Selfing is fertilising a plant with its own pollen. Cannabis is dioecious, so a female does not normally make pollen; breeders induce it by treating a branch or a clone of the same female with silver thiosulfate (sex reversal). The seed is called S1.
In practice
Selfing halves heterozygosity in one generation (F = 0.5), so it brings out hidden recessives quickly and can show what a clone carries. It is a fast diagnostic and a last-resort way to keep something of a clone in seed form.
It is also one of the main routes to herm-prone lines. Selfing a plant that has already shown intersex flowers, stacking S1 on S1, or releasing selfed seed without growing it out and culling, all spread instability.
Don't confuse with
- S1: the seed produced by selfing.
- Feminised seed: any seed made with reversed female pollen; selfed seed is feminised, but feminised seed is often a cross between two different females.
- Hermaphrodite pollination: accidental selfing by a herm in the room, which also selects for the herm trait.
Myth check
House position: selfing is mostly frowned upon on GenetixBay. Historically it was an emergency measure to save a line, not a breeding method. Real breeding uses real, selected males, and males are encouraged and rewarded here. Only ever self a proven-stable female, then cull every intersex offspring. See S1s and selfing.
STS (silver thiosulfate) is a silver compound sprayed on female cannabis to block ethylene action and induce fertile male flowers, the standard method for making feminised seed.Sex reversal is chemically inducing a genetically female cannabis plant to grow fertile male flowers, so its pollen can make feminised seed; silver thiosulfate is the standard agent.S1 is seed from a plant pollinated with its own pollen; every S1 seed is female and a new genotype, not a copy of the parent.A plant is heterozygous at a locus when it carries two different alleles there (Aa), so its offspring can inherit either one and segregate.A recessive allele only shows its effect when a plant carries two copies of it; in a single copy it is masked by a dominant allele and carried silently.Herm-prone describes a line whose plants often produce intersex flowers; GenetixBay treats this as a breeding fault and a reason not to breed from it.In cannabis growing, a plant (usually female) that develops both pistillate and staminate flowers or anthers; botanists call it intersex or monoecious expression.Feminised seed is seed made by pollinating a female with pollen from another female (or itself) that was chemically reversed, so nearly every seed grows into a female.Inbreeding depression is the loss of vigour, fertility, yield or survival that follows mating between relatives, mainly because harmful recessive alleles become homozygous.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.
