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The aim of the present investigation was to optimize protocols for micropropagation and adventitious shoot regeneration from leaf explants of two wild ecotypes of red flesh apple Malus niedzwetzkyana for future breeding programs. At the proliferation stage, different concentrations of sodium nitroprusside (SNP) and triacontanol (TRIA) were compared. To optimize shoot regeneration from leaf explants, interactive effects of 1-phenyl-3-(1,2,3-thidiazol-5-yl)-urea – thidiazuron (TDZ), indole-3-butyric acid (IBA) and two explant types were investigated. At rooting stage, the effect of exposure time of microshoots to darkness and exposure time to different concentrations of IBA and α-naphthalene acetic acid (NAA) were compared. The results showed that SNP affected the growth rate significantly and the maximum multiplication rates per explant (9.6 in the first ecotype and 8.8 in the second) were produced in the Quoirin and Lepoivre medium containing 17 SNP µM, in addition to 4 µm 6-benzylaminopurine (BAP) and 3 µm gibberellic acid (GA3). IBA and TDZ affected the adventitious shoot regeneration from leaf explants significantly, the highest number of regenerated shoots (18.3 per explant) was obtained from the basal section of the leaves cultured on the medium containing 2 μM IBA and 15 μM TDZ. At rooting stage, the maximum rooting (88.6%) was obtained in the result of one weak exposure to darkness on medium containing 3 μM IBA.

In vitro propagation of plant has played a very important role in rapid multiplication of cultivars with desirable traits and production of healthy and disease-free plants. In the present investigation, the objectives were to optimize the micropropagation of Rose hybrid 'Black Baccarat' cultivar. In proliferation step, the nodal segments (1.5 cm) was cultured on both liquid and solid media (MS, VS and WPM). The results showed that the highest shoot proliferation was obtained on VS medium. The highest amount of multiplication and the growth rate were obtained in the liquid medium. For rooting, three concentrations of VS mineral salts (full-, half-, and quarter-strength) containing NAA (0.5 μM) were tested in semi-solid and liquid media. Root initiation influenced by mineral concentration in the medium. The investigation showed that the highest number of roots was observed in semi-solid 1/4 VS medium. Variation in multiplication and growth rate of explants can be explained on the basis of water potential and mineral availability to the explants in the liquid medium. [ABSTRACT FROM AUTHOR]