Using probe genotypes to dissect QTL × environment interactions for grain yield components in winter wheat.

Area of Science:

• Plant Genetics and Breeding
• Agricultural Science
• Quantitative Genetics

Background:

• Wheat yield is a complex trait influenced by genotype × environment interactions (QEI).
• Understanding QEI is crucial for developing wheat varieties adapted to diverse environmental conditions, especially under limited resources.
• Identifying specific genomic regions (quantitative trait loci, QTL) involved in QEI is a key objective.

Purpose of the Study:

• To identify genomic regions (QTL) associated with QEI for wheat yield components: kernel number (KN) and thousand-kernel weight (TKW).
• To develop a strategy for understanding the environmental specificity of these QTL.
• To analyze the influence of environmental covariates on QEI for KN and TKW.

Main Methods:

• A doubled-haploid wheat population (Arche × Récital) was evaluated across 12 environments (varying locations, years, and nitrogen levels).
• QTL analysis was performed for KN and TKW in each environment.
• Factorial regression was used to estimate genotypic sensitivities to environmental covariates and detect QTL for these sensitivities.

Main Results:

• A total of 131 QTL were identified for KN, TKW, and their environmental sensitivities.
• Four pleiotropic QTL on linkage groups 1B, 2D1, 4B, and 5A1 affected both KN and TKW.
• Environmental covariates like radiation, temperature, and nitrogen stress significantly explained QEI for KN, while water deficit and temperature explained QEI for TKW.

Conclusions:

• Specific QTL influence wheat yield components (KN, TKW) and interact with environmental factors.
• The identified environmental covariates provide insights into the specificity of QTL effects.
• Focusing on common QTL across different genetic backgrounds can advance understanding of genotype × environment interactions in wheat.