Registration of three new bmr12 sorghum mutants from an ethyl methane sulfonate–induced BTx623 mutant population

Abstract

Three new sorghum (Sorghum bicolor L.) brown midrib (bmr) genetic stocks BTx623bmr12-30 (Reg. no. GS-790, PI 699404), PI 699405), PI 699406) were developed for release by USDA-ARS in Lubbock, TX. The primary purpose for the release of these stocks is to provide an extensive source of (bmr12) variants for use in forage breeding programs. The genetic stocks were isolated from the pedigreed sorghum ethyl methane sulfonate-mutagenized sorghum in BTx623 background. The derived mutations were analyzed by DNA sequencing and confirmed by KASP (Kompetitive Allele Specific PCR) markers. The confirmed bmr mutants were also analyzed for stem and leaf lignin and carbohydrate contents. Furthermore, physiological and agro-morphological evaluations were performed under control and field conditions.All genetic stocks displayed the reddish-brown pigmentation in the leaf midrib, confirming the bmr phenotype. The bmr12 mutants flowered 4-5 d earlier than the wild type BTx623. Physical and compositional characterization of seeds from the three genetic stocks revealed no negative consequence of bmr on grain structure. Notably, these bmr12 mutants had 14-24% greater total seed protein than wild type BTx623.The three new bmr12 alleles provide public and private breeders crucial and novel genetic stock sources for use in breeding bmr forage sorghum.

Registration of 252 sequenced sorghum mutants as a community reverse genetic resource

“…In addition to the wide range of morphological phenotypes, several mutated traits with potential agronomic applications have been isolated from the mutant library. These traits include multiseeded ( msd ) mutants that have panicles with increased seed number and sink capacity (Burow et al., 2014; Dampanaboina et al., 2019; Gladman et al., 2019; Jiao et al., 2018), erect leaf ( erl ) mutants to modify canopy structure (Xin et al., 2015), novel dwarf ( dwf ) mutants for breeding semi‐dwarf varieties (Chen et al., 2019b), brown midrib ( bmr ) mutants for increasing forage and biomass quality (Emendack et al., 2022; Saballos et al., 2012; Sattler et al., 2012, 2014; Scully et al., 2016; Tetreault et al., 2021), and nuclear male sterile mutants ( ms ) for developing novel breeding system (Chen et al., 2019a; Xin et al., 2018, 2017). This resource can help researchers find mutations in their genes of interest online and subsequently characterize the effect of the mutations on the function of those genes.…”