Genotype × environment interaction: trade-offs between the agronomic performance and stability of durum (Triticum turgidum) wheat to stem-rust resistance in Kenya

Front Plant Sci. 2024 Jul 25:15:1427483. doi: 10.3389/fpls.2024.1427483. eCollection 2024.

Abstract

Stem rust significantly threatens durum wheat production, often resulting in substantial yield losses. To better understand resistance mechanisms and the stability of durum lines in stem rust-prone environments, this study evaluated 49 durum genotypes over three seasons at the Kenya Agricultural and Livestock Research Organization in Njoro. Utilizing 7 × 7 alpha lattice design, we assessed adult-plant resistance, monitored disease progression through final disease score (FDS) and area under the disease progress curve (AUDPC), and evaluated agronomic performance. Statistical analyses revealed significant seasonal and genotypic effects on FDS, AUDPC, spike length, and grain yield (p≤0.01; p≤0.001), with important genotype-by-season interactions (p≤0.05; p≤0.001). Broad-sense heritability for AUDPC was high at 0.91 and moderate at 0.35 for kernels per spike, underscoring the genetic basis of these traits. Notably, we observed negative correlations between disease parameters and agronomic traits, suggesting potential trade-offs. GGE biplot analysis singled out the first season (main season of 2019) as crucial for evaluating stem rust resistance and identified several durum lines, such as G45 and G48, as consistently resistant across all conditions. Furthermore, this analysis highlighted G45, G48, G176 and G189 as the highest yielding and most stable lines. The discovery of these resistant and high-performing genotypes is critical for enhancing durum breeding programs, helping to mitigate the impact of stem rust and improve yield stability.

Keywords: agronomic performance; durum wheat; genetic variation; genotype-environment interaction; stem rust.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research received funding from Kenya Agricultural and Livestock Research Organization under the Delivery Genetic Gain in Wheat (DGGW) initiative, which is financed by the Bill and Melinda Gates Foundation and the United Kingdom Department for International Development (DFID). Further financial support was provided by the Accelerating Genetic Gain in Wheat (AGGW) project, funded by the Bill and Melinda Gates Foundation (BMGF), the Foreign and Commonwealth Development Office (FCDO), and the Foundation for Food and Agriculture Research (FFAR).