Registration of R16-45 as a flood-tolerant, high-yielding soybean germplasm line

Abstract

R16-45 (Reg. no. GP-526, PI 704118) is a high-yielding soybean [Glycine max (L.) Merr.] breeding line with flood tolerance at early reproductive stages released as germplasm by the Arkansas Agricultural Experiment Station in 2023. It is an F₂ selection from the cross between the flood-tolerant breeding line R07-6669 and the high-yielding Arkansas cultivar ‘UA 5612’. R16-45 is a conventional (non-genetically modified) soybean with a relative maturity of 5.6. Plants have determinate growth habit, white flower color, and buff hilum color. It has gray pubescence, tan pod wall at maturity, and yellow cotyledons with a dull yellow seed coat. R16-45 showed high yield potential and broad adaptability across 17 environments in Arkansas and other southern states, with an average of 4145 kg ha⁻¹ (95.3% of the checks’ mean). Six years of field evaluations for flooding tolerance showed that R16-45 is consistently tolerant to 8-to-10-day flooding stress at the R1/R2 growth stages (average flood damage score of 3.6, compared with 6.0 from the reference checks). In addition, R16-45 is resistant to stem canker. Given substantial yield losses associated with flooding stress and stem canker, R16-45 is a valuable germplasm source for public and private soybean breeding programs attempting to incorporate novel genetic diversity into their breeding pipeline.