Lineage Claims and Breeder Attribution: How to Weigh Them

What a lineage claim is

A lineage claim says a cultivar came from crossing named parents, for example "A crossed with B." A breeder attribution says who made the cross. Both are usually statements from breeders, seed sellers or online databases. They are not laboratory results, and a claim repeated on many websites is still one claim unless independent evidence supports it.

Reported lineage vs genetic evidence

Reported lineage comes from people. Genetic evidence comes from reading DNA and comparing samples. The two do not always agree.

A genome-wide study of 81 marijuana and 43 hemp samples found only a moderate correlation between the genetic structure of marijuana strains and their reported sativa and indica ancestry. In some cases, the assigned ancestry strongly disagreed with the genotype data. [1] The authors suggested that inaccurate reported ancestry likely stems from the clandestine nature of cannabis growing and breeding over the past century, and concluded that reported ancestry of some very common strains only partially captures true ancestry. [1]

A second study looked at 30 named strains from dispensaries and donors. It failed to find clear genetic support for the commonly referenced sativa, indica and hybrid types as described in online databases, and found genetic differences among samples of the same strain. [2]

A third study genotyped over 100 samples and found that sativa-labeled and indica-labeled samples were genetically indistinct across the genome. [3]

None of these studies proves that any particular named lineage is false. They show that one should not take a lineage story at face value.

What genetic testing can and cannot do

• It can show how closely samples are related to each other (as both genetic studies above did).
• It can show whether samples sharing a name cluster together. In one study, 6 of 17 name comparisons did not. [1]
• It cannot confirm a breeder's private crossing history when no reference DNA from the original parents exists. The 30-strain authors wrote that there are currently no baseline genotypes for any strains. [2]
• Results describe the samples tested. Sample mix-up cannot always be excluded. [1]

Disputed lineages

A lineage is disputed when readable sources disagree about the parents, the breeder or both. Directory profiles show each claim with its source and label. Because strain names are applied to plants even when seed-grown, and seed lines may not be fully stabilized, disagreement is common. [1][2] We do not choose a winner when the evidence does not.

Weighing a lineage or breeder claim

Questions that help:

1. Who is saying it, and when? A breeder's own statement is more direct than a retelling, but still a claim.
2. Is there independent support? A peer-reviewed genetic study is stronger than repetition across websites.
3. Is the claim tied to a specific sample? "This tested sample is closely related to that one" is stronger than a general story.
4. Does it predict effects? Lineage does not predict effects. Chemistry varies between producers and batches even for the same name. [4]
5. Is a percentage attached? Statements such as "70% sativa" are descriptions of reputed ancestry, not chemical measurements.

Labels used in this library

Breeder attribution is marked verified, reported, disputed or unknown. Lineage claims are marked reported, disputed or genetic evidence. Where we found no readable source, the profile says so, and a profile with fewer than two readable sources for identity and lineage is held back. For the full set of rules see How Cultivar Profiles Work.

Lineage and the indica-sativa story

Many lineage stories lean on the words indica and sativa. The authors of the six-state chemistry study found that those labels do not reliably separate samples by chemical content. [4] The labels may instead track a few aroma compounds controlled by terpene synthase genes. [3] See What Does Indica Mean? and Indica vs Sativa vs Hybrid.

Safety note

A famous parent or breeder does not make a product safer, milder or stronger. Cannabis can cause anxiety, impaired thinking and driving risk regardless of lineage; see Cannabis Adverse Effects, Cannabis Use Disorder and When to Seek Help. In an emergency in the US, call 911; for swallowed cannabis products, US Poison Help is 1-800-222-1222.