Perilla frutescens var. crispa has a unique aroma, purple leaves, and is similar in appearance to perilla. It is an annual herbaceous plant belonging to the Lamiaceae family, in addition it is known to have various pharmacological effects. In 1995, 200 Gy of gamma rays were irradiated to ‘Chookyoupjaso’ landrace seeds, and 6 candidate mutant lines with optimal agronomic traits were selected in the first round. Of them, one of mutant lines which had an increased isoegomaketone content and an anti-inflammatory component, were selected and cultivated. Subsequently, the variety protection right was registered in 2022 under the varietal name 'Antisperilll'. The main characteristics of 'Antisperilll' were that the leaf color changed from purple to green, the seed color from brown to gray, and the 1,000 seed weight was 3.29 g, which was approximately 1.7 times heavier than the original wild type (1.94 g). The isoegomaketone content, which exhibits anti-inflammatory effects, was increased and is expected to be used as a new health food and raw material to improve inflammatory diseases (Registration No. 8812).

Research on mutation breeding started in the early 1960s by researchers at the Atomic Energy Research Institute, Rural Development Administration (RDA) and several universities in Korea. The Radiation Agriculture Research Institute (RARI) was established in 1966, and studies of mutation breeding using radiation were actively conducted for a while. RARI was merged into the Korea Atomic Energy Research Institute (KAERI) and RDA in 1973, and radiation breeding research was neglected by the two agencies. In the 1980s, the relevant research department was lost, which resulted in a recession period of radiation breeding research. The Advanced Radiation Research Institute (ARTI), under the KAERI, was established to promote radiation research and the industry in 2005, which led to the activation of radiation breeding research. Then, the Radiation Breeding Research Center (RBRC) at the ARTI was established with support of the Ministry of Agriculture, Food and Rural Affairs in 2013. Recently, the importance of seed and genetic resources has been emphasized in Korea, and many institutes, companies and private breeders are interested in mutation breeding. The RBRC is trying to develop advanced radiation breeding techniques and new genetic resources using mutation techniques combined with bio-tech. This is to deal with the loss of biodiversity due to global climate change and environmental degradation, growing global demand for food and bio-energy, and to strengthen the protection for new plant varieties. Approximately 180 new mutant varieties were developed and registered officially in Korea. Recently, new mutant varieties, especially of flowers and ornamental plants, have quickly increased and are being commercialized, mainly by private company and breeders.

This study was carried out to compare the survival and mutation rates and mutation spectrum by gamma-irradiation on rooted and unrooted cuttings of three spray type (‘Lovelydia’, ‘Yellowbabe’, and ‘Haetsal’) and two standard type (‘Vital’ and ‘Aqua’) cultivars in roses. Two groups, rooted and unrooted cuttings were gamma-irradiated at 70Gy for 24 hours. The irradiated rooted and unrooted cuttings were planted in a greenhouse, and survival, mutation rates and mutation spectrum were investigated 30 weeks after planting, respectively. As a result, survival and mutation rates of gamma-ray irradiated plants were 16.4%~50.8% and 0~5.1% for unrooted cuttings, and 39.4%~55.1% and 0.7%~7.4% for rooted cuttings, respectively. In conclusion, both survival and mutation rates were a little higher on rooted cuttings than on unrooted cuttings. However, when only survived plants after gamma-ray irradiation were considered, mutation rates were 0~10% and 1.8%~14.1% for unrooted cuttings and rooted cuttings, respectively, showing no significant difference. In addition, diverse variations on color and number of petals or shape of flowers were detected both in plants from rooted and unrooted cuttings, which indicated that there was no significant difference in mutation spectrum between two groups.

Kenaf (Hibiscus cannabinus L.) is an annual herbaceous crop of the Malvaceae family. Recently, kenaf is being used in many diversified applications such as pulp, animal feed, bioplastics and cellulosic biofuel etc. A new cultivar 'Jangdae' was developed by mutation breeding using irradiated with 300 Gy gamma-rays. Jangdae has a few distinguishable characteristics such as early flowering, high seed yield and palmate leaf, compared to wild type (Jinju). The fresh matter (FM) and dry matter (DM) yield of Jangdae are similar to those of Jinju, their seed yield (833.3 kg/ha) is approximately 4 times higher than that of Jinju. In addition, the FM and DM yield of Jangdae are 40% higher than those of early-maturing cultivar (C11). We performed the nutritive value of four kenaf cultivars (Jangdae, Jinju, C11 and Hongma300) at 100 day after seeding. The crude protein content of Jangdae, Jinju, C11 and Honma300 were 10.5, 11.0, 9.4 and 10.6%, respectively. The crude fiber, neutral detergent fiber and acid detergent fiber contents were no significant difference among the cultivars. Jangdae, which afforded both a high biomass and seed yield in South Korea, may be useful as potential source of feed and industrial materials.

A new soybean cultivar ‘Wonhyun’, was developed by mutation breeding technique using a 250 Gy gamma ray at Korea Atomic Energy Research Institute (KAERI) in 2010. ‘Wonhyun’ has black seed coat and much better agronomic performance than original variety ‘Paldal’. Their total yield (177.1kg/10a) is much higher than that of ‘Paldal’ (126.9 kg/10a). Also, 100 seed weight of Wonhyun was 27g compared to ‘Paldal’ (13.7g). Contents of 4 essential amino acids such as aspartic acid, glutamic acid, lysine, arginine and unsaturated fatty acid including linoleic and linolenic acid have much higher than ‘Paldal’. This cultivar is good for cooking with rice as improved functional ingredient soybean.