Wild species and landraces of sorghum for biotic and abiotic stress resilience: Opportunities and future prospects

Abstract

Intensive domestication and continuous selection have substantially narrowed the genetic diversity of cultivated sorghum (Sorghum bicolor (L.) Moench), limiting its adaptive capacity to emerging biotic and abiotic stresses associated with climate change. Crop wild relatives (CWRs) and traditional landraces represent valuable reservoirs of novel alleles for enhancing stress resilience, biofortification and forage traits. This review synthesises current knowledge on the diversity and utilisation of sorghum wild species and landraces, highlighting the contribution of primary, secondary and tertiary gene pools to crop improvement. Particular emphasis is placed on identifying genetic resources conferring resistance to major biotic stresses, including shoot fly, stem borer, anthracnose, downy mildew, grain mould and Striga, as well as tolerance to drought, heat, salinity, cold, flooding and nutrient stress. The review also summarises recent advances in molecular breeding and genomic tools, including marker-assisted selection, genome-wide association studies (GWAS), genomic selection, pre-breeding and CRISPR/Cas-based genome editing, which facilitate the efficient introgression of beneficial alleles from wild germplasm into elite cultivars. Furthermore, the potential of wild species and landraces for biofortification and forage quality improvement is discussed. Harnessing these underutilised genetic resources will broaden the genetic base of cultivated sorghum and accelerate the development of climate-resilient, nutrient-rich and high-yielding cultivars, thereby contributing to sustainable agriculture and global food security.