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

Authors: Emendack, Yves; Xin, Zhanguo; Hayes, Chad; Burow, Gloria; Sattler, Scott; Bean, Scott; Smolensky, Dmitriy

Submitted to: Journal of Plant Registrations
Publication Type: Germplasm Registration
Publication Acceptance Date: 1/21/2022
Publication Date: 4/11/2022
Citation: Emendack, Y., Xin, Z., Hayes, C.M., Burow, G.B., Sattler, S.E., Bean, S.R., Smolensky, D. 2022. Registration of three new bmr12 sorghum mutants from an ethyl methane sulfonate–induced BTx623 mutant population. Journal of Plant Registrations. 16(2):453-458. https://doi.org/10.1002/plr2.20219.
DOI: https://doi.org/10.1002/plr2.20219

Interpretive Summary: The high neutral detergent fiber (NDF) in sorghum forage and silage causes low digestibility in cattle leading to limited intake. Sorghum with the brown midrib (bmr) trait, characterized by brown pigmentation of the leaf midrib, has increased digestibility, high forage quality, and promotes healthy rumens. Using the ARS sorghum mutant population, scientists at Lubbock, TX, Manhattan, KS, and Lincoln, NE, identified 3 new bmr mutants which could be used as alternative genetic stocks in breeding for highly digestible forage sorghum and silage. For public and private breeders, these new bmr lines are an additional source in breeding for bmr forage sorghum production.

Technical Abstract: Three new sorghum (Sorghum bicolor L.) bmr12 mutant germplasm lines—bmr12-30, bmr12-34 and bmr12-35 were developed for release by USDA–ARS Cropping Systems Research Laboratory in Lubbock, TX. The primary purpose for the release of these lines is to provide an alternative genetic stock of bmr12 mutants which could be used in forage breeding programs. The mutants were isolated from the pedigreed sorghum mutant library from an EMS-mutagenized sorghum inbred line BTx623. The derived mutations were confirmed by KASPAR markers designed to detect each mutation. The confirmed bmr mutants were physiologically and agronomically characterized under control and field conditions. All mutants showed the reddish-brown pigmentation in the leaf midrib, confirming the bmr phenotype. The bmr12 mutants flowered 4-5 days earlier than the wildtype BTX623. Seed physical and compositional characterization revealed no negative consequence of bmr on grain structure. However, bmr12 mutants had 14-24% more total protein than wildtype BTx623. For public and private breeders, these new bmr12 mutants are an additional source in breeding for bmr forage sorghum production.