Before revision: Disadvantages Works poorly for quantitative traits Is more restricted for recessive traits In practice, sections of genome from the non-recurrent parents are often still present and can have unwanted traits associated with them For very wide crosses, limited recombination may maintain thousands of ‘alien’ genes within the elite cultivar Many backcrosses are required to produce a new cultivar which can take many years Natural backcrossings York radiate groundsel (Senecio eboracensis) is a naturally occurring hybrid species of Oxford ragwort (Senecio squalidus) and common groundsel (Senecio vulgaris).
After revision: ....Disadvantages Works poorly for quantitative traits Is more restricted for recessive traits In practice, sections of genome from the non-recurrent parents are often still present and can have unwanted traits associated with them For very wide crosses, limited recombination may maintain thousands of ‘alien’ genes within the elite cultivar Many backcrosses are required to produce a new cultivar which can take many years Natural backcrossings York radiate groundsel (Senecio eboracensis) is a naturally occurring hybrid species of Oxford ragwort (Senecio squalidus) and common groundsel (Senecio vulgaris).