Perilla is a traditional oilseed crop cultivated in Korea. The ‘Nulsaemi’ cultivar was developed for oil use because of its large seed size and high functional compound content. It originated from a cross between ‘Daesil’ (IT274265), with high crude fat content and a soft seed coat, and ‘Milyang16’ (K015415), with large, brown seeds and a hard seed coat. The cross was created in 2008, and promising lines were selected through pedigree breeding up to the F₆ generation. Advanced yield trials were conducted in 2016 and regional yield trials were conducted at four sites (Milyang, Suwon, Cheongju, and Iksan) from 2017 to 2019. ‘Nulsaemi’ matures around October 8, which is slightly later than the standard cultivar ‘Dayu’. It also has a 1,000-seed weight of 5.2 g, which is 1.4 g heavier than ‘Dayu’. The seed hardness was low, making it suitable for processing. The average yield was 125 kg/10a, about 3% higher than that of ‘Dayu’. The seeds contained approximately 45.1% crude fat and 63.4% alpha-linolenic acid, similar to those of the standard cultivar. However, rosmarinic acid content was significantly higher at 2,130.6 μg/g, about 18% more than ‘Dayu’. In sensory evaluation, oil extracted from ‘Nulsaemi’ showed better appearance, aroma, taste, and overall preference compared to the control, in both cold-pressed and roasted oil types. ‘Nulsaemi’ is expected to be a high-quality oilseed cultivar suitable for premium perilla oil production (Registration No. 8792).

‘Saebom’ is a new vegetable perilla (Perilla frutescens (L.) Britton) variety developed at the National Institute of Crop Science, Rural Development Administration, in 2020, following a cross made in 2011 between YPL54-2B-36-1-1-1-2-2 and YPL83-2B-5-2-5. It was developed using a pedigree breeding method. YPL156-2B-9-2-1-3-2 was selected and named ‘Milyang 83.’ Subsequently, summer and winter productivity tests were conducted. ‘Saebom’ has small, round-shaped leaves and its maximum leaf length is 13.1 cm, which allows for the distribution of leaf harvesting labor. In addition, the leaves are thick, which is beneficial for storage, and the ratio of the apical leaf length/leaf length is 55.8% (‘Namcheon’ 37.2%). This value is considered high and makes ‘Saebom’ highly marketable. Its leaf yield and leaf number were 10% and 8% higher than those of ‘Namcheon,’ respectively, and its antioxidant activity was also higher. In December 2020, the variety was named ‘Saebom’ by the new variety selection committee for its excellence, and its variety protection rights were registered in 2023 (Registration No. 9305).

This study used perilla seeds produced in 2019, 2020, and 2021 to determine the year of production using multivariate statistical analysis of Fourier-transform infrared (FTIR) spectral data of perilla leaves. Spectral analysis based on multivariate statistical analysis of whole-cell extracts was used to distinguish the perilla leaves at the metabolic level. FT-IR spectral data of the leaves were analyzed using principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The FTIR spectrum identified spectral differences between the frequency regions of 1,700 to 1,500, 1,500 to 1,300, and 1,100 to 950 cm^-1. This spectral region reflects quantitative and qualitative changes in amides I, II in amino acids and proteins (1,700–1,500 cm^-1), phosphodiester groups from nucleic acids and phospholipids (1,500–1,300 cm^-1), and carbohydrate compounds (1,100–950 cm^-1). PCA revealed separate clusters corresponding to production traceability relationships. Therefore, PCA can be used to distinguish between production in 2019, 2020, and 2021 based on different metabolite contents. PLS-DA showed a similar production traceability classification for the perilla seeds. In addition, this metabolic identification system can be used to rapidly select and classify useful perilla seed varieties.

Perilla has a long history of cultivation and consumption in Korea. Its cultivar ‘Sodam’, which is used for its oil and powder, was developed from a cross between two parents ‘K015926’ and ‘Miryang27’. The parents were crossed in 2004, and their progenies were selected from F₃ to F₅ generations through pedigree method. Regional yield trials (RYTs) were conducted in four regions from 2012 to 2014. ‘Sodam’ is a light gray and small spherical-seeded cultivar. It matures earlier (October 2) than ‘Saeyeopsildeulkkae’, a standard cultivar, and the number of flower clusters per plant as well as the number of ears per cluster is higher in ‘Sodam’ than in the standard cultivar. Its seeds contain approximately 46.4% crude fat, and the oil is rich (about 65.0%) in alpha-linolenic acid, an omega-3 fatty acid. ‘Sodam’ is characterized by upright plant growth with narrow branch angles. The average yield of this cultivar was 1.23 ton/ha in adaptable regions. ‘Sodam’ is expected to be a potential cultivar source for production of good quality perilla oil (Registration No. 6729).

Perilla is an oilseed crop cultivated in Korea since ancient times. Due to the high α-linolenic acid content in perilla, perilla seed oil can easily become rancid. α-Linolenic acid is synthesized by two enzymes, endoplasmic reticulum-localized Δ15 desaturase (FAD3) and chloroplast-localized Δ15 desaturase (FAD7) in vivo. In order to lower the α-linolenic acid content of the seed oil without disturbing plant growth, we tried to suppress the expression of only the FAD3 gene using RNA interference, whilst maintaining the expression of the FAD7 gene. Seventeen transgenic plants with herbicide (Basta™) resistance were obtained by Agrobacterium-mediated transformation using hypocotyls of perilla plants. The transgenic plants were firstly confirmed by treatment with 0.3% (v/v) Basta™ herbicide, and the expression of FAD3 was measured by Northern blot analysis. The α-linolenic acid content was 10-20%, 30-40%, and 60% in two, seven, and three of the twelve T₁ transgenic perilla plants which had enough seeds to be analyzed for fatty acid composition, respectively. Analysis of the fatty acid composition of T₂ progeny seeds from T₁ plants with the lowest α-linolenic acid content showed that the homozygous lines had 6-10% α-linolenic acid content and the heterozygous lines had 20-26% α-linolenic acid content. It is expected that the reduction in α-linolenic acid content in perilla seed oil will prevent rancidity and can be utilized for the production of high-value functional ingredients such as high γ-linolenic acid.

Perilla cultivar ‘Deulsaem’ was developed for perilla oil and powder. ‘YPL139’ and ‘Daesildeulkkae’ crossed in 2003 and selected from F₃ to F₅ by pedigree method. The selected pedigree is ‘YPS142-B-28-1-3-2-2’ and named as Miryang No. 57. The regional yield trial (RYT) in five regions was conducted from 2011 to 2013. In RYT, ‘Deulsaem’ was a high yield and quality. ‘Deulsaem’ is determinate, white flower and brown spherical seed. Maturity date was Oct. 8, similar to ‘Saeyeopsildeulkkae’(standard cultivar). However, ‘Deulsaem’ has higher number of flower cluster and ear per cluster than ‘Saeyeopsildeulkkae’. The yield of oil content and linolenic acid of ‘Deulsaem’ was 39.4% and 61.0%, respectively. The yield in adaptable regions was 1.42 ton/ha (5% increase compared to ‘Saeyeopsildeulkkae’) and ‘Deulsaem’ is expected to be cultivated and used widely for good quality perilla oil. (Registration No. 6246)

An interspecific cross between P. citriodora and P. hirtella constitutes ideal material for a linkage map construction in genome project of Perilla. The chromosomes of the species are same with n=10 and progenies of the cross are normal in growth and seed set. The phenotype of F2 population of the cross are normally distributed and this is a proof of high affinity of the chromosomes during their sexual reproduction. Rosmarinic acid, Luteolin and Apigenin contents of F2 plants were distributed in similar range with tetraploid perilla cultivars. Luteolin and Apigenin are positively correlated with correlation coefficient of 0.762. 21 QTLs were detected in agronomic traits and Rosmarinic acid, Luteolin and Apigenin contents. Even though Luteolin and Apigenin are positively correlated, QTLs were located in different position. Purple leaf color related QTL was mapped in Chromosome 3 with LOD of 14.3, PVE of 50.4%. Three anthocyanin biosynthesis transcription factor like sequences, WD40 repeat-like superfamily protein, myb domain protein 43 and basic helix-loop-helix (bHLH) DNA-binding superfamily protein, were detected near from the QTL.