Speed breeding in perennial fruit crops as a novel strategy to reduce generation period

Speed breeding has transformed plant breeding by reducing the generation period of annual crops, yet its potential as a tool to accelerate genetic gain in perennial fruit crops has not been fully explored. Perennial crops including apple and walnuts face a major bottleneck in breeding owing to their extensive juvenile stage, which delays the assessment and selection of desired traits. This review and conceptual framework explore a novel integration of speed breeding with strategic use of early-bearing genotypes as intermediate parents in hybridization programs to expedite cultivars development. In apples, the strategy involves utilizing columnar varieties, while in walnuts, lateral-bearing genotypes are employed to introduce early fruiting traits into elite genetic backgrounds. In addition, speed breeding can be complemented by high throughput phenotyping and precision breeding techniques to increase selection accuracy and maximize genetic gain. By implementing these strategies, breeders can decrease generation period and enhance breeding efficiency as they strive to satisfy the increasing global demands for high-yielding, resilient perennial fruit cultivars. This forward-looking strategy aims to redefine the perennial fruit crop development, ensuring sustainability and productivity while addressing the pressing challenges of climate change and food security.