Registration of BTx623_dw5, a New Sorghum Dwarf Mutant

Abstract

The USDA-ARS has released a new dwarf sorghum [Sorghum bicolor (L.) Moench) mutant BTx623 dw5 (Reg. No. GS-787, PI 688506). Dwarf genes have been an important driving force in breeding since the Green Revolution. Single dwarf locus is used to breed high-yielding semidwarf wheat (Triticum aestivum L.) and rice (Oryza sativa L.) cultivars. However, in sorghum, any of the known dwarf loci alone are insuicient to breed semidwarf grain sorghum itting for modern farm practices. Therefore, four dwarf loci have been traditionally used collectively in combinations to breed sorghum cultivars of the desired plant height for machine harvesting. Here we register a new sorghum dwarf mutant isolated from a mutagenized BTx623 mutant library, which is genetically diferent from those currently known controlling the dwarf phenotype in sorghum. Therefore, we designated this newly identiied dwarf genotype as dwarf 5 (dw5). The dwarf phenotype of dw5 was evaluated in two environments: the Puerto Rico winter nursery with short days and mild temperature conditions and the Lubbock, TX, summer ield with long days and high temperature conditions. The dw5 mutation reduced the plant height of BTx623 from 155 to 74 cm in Puerto Rico and from 113 to 72 cm in Lubbock. The dwarf phenotype in dw5 mutant is caused by a single nuclear gene mutation and is inherited in a recessive manner. It can be easily identiied and bred into other sorghum lines through recurrent backcrossing. The dw5 mutation provides a new way to control sorghum height.

Genome-Wide Association Study for Biomass Related Traits in a Panel of Sorghum bicolor and S. bicolor × S. halepense Populations

“…So far, three of them have been isolated and cloned: Dw1 (Sobic.009G230800) encodes for a putative membrane protein involved in the regulation of cell proliferation in the internodes (Hilley et al, 2016;Yamaguchi et al, 2016); the product of Dw2 (Sobic.006G067600) is a protein kinase regulating stem internode length; and Dw3 (Sobic.007G163800), which was the first to be identified, encodes a phosphoglycoprotein of the adenosine triphosphatebinding cassette (ABC) transporter superfamily involved in auxin transport, orthologous to maize br2 (Multani et al, 2003). Although Dw1-Dw4 explain most of the observed phenotypic variability for sorghum plant height, the existence of a fifth Dw gene (Dw5) has been recently reported (Chen et al, 2019); additionally, a number of other genes involved in gibberellin and brassinosteroid metabolism have been identified which can directly affect plant height (Ordonio et al, 2016b).…”

Genome-wide analyses using multi-locus models revealed marker-trait associations for major agronomic traits in Sorghum bicolor

“…Dw4 has been mapped to chromosome 4 (Li et al, 2015), but the gene behind this locus has not been identified yet. Additionally, a fifth dwarfing locus (Dw5) has recently been reported (Chen et al, 2019).…”

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.…”