PLANT TISSUE CULTURE In vitro propagation of Trichosanthes kirilowii Maxim. through nodal segment shoot proliferation Su Ji Joo 1 & A. Ra Yoon 1 & Yong-Goo Kim 1 & Byeong Cheol Moon 1 & Richard Komakech 1,2,3 & Youngmin Kang 1,2 Received: 13 December 2018 /Accepted: 11 July 2019 / Editor: Marie-Anne Lelu-Walter # The Society for In Vitro Biology 2019 Abstract Trichosanthes kirilowii Maxim. is a vital traditional herbal medicinal plant found in northeastern Asia. Its roots, fruits, and seeds are used as food and medicine. Roots harvested for medicinal use take over 3 yr to mature when the plant is grown in a traditional way through cultivation in the field. This coupled with uncertainty in identification of the plant when collected from the wild calls for a standard in vitro propagation system to meet the increasing demand for it. The purpose of this study was to develop a standard protocol for the in vitro micropropagation of T. kirilowii. Ten different media supplemented with different concentrations of plant growth regulators were evaluated. At 5 wk, De Greef and Jacobs medium supplemented with 0.1 mg L -1 kinetin led to optimal shoot growth, while the same medium supplemented with 0.5 mg L -1 indole 3-butyric acid induced optimal root growth, also at 5 wk. The micropropagated plants that were acclimatized for 8 wk in the greenhouse produced mature root tubers after planted in the field for 3 mo. Therefore, these findings provide a basis for future large-scale in vitro propagation of T. kirilowii. Keywords Biomass . In vitro propagation . Herbal medicine . Trichosanthes kirilowii . Radix Trichosanthis Trichosanthes kirilowii, called “Kwalu” in Korean, is an im- portant traditional herbal medicine in northeast Asia (Ryu et al. 1994). The seeds and root tubers of T. kirilowii are used in traditional Oriental medicine as a diuretic, and to treat se- vere coughing, inflammation, fever, jaundice, skin diseases, tuberculosis, breast cancer, and obstipation (Shin et al. 2008). Additionally, the plant is also widely known to treat other conditions including thoracic obstruction, pulmonary heart disease, angina, and cardiac failure (Yu et al. 2018). In fact, the dry roots of T. kirilowii are sold under the brand name of Radix Trichosanthis in traditional Chinese medicine (Chen et al. 2014). However, a large percentage of T. kirilowii is still collected from the wild to meet the increasing market demand, despite the fact that its accurate identification is very difficult due to the plant’ s changing and complicated morphology, which puts patients who rely on it in greater risk (Qian et al. 2012). Furthermore, the roots, which are the major medicinal part of the plant take over 3 yr to mature when the plant is grown using the traditional methods in the field (Kim et al. 2015 ). Normally, T. kirilowii has been naturally collected from wild culti- vation or seed propagation on Jeju island in South Korea, and the effects of climate change and maturation duration result in an urgent need to advance micropropagation methods to increase its domestic cultivation (Kim et al. 2015). Consequently, the present study aimed to establish a standard in vitro micropropagation protocol for T. kirilowii that can be used in the large-scale production of high-quality planting materials. Trichosanthes kirilowii plant materials (Fig. 1a–c) for this study was obtained from the Korea National Arboretum in Gyeonggi province, Korea. The nodal segments were washed with distilled water, surface sterilized with commercially pur- chased 70% (v/v) ethanol (Daihan Scientific, Siheung, Korea) for 1 min before thoroughly rinsing three times with autoclaved double distilled water in a laminar flow chamber. The shoots were further surface sterilized with 2% (v/v) S-J Joo, A-R Yoon, and Y-G Kim contributed equally to this work as first co-authors * Youngmin Kang ymkang@kiom.re.kr 1 Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, 111 Geonjae-ro, Naju-si, Jeollanam-do 58245, Republic of Korea 2 Korea Institute of Oriental Medicine (KIOM) Campus, Korean Convergence Medicine Major, University of Science & Technology (UST), Daejeon 34054, Republic of Korea 3 Natural Chemotherapeutics Research Institute (NCRI), Ministry of Health, P.O. Box 4864, Kampala, Uganda In Vitro Cellular & Developmental Biology - Plant https://doi.org/10.1007/s11627-019-10010-w