed form.
Myth check
"Stable" without generation records and tester-grow data is a marketing word. See backcrossing, IBLs and stabilisation.
A plant is homozygous at a locus when it carries two identical alleles there (AA or aa), so it passes the same allele to every offspring.F1 is the first generation of offspring from crossing two parents; if the parents are inbred and different, F1 plants are uniform and often show hybrid vigour.F2 is the second filial generation, made by crossing or selfing F1 plants; it shows the widest segregation, bringing back hidden recessives and new combinations.Filial generations (F1, F2, F3 and on) count generations of offspring from an original cross, each made by crossing plants of the previous generation together.A backcross is a cross of a hybrid back to one of its parents (or that parent's line), repeated to recover the parent's traits while keeping one introduced trait.Segregation is the separation of a plant's two alleles at each locus into different gametes, so offspring of a heterozygous parent vary in which allele they get.The herm threshold is GenetixBay's two-tier herm standard: a 10-plant screening grow with zero herms to be featured, then about 150 or more community-grown plants before a line can be Verified under 2% herm rate.A hybrid is the offspring of two genetically different parents; almost all modern cannabis is hybrid, built from crosses between landrace-derived and other lines.An IBL (inbred line) is a seed line that has been inbred and selected over many generations until it breeds true for its main traits, giving uniform offspring.A true-breeding line produces offspring that consistently look like the parents for a given trait, because the plants are homozygous for the alleles behind it.Uniformity is how alike the plants of one seed batch are for traits such as height, timing and chemistry; F1s of inbred parents and IBLs are most uniform.
