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

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. R16-45 is a new conventional MG 5.6 determinate soybean germplasm.R16-45 has flood tolerance at R1/R2 growth stages.R16-45 has broad adaptation and high yield potential.