Daniel Krenzer, Matthias Frisch, Katrin Beckmann, Tobias Kox, Christian Flachenecker, Amine Abbadi, Rod Snowdon, Eva Herzog

Theoretical and Applied Genetics; January 2024; vol. 137; Article 16

Key message

Simulation planned pre-breeding can increase the efciency of starting a hybrid breeding program.

Abstract

Starting a hybrid breeding program commonly comprises a grouping of the initial germplasm in two pools and subsequent selection on general combining ability. Investigations on pre-breeding steps before starting the selection on general combining ability are not available. Our goals were (1) to use computer simulations on the basis of DNA markers and testcross data to plan crosses that separate genetically two initial germplasm pools of rapeseed, (2) to carry out the planned crosses, and (3) to verify experimentally the pool separation as well as the increase in testcross performance. We designed a crossing program consisting of four cycles of recombination. In each cycle, the experimentally generated material was used to plan the subsequent crossing cycle with computer simulations. After fnishing the crossing program, the initially overlapping pools were clearly separated in principal coordinate plots. Doubled haploid lines derived from the material of crossing cycles 1 and 2 showed an increase in relative testcross performance for yield of about 5% per cycle. We conclude that simulation-designed pre-breeding crossing schemes, that were carried out before the general combining ability-based selection of a newly started hybrid breeding program, can save time and resources, and in addition conserve more of the initial genetic variation than a direct start of a hybrid breeding program with general combining ability-based selection.

See https://link.springer.com/article/10.1007/s00122-023-04519-3

Figure 2: Heatmaps of the MRD (red: MRD=0 and white: MRD=1) between the parental lines ordered by hierarchical clustering. The crosses in recombination step R1 identified as favorable by the target functions ′ (top) and T (bottom) in pool 1 (left) and pool 2 (right) are marked by black dots in the heatmaps