GERMANY – A recent study conducted by the Leibniz Institute for Food Systems Biology at the Technical University of Munich (LSB) and the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) has revealed that extreme dwarfism in wheat significantly impairs gluten composition, leading to reduced baking quality.
The research focused on the impact of Reduced height (Rht) genes, introduced during the Green Revolution of the 1960s to produce shorter, sturdier wheat plants.
These genes helped increase global wheat yields by minimizing wind damage and optimizing grain filling.
Wheat gluten is composed mainly of two groups of storage proteins: gliadins and glutenins.
Gliadins give the dough stretchiness and softness, while glutenins provide elasticity and strength. A balanced ratio between these proteins is vital for good baking performance.
The study found that common dwarfing genes, such as Rht1 and Rht2, widely used in modern wheat varieties and present in over 70% of global wheat cultivation, have a minimal impact on gluten composition.
However, extreme dwarfing genes such as Rht3 and the combination Rht2+3 led to a decrease in total gluten content and a shift in the gliadin-to-glutenin ratio, resulting in softer doughs that compromise bread volume and texture.
To assess these effects, researchers cultivated four wheat lines: tall wild-type, semi-dwarf, dwarf, and extremely dwarf, over three growing seasons at IPK Gatersleben.
Despite their genetic similarities, the extremely dwarf lines consistently showed lower gluten content and an unfavorable gliadin-to-glutenin ratio.
Interestingly, environmental conditions played a significantly more important role. Warm and humid weather during the 2021 grain-filling phase exacerbated the gliadin dominance, further degrading baking quality.
This finding underscores the complex interplay between genetics and climate in wheat breeding.
Lead researcher Sabrina Geisslitz emphasized that while the Green Revolution’s dwarfing genes were agriculturally transformative, caution is warranted when introducing extreme dwarfism into future wheat varieties.
Aside from baking quality degradation, the higher gliadin content associated with extreme dwarfism may also raise immunoreactive potential, which is relevant for gluten-related health issues like celiac disease.
The findings suggest that while semi-dwarf and dwarf wheat breeds remain suitable for modern agriculture without affecting baking performance, the introduction of extreme dwarfing genes should be approached cautiously in future breeding programs.
The study emphasizes the importance of comprehensive breeding strategies that take into account both genetic and environmental factors.
Additionally, this study refines our understanding of how wheat genetics affects gluten properties and baking quality, emphasizing the combined role of gene selection and environmental conditions in achieving optimal wheat performance and food quality.
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