eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-03-31 13 1 53 58 10.13005/bbra/2002 7459 article Jae Kwang Kim 1 Thanislas Bastin Baskar 2 Sang Un Park 2 Division of Life Sciencesand Bio-Resource and Environmental Center, Incheon National University, Incheon 406-772, Korea. Department of Crop Science, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon, 305-764, Korea. Polygonumtinctorium, also known as indigo plant, is widely distributed in Japan. Only few studies have investigated the regeneration of the indigo plant. The aim of this study was to develop an efficient protocol for shoot regeneration and shoot elongation. Shoot organogenesis and plant regeneration from internode explants of P. tinctorium were improved using the ethylene inhibitor silver nitrate (AgNO₃)and thepolyamine putrescine. Culturing of internode explants on initial shoot regeneration media (Murashige and Skoog media with 6-benzylaminopurineat 2 mg/L) supplemented with different concentrations (0, 1, 5, 7, 10, 20mg L^-1) of AgNO₃ significantly improved the regeneration efficiency, resulting in higher numberof shoots per explant and longer shoot length. The greatest number of shoots (7.2 ± 0.8) and shoot length (2.1 ± 0.1 cm) were obtained in media supplemented with 7 mg L^-1AgNO₃, and further increase in the concentration of AgNO₃ decreased the shoot production and shoot length. Additionally, we evaluated the effect of various concentrations (0, 10. 30, 50, 100, 200 mg L^-1) of putrescine on shoot regeneration and shoot length. The highest number of shoots (7.4 ± 0.8) and longest shoots (2.2 ± 0.1 cm) were observed in cultures supplemented with 50 mg L^-1putrescine and further increase in concentration reduced the shoot regeneration and elongation. Our present study suggested that the addition of ethylene inhibitor AgNO₃ and polyamine putrescine could be applied in micropropagation and plant transformation protocols of P. tinctorium. https://www.biotech-asia.org/vol13no1/silver-nitrate-and-putrescine-enhance-invitro-shoot-organogenesis-in-polygonumtinctorium/ Polygonumtinctorium; Plant regeneration; Silver nitrate; Putrescine