Rapeseed (Brassica napus L.) is typically grown under field conditions in Korea, with one generation per year, and requires 6-7 years to develop homozygous lines. This study established generation-acceleration protocols for different rapeseed growth types by combining speed breeding (SB) and speed vernalization (SV) and evaluated their applicability to Korean-bred cultivars and lines. Under SB (22 h light/2 h dark), the spring and semi-winter types flowered at 33 and 43 days after sowing, respectively, whereas bolting was not observed in the winter-type. In contrast, the winter-type flowered after SV at 10℃ for 2 weeks under an extended photoperiod (22 h light/2 h dark), followed by transfer to SB conditions (SV(2)-SB). For all three types, pods were harvested 45 days after flowering, and seed germination exceeded 95%. Accordingly, the spring and semi-winter types achieved four generations per year under SB, whereas the winter type achieved three generations per year under SV(2). When applied to Korean-bred cultivars and lines, SB induced flowering in all accessions and most seeds germinated (>90%), enabling four generations per year. However, no seed set was obtained in one cultivar (‘Yuryeo’), indicating that further optimization is needed to ensure reliable seed production under generationacceleration conditions. Overall, these protocols account for growth-type-dependent vernalization requirements and provide a foundation for shortening the rapeseed breeding cycle, with the flowering response and white-flower phenotype as practical selection indicators.
Eunyoung Oh, Gyeong-Dan Yu, Da-Hee An, Jaehee Jeong, Hyun-Min Jo, Young-Lok Cha, Sungup Kim, Jung In Kim, Min Young Kim, Sang Woo Kim, Jeongeun Lee, Eunsoo Lee, Myoung-Hee Lee
Korean. J. Breed. Sci. 2025;57(4):465-473. Published online December 1, 2025
‘K-Ol2’ is a high-oil, high-oleic acid peanut (Arachis hypogaea L.) variety developed by the National Institute of Crop and Food Science and released in 2022. This variety was derived through pedigree selection from a single cross between the variety ‘Jaseon’ and the high-oleate elite line ‘YG377’. High-oleate lines were selected in the F3 generation using Near-Infrared Spectrophotometry and gas chromatography. ‘K-Ol2’ exhibits a relatively short plant height with main stem and branch lengths of 29 cm and 36 cm, respectively, which are less than those of the check variety ‘Akwang’. The seeds had a brown testa and an elliptical kernel shape, with a 100-seed weight of 87 g and an average of 54 mature pods per plant. Seed composition analysis revealed an average protein content of 29.3% and a high crude fat content of 54.5%. The oleic acid (C18:1) content reached 82.8%, with an oleic to linoleic acid ratio of 28.5:1, significantly higher than that of ‘Akwang’ (2.2:1). In oxidative stability evaluations under accelerated oxidizing conditions, ‘K-Ol2’ exhibited an extended induction time to reach maximum conductivity increase, indicating improved resistance to lipid oxidation. Regional yield trials conducted from 2020 to 2022 demonstrated that ‘K-Ol2’ produced an average yield of 4.60 MT⋅ha-1, representing a 10% increase over ‘Akwang’. Due to its high oil content and improved oxidative stability, ‘K-Ol2’ is expected to play a valuable role in the peanut processing industry (Registration No. 10358).