Building resilient crops: A comprehensive review of gene pyramiding for durable resistance and multi-stress tolerance

Abstract

Gene pyramiding represents a fundamental paradigm shift in modern crop improvement, empowering breeders to transcend the limitations of single trait selection by synchronizing the simultaneous integration of multiple elite alleles into superior, multi stress tolerant cultivars. This strategy is no longer a luxury but a mandate; as global yield trajectories falter against the projected necessity to double food production by 2050, the stability of our food systems is increasingly besieged by a synergistic onslaught of virulent biotic pathogens and volatile abiotic stressors. Leveraging the precision of Marker-Assisted Selection (MAS), contemporary breeding programs can now stack numerous genes or complex Quantitative Trait Loci (QTLs) with accuracy, ensuring the rapid recovery of the elite recurrent parent genome while minimizing the deleterious effects of linkage drag. This strategic consolidation of genetic assets not only reinforce immediate phenotypic performance but also provides a critical biological buffer against the evolution of pathogen virulence, thereby enhancing the durability of resistance in the field. This review synthesizes the current landscape of gene pyramiding, examining the biological mechanisms that underpin multi genic durability. Furthermore, it explores the integration of transformative molecular technologies most notably CRISPR-Cas9 mediated genome editing and Genomic Selection (GS) to bypass the logistical bottlenecks of traditional breeding.