Effect of a sodium carboxymethyl cellulose composite hydrogel on tobacco growth and development under drought stress

In order to promote the growth and development of tobacco and reduce the adverse effects of drought on tobacco, acrylamide/sodium carboxymethyl cellulose/modified biochar hydrogel (AM/CMC/MB) was prepared by crosslinking polymerization reaction. The structural characteristics of the hydrogel were comprehensively analysed using Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Additionally, the water absorption capacity of the hydrogel was quantitatively evaluated. Furthermore, this study investigated the efficacy of AM/CMC/MB hydrogel in promoting the growth and development of potted tobacco seedlings under drought stress conditions. The results showed that the equilibrium solubility of AM/CMC/MB hydrogel was increased by 74.83 % and the diffusion process of water molecules followed the non-Fickian diffusion law compared with commercially available water retention agents. The openness of stomata of tobacco seedlings and the SPAD values were improved. The MDA (Malondialdehyde) content of tobacco seedlings was reduced by 47.50 %, CAT (Antioxidant enzymes catalase) and POD (Peroxidase) activities were increased by 198.15 % and 198.23 %, respectively. The total amount of metabolites detected after drought in tobacco seedlings supplemented with hydrogel AM/CMC/MB was increased by 50.33 % as compared to the control. This study provides a basis for the use of AM/CMC/MB as a water retention agent for tobacco growth and development.