An investigation on the effect of different plant growth regulating compounds in in vitro shoot tip and node culture of lemon seedlings

The possible application of some less commonly used in vitro growth regulat ing compounds is outlined. A number of treatments were applied to determine the best way of inducing in vitro shoot proliferation and rooting on a mod ified Driver-Kuniyuki [HortScience 19 (1984) 507] basal medium of lemon (Ci trus limon (L.) Burm, f. cv. Interdonato) seedlings. 6-Benzyladenine (BA) a lone (1, 2 and 4 mg l(-1)) and in combination with either orange juice (10% , v/v), silver nitrate (3 mg l(-1)), gibberellic acid (GA(3)) (0.1 mg l(-1) at the establishment stage and 0.5 mg l(-1) at all combinations during the proliferation stage) or abscisic acid (ARA) (0.2 mg l(-1) only at the esta blishment stage) were used to stimulate shoot formation during the establis hment and the proliferation stage. The combination of BA with ABA gave a hi gh rate of shoot formation, while GA(3) and silver nitrate enhanced shoot e longation. When these shoots were transferred to the rooting stage, the eff ect of application of two different auxins (indole-3-butyric acid (IBA) and alpha -napthaleneacetic acid) was examined, as well as different methods o f application (auxin added to the basal medium and auxin application by dip ping the base of the explant in auxin solution). Dipping the base of the ex plants in a 50% ethanol solution of IBA at 1000 mg l(-1) for 5 s resulted i n 80% rooting with subsequent 90% survival of these explants, during acclim atization under mist. (C) 2001 Elsevier Science B.V. All rights reserved.