Sorghum is an economically important food security crop primarily cultivated by small-scale farmers in Sub-Saharan Africa. However, sorghum production is severely constrained by Striga hermonthica, a root-parasitic weed. In Ethiopia, yield losses in heavily infested fields can reach 100%. Therefore, the continuous identification and pyramiding of beneficial genes for Striga resistance is a widely recognized and effective strategy to mitigate this problem. We analyzed 318 Ethiopian sorghum landraces to identify quantitative trait nucleotides (QTNs) significantly associated with Striga resistance indices and subsequently discovered potential candidate genes. Based on three Striga resistance indices, 25 landraces exhibited greater resistance than the resistant check variety, Berhan. The most resistant landraces included ETSL₁00874, ETSL₁01451, ETSL₁01210, ETSL₁00275, ETSL₁00494, IS₃8279, and ETSL₁01258. A genome-wide association study (GWAS) identified 36 significant QTNs associated with the three Striga resistance indices. In the sorghum genome, 33 potential candidate genes are located near 17 strongly associated and reliable QTNs. The candidate genes are likely involved in various resistance mechanisms, including the production of low-germination stimulants, initiation of a hypersensitive response, antibiosis, formation of physical barriers, immunity, root system architecture, photosynthetic efficiency of the host plant, and activation of defense-related genes. These findings provide evidence of existing Striga resistance sources within the local collection. Overall, this study advances our understanding of the genetic architecture of Striga resistance and can facilitate marker-assisted selection to enhance the efficiency of Striga resistance breeding programs in sorghum, thereby accelerating the development of durable Striga-resistant sorghum varieties for small-scale farmers.
Legesse et al. (Sat,) studied this question.