The present experiments were conducted at Humboldt University of Berlin, Horticultural Plant Systems, Germany during 2012 and 2013 seasons, to clarify the nutrient requirements for regeneration of encapsulated nodal segments of Rosa hybrida `Kardinal´ , as well as define the nutrient losses from the beads during incubation on nutrient-free media. Shoot cultures were cultivated on modified MS medium. For encapsulation, 4 to 5 mm nodal segments were isolated 3 weeks after subculturing. The nodal segments were put in 3% Na-alginate diluted in the modified MS medium with various sucrose concentrations (30 to 90 g l-1) and 0.5 to 2 mg l-1 indole-3-butyric acid (IBA). To improve the nutrient supply, 85 µl, 95 µl or 105 µl of Na-alginate with one nodal segment was dropped in to 75 mM CaCl2 dissolved in the same media contains Na-alginate for 30 min hardening. The results showed that already after 24h incubation on the water-agar-medium more than 90% of nitrate was diffused out of the beads. The reduction of water-agar-medium volume from 25 ml to 7 ml reduced the nutrient leakage and improved the shoot formation from 40 to 90%. The root regeneration of the encapsulated nodal segments also increased from 40% to 80% either by increasing the bead volume from 85 to 105 µl or the sucrose concentration from 30 to 50 g l-1 in the propagation medium. The highest conversion (approximately 50%) was found after supplying 1 mg l-1 IBA and 90 g l-1 sucrose to the bead gel matrix.

Divers studies have demonstrated that plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) can stimulate plant growth and more recently that they can increase rooting ability in vegetative material, especially when they are added with auxin. Considering this potential, the objective of this study was to verify the effect of PGPR and AMF in combination with IBA on rooting and growth of some types of bougainvilleas cutting. Three cutting types (tip, middle and basal) were prepared from four bougainvilleas, namely B. glabra var. sanderiana, B. glabra var. variegata, B. spectabilis "Snow White" and B. spectabilis "Yellow Hybrid" in both 2012 and 2013 years. The cuttings were taken from Bougainvillea mother plants in March and treated with three PGPR (Azospirillum brasilense, Pseudomonas fluorescens and Bacillus subtilis) and AMF (Glomus intraradices) in combination with 100 ppm IBA. The all combined treatments of IBA plus PGPR or AMF showed higher rooting percentages than hormone treatment (IBA alone). Among bougainvilleas used, average the highest rooting were observed in B. spectabilis "Snow White" (62.0%), followed by B. glabra var. sanderiana (61.2%), B. spectabilis "Yellow Hybrid" (60.5%) and B. glabra var. variegata (54.7%), respectively. The highest rooting percentages were obtained from basal cuttings treated with 100 ppm IBA plus either G. intraradices, A. brasilense or B. subtilis in all bougainvilleas. Overall, the lowest was observed in the IBA treatment alone. C/N ratio and endogenous root-promoting substances in cutting base were parallel with the rooting ability. The present investigation clearly showed that the combination of PGPR or AMF inoculums and rooting hormone can increase root initiation and potentially increase the quality of rooted cutting produced. Furthermore, the success of root promotion depends on the used strain and genotypic response of Bougainvillea species.

Divers studies have demonstrated that plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) can stimulate plant growth and more recently that they can increase rooting ability in vegetative material, especially when they are added with auxin. Considering this potential, the objective of this study was to verify the effect of PGPR and AMF in combination with IBA on rooting and growth of some types of bougainvilleas cutting. Three cutting types (tip, middle and basal) were prepared from four bougainvilleas, namely B. glabra var. sanderiana, B. glabra var. variegata, B. spectabilis "Snow White" and B. spectabilis "Yellow Hybrid" in both 2012 and 2013 years. The cuttings were taken from Bougainvillea mother plants in March and treated with three PGPR (Azospirillum brasilense, Pseudomonas fluorescens and Bacillus subtilis) and AMF (Glomus intraradices) in combination with 100 ppm IBA. The all combined treatments of IBA plus PGPR or AMF showed higher rooting percentages than hormone treatment (IBA alone). Among bougainvilleas used, average the highest rooting were observed in B. spectabilis "Snow White" (62.0%), followed by B. glabra var. sanderiana (61.2%), B. spectabilis "Yellow Hybrid" (60.5%) and B. glabra var. variegata (54.7%), respectively. The highest rooting percentages were obtained from basal cuttings treated with 100 ppm IBA plus either G. intraradices, A. brasilense or B. subtilis in all bougainvilleas. Overall, the lowest was observed in the IBA treatment alone. C/N ratio and endogenous root-promoting substances in cutting base were parallel with the rooting ability. The present investigation clearly showed that the combination of PGPR or AMF inoculums and rooting hormone can increase root initiation and potentially increase the quality of rooted cutting produced. Furthermore, the success of root promotion depends on the used strain and genotypic response of Bougainvillea species.

This study was conducted at the Horticulture Farm, Faculty of Veterinary and Agricultural Science, El-Zawia University, Libya during 2014 and 2015 seasons, to investigate the effect of indole-3-butyric acid (IBA) concentrations (0, 50 and 100 ppm) alone or in combination with Bacillus subtilis on the rootability, root and shoot growth of Rosmarinus officinalis L. cuttings under salt stress conditions (control, 1000, 2000 and 4000 ppm NaCl). The obtained data revealed that irrigation of cuttings with NaCl at 2000 and 4000 ppm resulted in a significant reduction in rooting percentage, root and vegetative growth characteristics, contents of N, P and K as well as C/N ratio in cutting tissues compared to control and the lowest salinity level used, whereas Na % and Na/K ratio were high, especially at high salinity levels. Treatment of cuttings with IBA alone or combined with B. subtilis modified and alleviated most of the harmful effects of salt stress, especially at the lower salinity level. Generally, the combination of IBA at 50 ppm with B. subtilis had a profound effect in increasing rootability, root and vegetative growth characteristics of plants compared to the control and all other treatments. The same treatment increased contents of N, P and K as well as C/N ratio, whereas reduced Na % and Na/K ratio in the rooted cutting tissues. So, it could be recommended to use this treatment for alleviation of adverse effects of irrigation water salinity on rooting and growth of R. officinalis cuttings.

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