Ethylene inhibitors and low kanamycin concentrations improve adventitious regeneration from apricot leaves

An improved method for adventitious regeneration from apricot leaves is described. The use of the ethylene inhibitors silver thiosulphate (30-60 muM) or aminoethoxyvinylglycine (0.5 muM) increased regeneration percentages in Helena and Canino apricot cultivars and also the consistency of results from different experiments. Use of 'Pure Agar' also improved regeneration from Helena leaves as compared with agargel or agarose. Regeneration rates for Canino were dependent on the medium in which the shoots were micropropagated. When different antibiotics were tested for their influence on regeneration, the combination of cefotaxime (0.13 mM) plus vancomycin (0.63 mM), which efficiently controls Agrobacterium growth, also increased regeneration percentages in Helena two-fold but did not affect regeneration in Canino. Kanamycin, an antibiotic widely used for selection of nptII transformed cells, promoted more rapid regeneration and higher regeneration rates from Helena leaves when added at low concentrations (8.6 and 17.1 muM). With this improved procedure, regeneration from apricot leaves has been increased more than 200% as compared with rates reported previously.