Dimitri Sanchez, Antoine Allier, Sarah Ben Sadoun, Tristan Mary‑Huard, Cyril Bauland,Carine Palafre, Bernard Lagardère, Delphine Madur, Valérie Combes, Stéphane Melkior, Laurent Bettinger, Alain Murigneux, Laurence Moreau, Alain Charcosset

Theoretical and Applied Genetics; January 2024; vol. 137; Article 19

Key message

Implementing a collaborative pre-breeding multi-parental population efciently identifes promising donor x elite pairs to enrich the fint maize elite germplasm.

Abstract

Genetic diversity is crucial for maintaining genetic gains and ensuring breeding programs’ long-term success. In a closed breeding program, selection inevitably leads to a loss of genetic diversity. While managing diversity can delay this loss, introducing external sources of diversity is necessary to bring back favorable genetic variation. Genetic resources exhibit greater diversity than elite materials, but their lower performance levels hinder their use. This is the case for European fint maize, for which elite germplasm has incorporated only a limited portion of the diversity available in landraces. To enrich the diversity of this elite genetic pool, we established an original cooperative maize bridging population that involves crosses between private elite materials and diversity donors to create improved genotypes that will facilitate the incorporation of original favorable variations. Twenty donor × elite BC1S2 families were created and phenotyped for hybrid value for yield related traits. Crosses showed contrasted means and variances and therefore contrasted potential in terms of selection as measured by their usefulness criterion (UC). Average expected mean performance gain over the initial elite material was 5%. The most promising donor for each elite line was identifed. Results also suggest that one more generation, i.e., 3 in total, of crossing to the elite is required to fully exploit the potential of a donor. Altogether, our results support the usefulness of incorporating genetic resources into elite fint

See https://link.springer.com/article/10.1007/s00122-023-04509-5

Figure 3: Variance decomposition with the model M_FG_S and within-family genetic variance estimation for each trait. For each family, genetic (in dark green) and G × E (in shades of light green) variances are showed. Error term variances are also displayed (in shades of pink). For comparison, variances estimated with the models M_G and M_FG are presented on the right part of each graph with the same color code (color figure online)