Backcross Breeding Chapter 14

Abstract

Backcross breeding enables breeders to transfer a desired trait such as a transgene from one variety (donor parent, DP) into the favored genetic background of another (recurrent parent, RP). If the trait of interest is produced by a dominant gene, this process involves four rounds of backcrossing within seven seasons. If the gene is recessive, this process requires more generations of selfing and thus nine or more seasons are needed. The rate at which the DP genes are removed and the RP genes are recovered in the genetic makeup of the plant can be calculated using the number of backcross generations utilized. This rate is dramatically increased with the recent advances in marker technology which allow breeders to control the gene of interest and control the genetic background.