Genetic progress achieved over ninety-three years of sunflower breeding in Argentina, 1931–2024

Abstract

Context

Genetic gain studies addressing parts of the history of sunflower breeding in Argentina (1931–2024) have been published, but many gaps remain.

Objective

To fill all gaps in the quantification of sunflower genetic progress in Argentina.

Methods

A multi-environment dataset of 1074 field trials (1935–2023) was analyzed using linear models, regression, and self-organizing maps (SOM) in the context provided by historical production periods.

Results

Open pollinated variety (OPV) breeding (1938–1990) did not produce significant yield progress but shortened maturity, increased oil concentration, improved agronomics and contributed to building a locally adapted genetic pool. Hybrids that replaced OPVs (1970–1990) showed earlier maturity and higher values for oil yield and its immediate determinants. Genetic gains estimated for the period 1953–2022 were −0.15 % yr⁻¹, 0.72 % yr⁻¹, 0.46 % yr⁻¹ and 1.49 % yr⁻¹ for time to flowering, grain yield, oil concentration and oil yield, respectively. A slowdown in genetic progress was observed starting in the mid-1990s, associated with crop displacement, pathogen and pest evolution, and linkage drag shown by early herbicide-resistant hybrids.

Conclusions

Sunflower breeding programs of Argentina consistently released superior genotypes at rates of genetic gain that are comparable to larger, better resourced crop growing systems.

Significance

A dataset spanning all breeding periods, growing areas and relevant cultivars allowed us to fill all gaps in describing breeding contributions to sunflower yield progress in Argentina. We also proposed the use of SOMs to estimate the impact of individual cultivars on the genetic gain achieved by a crop growing system in different historical periods.