Production of cucumber fruits from the culture of ‘Marketmore-76’ plantlets
A procedure to produce fruits from cultured shoot tips of Cucumis sativus L. cultivar ‘Marketmore-76’ in vitro is described. Four-week-old shoot tips, derived from sterile germinated seedlings on a MS medium, were cultured in a 3.8-1 Mason jar using an automated plant culture system. Tips readily generated roots, leaves and flowers after another 4 to 8 weeks in culture. Administration of compressed air at a 300 ml/min flow rate for 30 min 10 or 15 times a day induced the development of parthenocarpic fruits from flowers. Fruits, up to 170 mm long by 35 mm diameter, were obtained within 30 to 45 d after flower opening.
Improved Flowering of Cotyledon- derived Shoots of 'Burpless Hybrid' Cucumber in Vitro
Table 1. The effect of BA and NAA on the development of adventitious shoots and flowers from cotyledons of ‘Burpless Hybrid’ cucumber in vitro.z The ability of cucumber (Cucumis sativus L.) cotyledons to develop flowers in vitro was reported by Msikita et al. (1990). The majority of those flowers in culture were staminate (up to 48%); a few pistillate flowers (up to 12%) were obtained through media manipulation. In this paper, we report further investigations concerning the control of sex expression among adventitious cotyledon-derived cucumber flowers. Cotyledon explants (without embryonic axes) of ‘Burpless Hybrid’ cucumber were prepared and disinfested as described by Msikita et al. (1990). Explants were transferred to modified Murashige and Skoog (MS) medium (Murashige and Skoog, 1962) supplemented with 20 combinations of 6-benzylaminopurine (BA; 0.1, 0.2, 0.3, or 0.5 mg·liter-l) and naphthaleneacetic acid (NAA; 1.0, 2.0, 3.0, 4.0, or 5.0 mg·liter-1) (Table 1). Staba (1969) vitamins were added before autoclaving (at 106 kPa and 120C for 15 min). The pH was adjusted to 5.7, and agar (7 g·liter-1) was added. Cultures were grown for 2 months at 25C under coolwhite fluorescent tubes (40 μmol·m -2·s-1) with a 16-h photoperiod. The experiment consisted of 24 single-explant replicates per treatment arranged in a 5 × 4 factorial. Data were analyzed using the General Linear Model procedure of SAS Inst., Cary, N.C. Shoots regenerated on all media supplemented with NAA at 3 3.0 mg·liter-1 (Table l), but none regenerated at lower concentrations of NAA (data not presented). Adventitious flower development (Fig. 1) was observed only on media supplemented with NAA at 3.0 mg·liter-1 and the three highest
Heavy metal adsorption from industrial wastewater by PAMAM/TiO2 nanohybrid: Preparation, characterization and adsorption studies
Abstract This study investigates the removal of heavy metals from industrial wastewater using TiO 2 nanoparticles modified with poly-amidoamine dendrimer (PAMAM, G 4 ). The metal ions Cu 2 + , Pb 2 + , and Cd 2 + were selected as model pollutants. FTIR, SEM, BET surface area and Zeta potential measurements, and Dispersion Observing methods have been employed for characterizing the synthetic nanohybrid and these techniques indicated that the PAMAM loaded on to TiO 2 have been favorably synthesized. The effects of several parameters including initial metal ion concentration, temperature, pH solution, the nanohybrid dosage and contact time were studied. The experimental data were analyzed using equilibrium isotherm and kinetics models. The adsorption process was studied using isotherm, kinetics, and thermodynamics models. The analysis shows that the Langmuir isotherm and pseudo-second-order kinetics are appropriate models for the adsorption process. The thermodynamic parameters illustrate that the absorption is endothermic and spontaneous. The findings suggest that the nanohybrid is a good super absorbent for the removal of heavy metals from industrial effluents.