Genetics and phenotypes

A genotype is the genetic code a plant carries. A phenotype is what that code produces once the environment has had its say. Two seeds from the same pod share parents but not code, in the same way two siblings do. Two cuttings from the same plant share code exactly.

This is the whole reason clones exist. A cut taken from a selected plant will express the same genotype indefinitely, subject to how well you keep it. A seed will not. If you want the plant you had last year, you needed to keep a mother.

Breeders use a small set of generation terms. They describe how a cross was made, and they carry more information than the name does.

• —F1 — the first cross between two distinct parents. Individual F1 plants are genetically varied, but if both parents were themselves stable and unrelated, the offspring are often noticeably uniform. Most commercial cannabis called F1 does not meet that condition.
• —F2 — two F1 siblings crossed. This is where variation opens up, because the traits the F1 generation held together now segregate. Large F2 populations are where selection work actually happens.
• —Backcross, BX — offspring crossed back to one parent to concentrate that parent's traits. BX2 and BX3 mean it was done repeatedly.
• —IBL — an inbred line, selfed or sibling-crossed for enough generations that the population runs true for the traits selected. Genuinely stable lines are uncommon and take years.
• —S1 — the offspring of a plant pollinated with its own reversed pollen. All female, and closer to the parent than a cross, but not a clone and not free of the parent's recessive problems.

Nearly everything sold today sits many generations deep into crosses of crosses. A lineage line on a pack often reads as three or four named hybrids, each of which is itself a hybrid. Nobody has stabilised that. What you have is a population with a wide range of possible outcomes, some of which look like the photographs and some of which do not.

That is not a criticism. Polyhybrid populations are where new material comes from. It does mean that buying a pack is buying a lottery with a described prize pool, not buying a product with a specification, and a breeder who is honest about variation is telling you something useful.

Feminized seed is made by chemically reversing a female plant so it produces pollen, usually with silver thiosulfate solution or colloidal silver, then using that pollen on a female. Because no male genetics are involved, the offspring are female except for rare failures. Reversal does not create hermaphroditism as an inherited trait by itself, but a line that reverses easily under stress is a line that will throw bananas in your tent, and that tendency is heritable.

Autoflowering comes from a day-neutral flowering trait carried by ruderalis populations. It is recessive, which is why crossing an autoflower to a photoperiod plant produces photoperiod F1 offspring, and why breeders have to go to F2 and beyond to recover the autoflowering trait in a new cross. Modern autoflowers have closed much of the old potency and yield gap, but they will not wait for you. The plant runs on its own clock, so a check in week three cannot be undone in week five.

Hunting is the process of growing a population, selecting the individual you want, and keeping it. It is not complicated, but it is arithmetic. If a desirable phenotype appears in roughly one plant in twenty, popping five seeds is not a hunt.

A workable process looks like this.

• —Grow enough plants that the rare outcome has a chance to appear. Serious hunts run dozens, not a handful.
• —Decide the selection criteria before you start, and write them down. Structure, flowering time, aroma, yield, resistance, how it behaves under your specific conditions.
• —Keep a clone of every candidate in veg before you flower the mothers, or the winner is gone when you find it.
• —Run the finalists again. A plant grown once has been tested once, and a single run cannot separate the genotype from the conditions it happened to get.
• —Keep records per plant, not per tent. Without them you are selecting on memory.

NoteA selection is only valid for your room. A plant that wins in a small tent under one light may lose badly in a different environment, which is part of why grower reports disagree so often.

There is no registry enforcing cannabis cultivar names. Any breeder can release something called Gelato, and several have, from different parents and different selections. Two packs with identical names can share no recent ancestry at all.

This is the reason this database is organised by breeder rather than by name. A row here belongs to the breeder that bred it, carries the specifications that breeder published, and links back to the page those figures were read from. If you want to compare two versions of a name, compare the breeders.

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