Bx1 and Bx2: returning to a parent

Bx1 means the hybrid was crossed back to one parent once. Bx2 means twice. Each return piles more of that parent’s alleles into the pack. Scatter drops. So can vigour, if you go too far — that is inbreeding depression, a separate note.

We backcross when a parent is worth returning to. Durban Poison BX2 is the clean worked example in the current notes: two returns to the Scouse Durban cut. Orange Apricot and Strawberry Truffle carry BX1 designations in the archive, but their exact recurrent-parent sequence still needs the original bench record. Black Punch is not recorded as a BX line; its recorded parents are Tropicana Punch × Tropicana Punch, with the generation not formally recorded.

What a Bx is not

A BX label and an F1 label answer different questions. F1 means first filial generation: the first generation produced by the recorded parent pairing. The current archive explicitly lists Jammy Dodgers F1, Lemon Dodgers F1 and Apricot Punch F1. BX describes a return to a parent and should only be used where that return is actually documented.

Lineage on the label should match the archive. If the recurrent parent or generation is missing from the surviving notes, we say that rather than fill the gap with a neat story. Souvenir seed. 18+.