Before revision: 37(2): 250-254 the use of cytokinin-meta-topolin (6-(3-Hydroxybenzylamino)purine), combination of lower cytokinin content and ammonium nitrate in the media , use of nitrate or glutamine as the sole nitrogen source and decreasing the ratio of NH4+: NO3 − in the medium.Bairu M, Stirk W, Dolezal K, Van Staden J (2007).
After revision: 37(2): 250-254 the use of cytokinin-meta-topolin (6-(3-Hydroxybenzylamino)purine), combination of lower cytokinin content and ammonium nitrate in the medium , use of nitrate or glutamine as the sole nitrogen source and decreasing the ratio of NH4+: NO3-the in the medium.Bairu M, Stirk W, Dolezal K, Van Staden J (2007).