View Program - 2022 Population, Evolutionary, and Quantitative Genetics Conference

Targeted recombination refers to the occurrence of recombination at a specific genomic position. Such concept has been recently applied to crop breeding and has revealed to be promising for the improvement of quantitative traits. Meanwhile, in a breeding program, traits of interest are frequently scored in ordinal scales, such as disease resistance. However, no studies have investigated whether targeted recombination can be applied to the improvement of ordinal traits. Therefore, the objectives of this study were to use simulated and empirical data: (1) to determine whether the strategy of targeted recombination can be applied to the improvement of ordinal traits, (2) to identify factors influencing on the breeding efficiency of targeted recombination in ordinal traits, (3) to compare the relative efficiency of genotypes carrying targeted recombination estimated based on ordinal data and its compatible continuous data. Our results showed that targeted recombination could effectively improve ordinal traits under various genetic architectures. A bi-parental cross of ca. 150 progenies scored with a five-category scale suffices for marker effect estimation and target site determination. The relative efficiency between targeted recombined genotypes estimated based on ordinal traits and their quantitative counterpart were comparable. Hence, our study suggested that targeted recombination be applied to the improvement of ordinal traits with a similar efficiency of continuous trait.

Evaluate Breeding Efficiency of Targeted Recombination for Ordinal Traits