A global resource for exploring and exploiting genetic variation in sorghum crop wild relatives. Issue 1 (11th December 2020) - Mace, Emma S.
Abstract: One response to mitigate the impact of climate change on agricultural systems is to develop new varieties that are tolerant to the new range of biotic and abiotic challenges this change causes. This requires access to novel variants of genes for complex adaptive traits. Crop wild relatives (CWRs) are a potentially valuable source of these genes; however, these materials are often difficult to work with and identifying valuable alleles is difficult without substantial investment in prebreeding. In this study, we describe the development of a nested association mapping population for sorghum [ Sorghum bicolor (L.) Moench] using two cultivated grain sorghum reference parents and nine wild and exotic sorghum accessions as donors. The donor parents come from the S. bicolor (L.) Moench subsp. verticilliflorum (Steud.) de Wet ex Wiersema & J. Dahlb., S. bicolor (L.) Moench subsp. drummondii (Steud.) de Wet ex Davidse, and S. bicolor (L.) Moench subsp. bicolor margaritiferum taxa and were sampled from a range of environments across Africa. In total, the resource consists of 13 populations and a total of 1, 224 lines. The population has been genotyped with diversity array technology (DArT) markers that produced 42, 372 unique single nucleotide polymorphism (SNP) markers covering the genome. We determine the utility of the resource for high resolution mapping of complex traits by demonstrating that the exotics contain unique alleles for some example adaptive trait loci and by using the population for genome‐wide association study (GWAS). The resource should provide useful material for plant breeders attempting to deal with the challenges generated by climate change. Core Ideas: A novel nested association mapping population based on sorghum wild relatives is described. The novel resource developed is suitable for GWAS trait dissection activities. The resource provides useful alleles for breeding germplasm adapting to climate change.