PLANT-REGENERATION FROM STEM-DERIVED AND PETIOLE-DERIVED CALLUS OF HUMULUS-LUPULUS L (HOP) CLONE BAGANCA AND VAR BREWERS-GOLD

Plant regeneration was achieved from both a spontaneous clone (Braganc a) and Brewer's Gold variety of Humulus lupulus. The results obtained for these two different genotypes were compared. The organogenic abili ty of petiole and stem segments was tested on three different basal me dia supplemented with 0.025 mg (0.14 mu M) indole-3-acetic acid/L and 2 mg (8.87 mu M) 6-benzylaminopurine (N-6-benzyladenine)/L. These cond itions induced rather heterogeneous responses, which depended mainly o n the explant source and the genotype. Because of the high organogenic competence revealed by the spontaneous clone on modified Murashige an d Skoog medium, several hormones in different combinations were tested to optimize conditions for adventitious shoot regeneration in this cl one. The best relation between the average shoot number/callus and the regeneration rate was achieved with 0.025 mg (0.14 mu M) indole-3-ace tic acid/L and 2 mg (8.87 mu M) 6-benzylaminopurine/L or with 0.02 mg (0.11 mu M) indole-3-acetic acid/L and 1.5 mg (6.97 mu M) kinetin/L, w hich enabled 72 and 59% of regeneration, respectively. The regenerated plantlets could be acclimatized with 90% success.