Abstract:
This study was carried out during the period of 10/2015-2/2016 at the Tissue Culture Laboratory complex, Department of Horticulture, College of Agricultural Studies, Sudan University of Science and Technology, Shambat, with the objective of determining salinity tolerance of garden rocket (Eruca sativa Mill.). The effect of different concentrations of sodium chloride (NaCl) on germination of seeds and vegetative and reproductive growth of garden rocket plants was evaluated. The treatments were NaCl concentrations: 0.00, 0.02, 0.03, 0.10 and 0.13 molar (M). The final germination percentage, the germination rate index (GRI) and the corrected germination rate index (CGRI) were not affected by the salt concentrations tested. The final germination percentages were very high (above 85%), likewise the seed germination rate, evaluated by GRI and CGRI, was very high. The elongation of the radicle as well as the plumule was negatively affected by increasing salt concentrations. Leaves formation was not affected by all salt concentrations tested but leaves length was reduced with increasing salt concentrations. The results also indicated that the elongation of the stem was less affected by the two lowest salt concentrations (0.02, 0.03 M), but was drastically reduced by the two highest salt concentrations (0.10M and 0.13M). Flower formation was detrimentally affected by increasing NaCl concentration. The highest concentration inhibited flower formation completely. The number of fruits per plant followed almost the same trend, with the two highest concentrations inhibited fruit set completely. It is apparent from this study that both flower number and fruit set are the most sensitive parameters to salt stress. In general, the highest two concentrations of the salt tested, (0.10M and 0.13M), were inhibitory to all growth parameters measured. It is not apparent from this study whether the detrimental effects were due to osmotic or toxicity effects or due to both.
