F1 • BX • IBL • S1 • R1 — What They Mean and Why They Matter

🔹 F1 – First Filial Generation

Definition:

✅ A true F1 is a cross between two cultivars with no shared lineage.

This means both parent lines must be genetically distinct and unrelated — something that’s only possible these days with 100% verified sourcing or true landrace genetics.

✅ F1s are prized for:

• Hybrid vigor (faster growth, higher yield)
• And like a box of chocolates — you don’t know what you’re going to get.

🧬 Example: Northern Lights × The Hog = F1

⚠️ Important Note on “F1s” in Cannabis:

In the cannabis community, the term “F1” is often misused. Many so-called “F1” seeds sold online are actually polyhybrids — crosses of other hybrids — and do not meet the strict genetic definition of an F1.

➡️ True F1s come only from two stable, inbred parent lines.

Unless both parents are genetically isolated and consistent, it’s not a real F1.

A cross with any common lineage is a polyhybrid.

🔹 BX – Backcross

Definition:

BX (Backcross) means crossing a hybrid offspring back to one of its original parents to reinforce specific traits.

✅ Used for:

• Stabilizing desired characteristics
• Preserving clone-only genetics

🧬 Example: F1 × Parent A = BX1

BX1 × Parent A = BX2, and so on

💡 Clone-Only to Regular Seed Strategy:

If you want to make regular seeds from a clone-only plant, cross it with a similar regular cultivar first. Then backcross the offspring to the original clone through multiple cycles (BX1, BX2, BX3) to lock in traits.

🔹 IBL – Inbred Line

Definition:

IBL (Inbred Line) refers to a genetically pure, stabilized line, created through selective inbreeding over multiple generations.

It is used to preserve rare, landrace, or legacy seed stock, and to increase seed quantity without diluting the original genetics.

✅ Two Primary Goals of IBL Work:

1. Preserve Original Genetics – Taking old or rare seed stock and carefully breeding to maintain the original traits.
   
2. Expand Seed Supply Without Dilution – Increasing seeds while ensuring the line stays genetically true.

✅ Benefits:

• Highly consistent traits (structure, timing, aroma)
• Very low variation
• Ideal for preservation, breeding, or genetic cataloging

⚠️ Note:

True IBLs are rare. Most seed lines today are polyhybrids with wide variation.

🔹 S1 – Selfed Feminized Seeds

Definition:

S1 (Selfed Line 1) seeds are made by reversing a stable female plant and pollinating itself or a clone of itself.

✅ Benefits:

• 100% feminized (no males)
• Offspring closely resemble the mother
• Great for preserving elite clones

🧪 Common Reversal Methods:

• My go-to: ElitexElite
• STS (Silver Thiosulfate)
• Colloidal Silver
• Other ethylene blockers

⚠️ Note:

S1s can expose hidden recessive or herm-prone traits. Always start with a proven stable female.

🔹 R1 – Reversed Feminized Cross

Definition:

R1 seeds are made by reversing a female plant and pollinating a different, unrelated female.

✅ Purpose:

• Feminized seeds with new traits
• Great for crossing clone-only elites
• Useful in feminized hybrid projects

🧬 Example: Reversed GMO × Peanut Butter Breath = R1 Feminized Seeds

⚠️ Note:

R1s often show more variation than S1s. Results depend on both parents’ stability and lineage.
The more shared lineage in the parents, the more pheno diversity you’ll see.