From lab to field: accelerated cultivar release via integrated speed breeding framework in wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) breeding must accelerate to meet increasing global demand, yet traditional field-based programs remain a major bottleneck. While speed breeding (SB) and speed vernalization (SV) have emerged as transformative tools for generation acceleration, their practical application for official cultivar release through comprehensive field validation remains remarkably limited.

We developed the new high-yielding bread wheat cultivar ‘Irum’ using an integrated speed breeding (ISB) system that combines SV with SB protocols. The ISB system facilitated the rapid advancement of F₁ to F₅ generations within only 15 months, effectively reducing the total breeding cycle from 128 months to 80 months, representing a significant 4-year reduction. Principal component analysis confirmed that the ISB-advanced population maintained the trait diversity required for effective selection, allowing for the strategic identification of elite lines. Multi-year and multi-environment field trials demonstrated that ‘Irum’ exhibited a consistent agronomic performance across environments, achieving a significant 14.6% yield increase over the check cultivar ‘Keumgang’. Furthermore, ‘Irum’ exhibited enhanced bread-making quality, producing a significantly larger loaf volume and lower crumb firmness than the high-quality check ‘Baekkang’.

As the first official cultivar released through the ISB system in South Korea, to our knowledge, ‘Irum’ demonstrates a successful ‘lab-to-field’ transition and provides a robust, high-efficiency framework for rapidly delivering high-performance cultivars to the wheat industry.