Exogenous Application of Multi-Walled Carbon Nanotubes (MWCNTs) and Nano-Selenium (Nano-Se) Alleviated the PEG-Induced Water Deficit Stress and Improved the Crop Performance of Camelina

While previous studies have shown camelina drought tolerance relative to other oilseed crops, drought has been documented to severely influence the productivity of camelina. To date, little information is available on the drought tolerance of camelina genotypes. This study was conducted to evaluate drought tolerance in fifteen camelina genotypes and test the alleviative effect of nanoparticles on PEG-induced water deficit stress (WDS) at the whole-plant level at the Yangzhou University Pratacultural Science Experimental Station in September 2021. Four different degrees of WDS were induced by a range of PEG solution concentrations (0, 16.7, 25.0, 37.5, and 56.3 mM). A petri dish study determined that CamK8 and CamK9 (GR(50) = 19.0 and 34.3 mM, respectively) were the most sensitive and tolerant genotypes, respectively, to PEG-induced WDS. Results from the whole-plant test showed that the foliar application of MWCNTs (dose: 50 or 100 mg L-1) or nano-Se (dose: 5 or 10 mg L-1) alleviated the adverse effect of PEG-induced WDS, and increased the camelina plant height (ranges: 51.1-56.3 cm) and crop yield (ranges: 0.11-0.14 g plant(-1)) compared with untreated control and PEG-treated plants (height: 43.5-56.9 cm; yield: 0.06-0.12 g plant(-1)) in CamK8 without affecting the principal fatty acid composition and groups in camelina oil. The results of this study demonstrated that applying MWCNTs or nano-Se could alleviate WDS and maintain seed yield in camelina, providing the possibility of using these nanoparticles to manage WDS in agricultural practices.