The objective of this research was to assess the effects of different media i.e. Murashige and Skoog (MS) and Quoirin and Lepoivre (QL), cytokinin type i.e. 6-Benzyladenin (BA) and 6-Benzylaminopurine (BAP) and cytokinin concentration on in vitro proliferation of the G · N15 rootstock. To evaluate the effects of different media and cytokinin type, two separate experiments were conducted as factorial based on completely randomized design, and single nodes were used as explants. The results showed that MS nutrient medium was found to be superior to QL nutrient medium. Regarding the interaction between media and growth regulators, the best interaction was found in MS medium supplemented with 1 mg l À1 BAP resulting in 8.5 new micro shoots/explant while 7.75 shoots were observed in MS medium containing 1.25 mg l À1 BA. The longest length of new microshoots (2.10 cm) was obtained in hormone-free MS medium. Findings of this study showed that there is a significant correlation between the hormone level and plantlet height and formed callus weight so that an increase in BAP and BA levels in both of MS and QL media resulted significantly in height decrease and callus weight increase. The results also suggest that the best and the worst plantlets in terms of quality were observed in hormone-free QL medium and MS medium supplemented with 1.25 mg l À1 , respectively. These results reflect the fact that the presence of high amounts of NH 4 NO 3 and cytokinin especially BAP in culture medium triggered inhibitory effect on shoot growth. ª 2014 Production and hosting by Elsevier B.V. on behalf

Developing scale-up system and automation of micropropagation in a bioreactor has been a possible way of cost reduction and intensive manual handling. We report a comparison between the results of experiments aimed at improving carnation micropropagation using new bioreactor according to Temporary Immersion Bioreactor (TIB) and solid culture. By applying different levels of BAP, at the concentration of 3 mg L−1, we observed 14.3 new shoots in TIB, but the number of new shoots on solid medium reached to 5.7 at the same treatment. Our results also showed that with 3 mg L−1 BAP in TIB, the initial fresh weight of plant material increased from 10 g to 450 g after 15 days. It is concluded that TIB showed more than 10 times shoot production of carnation. Shoot elongation and rooting induction was successfully stimulated in TIB by applying 1 mg L−1 IBA. Rooting of proliferated plantlets from TIB and solid culture were successfully happened, and led to highest number of roots (4.6 cm) and highest length of roots (6.87 cm) in TIB. More than 90% of plantlet was acclimatized to ex vitro. Our results suggested that mass production of carnation shoots in our simple TIB, with effective result, can be considered as a critical first step toward large scale production of carnation.

Rose is known as the first and the most important cutflowers in all over the world. One of the common methods of mass production of this plant is propagation through tissue culture. The main limiting factor of rose tissue culture is Bacterial contaminations and phenolic exudation in the establishment phase that significantly makes most of explants spoiled. Nano-Silver is able to control and stop the bacterial contamination. In this experiment Nano-Silver was added to medium with concentrations of (, , and ppm) and in the other experiments explants were immersed in solutions of Nano-Silver with concentrations (, , and ppm) in complete random design. The experiments were carried out with four replications. The results showed that the concentration of ppm which is directly added to the medium can reduce Bacterial contamination and phenolic exudation rate. Concentration of ppm for minutes after surface sterilization was the best treatment of immersion to control bacterial contaminations. High concentrations of Nano-Silver make regeneration of explants more and more slower and in some cases lead to destroy explants. In general, Nano-Silver had no effects on fungal contamination.

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