The effect of silicon on the qualitative and biochemical characteristics of cut roses under water stress conditions

Silicon is one of the beneficial elements in the growth of plants, and its positive effects on resistance to abiotic stresses, including salinity and drought, have been proven in some studies. The present study aimed to evaluate the effects of silicon and water stress on the qualitative and biochemical traits of the cut rose, Club Nika cultivar, with three concentrations of potassium silicate (0, 0.5, and 1 mM) and three levels of water stress (100 (control), 75, and 50% of plant water requirement) as a factorial experiment, in a randomized complete block design with four replications, under greenhouse conditions. In this study, qualitative indicators such as the number of superior branches, branch diameter, and flower diameter, as well as biochemical parameters such as chlorophyll and proline content of leaves, were measured. The results showed that plants grown in the 100% irrigation treatment had higher branch diameter, number of superior branches, fresh and dry weight of flowering branches, flower diameter, leaf area, and relative water content than plants under water stress conditions. The time required for germination of buds in the 100% water requirement treatment was faster (about 6.83 days) compared to plants under stress conditions. This is while water stress treatments (50 and 75% of water requirement) did not show significant effect on total number of harvested shoots, chlorophyll content and proline content of leaves. In this study, although the application of potassium silicate at a concentration of 1 mM was able to improve most of the quality traits of cut-off rose, this difference was not statistically significant. It seems that the lack of significance of silicon treatments is related to the distribution of silicon in leaves and the ineffectiveness of these treatments on cuticular transpiration and stomatal conductance. Overall, the results indicate that the adaptation process of cut-off roses to water stress occurs through morphological mechanisms and osmotic processes such as the synthesis of the amino acid proline and the utilization of silicon are not involved.