Genetics & Breeding
Selfing, Inbreeding & Line Development
Self-fertilization and other forms of inbreeding increase homozygosity over generations while exposing recessive variation and potentially concentrating both desirable and undesirable alleles.
Key concepts
- Selfing changes genotype frequencies and increases homozygosity
- Greater uniformity for some traits does not mean all loci are fixed
- Inbreeding can reveal recessive deleterious combinations
- Selection and population management determine which lineages continue
What to measure or observe
- Track selfed generation labels accurately
- Record vigor, fertility, morphology, and target traits
- Compare multiple siblings rather than only one survivor
- Preserve line identity through seed storage
Common mistakes
- Calling an S1 genetically identical to its parent
- Assuming selfing only makes traits more stable
- Ignoring inbreeding depression
- Dropping records for weak or failed families
Visuals this lesson still needs
- Selfing generation tree
- Homozygosity increase concept
- Recessive-expression diagram
- Line-development record example