ADVENTITIOUS BUD REGENERATION FROM LEAF EXPLANTS OF THE SHRUBBY ORNAMENTAL HONEYSUCKLE, LONICERA-NITIDA WILS CV MAIGRUN - EFFECTS OF THIDIAZURON AND 2,3,5-TRIIODOBENZOIC ACID

Different combinations of auxins and cytokinins were employed to assess the regeneration capacity from in vitro leaf explants of Lonicera nitida Wils. cv 'Maigrun'. A high frequency of rhizogenesis was noticed, with 2.3-mu-M thidiazuron plus 2.9-mu-M indole-3-acetic acid as the only hormonal combination to support caulogenic responses. Increasing thidiazuron concentration and/or suppressing auxin did not improve caulogenesis. Combining thidiazuron with 2,3,5-triiodobenzoic acid produced a dramatic increase in the percentage of caulogenic explants. A maximum of 74% of adventitious bud forming explants was obtained with 2.3-mu-M thidiazuron plus 20-mu-M 2,3,5-triiodobenzoic acid. Buds were often in a rosette form and were vitreous, so that shoot elongation was difficult to obtain. The effect of the duration of the 2,3,5-triiodobenzoic acid treatment on shoot elongation was investigated.