Search

Drought stress is one of the major abiotic factors that cause a significant decline in the crop's productivity. It can disturb photosynthesis by inducing oxidative stress by producing reactive oxygen species. Recently, the use of quantum has gained the attention of scientists due to its potential positive impacts on plants under stress conditions. That's why a current study was conducted to explore the impact of Zn-quantum dot biochar (QDB) on rapeseed growth under drought stress. There were four levels of QDB, i.e., control (no QDB), 0.2 %, 0.4 %, and 0.8 %, applied on a w/w basis in soil under normal irrigation and drought stress. Results showed that 0.8 %QDB performed significantly better in improving seedling's emergence, plant height, number of branches/plants, number of pods/plants, pod length, seed weight/plant, 1000 seeds weight, and total biomass of rapeseed under normal irrigation and drought stress. At 0.2 %, 0.4 %, and 0.8 % QDB levels, the photosynthetic rate was 9.19 %, 11.78 %, and 13.46 % higher than the control under drought stress. Compared to the control, the transpiration rate increased by 61.40 % with 0.2 % QDB, 123.46 % with 0.4 % QDB, and 199.71 % with 0.8 % QDB. The percentage increase in stomatal conductance ranged from 44 % for 0.2 % QDB to 129 % for 0.8 % QDB under drought stress. In conclusion, 0.8 %QDB can potentially reduce drought stress and improve the leaf water contents and nutrient uptake in rapeseed.

Drought stress is one of the serious threats to crop production. It causes significant deterioration of crop growth and yield by inducing oxidative stress. The biochar and arbuscular mycorrhizae fungi (AMF) can be an effective technique to overcome drought stress. Activated carbon biochar (BC) has the potential to improve soil water holding capacity while AMF inoculation can increase root surface area for better uptake of water. However, their combined application as an amendment against drought still needs scientific justification. That's why the current study was conducted using a combination of AMF and BC on spinach under no drought stress and drought stress. The treatments included i.e., 0, 0.25%, and 0.50%AMF-BC. The experiment was replicated thre times using completely randomized design (CRD). Results showed that 0.5%AMF-BC increase spinach shoot fresh weight (20.34%), shoot dry weight (21.23%), shoot length (3.37%), root fresh weight (16.10%), root dry weight (14.51%), and root length (38.03%) over control under drought stress. The 0.50%AMF-BC increased chlorophyll a (15.33%), chlorophyll b (30.17%), total chlorophyll (18.85%), photosynthetic rate (35.59%), transpiration rate (26.53%), stomatal conductance (13.97%) and internal CO2 concentration (37.15%) compared to control under drought stress. The improvement in N, P, and K concentration in root and shoot verified the efficacious functioning of 0.50%AMF-BC compared to control under drought stress. In conclusion, 0.50%AMF-BC is recommended for the mitigation of drought stress in spinach.

In different heavy metals, cadmium is one of the acute toxins. It also interferes with various physiological processes in plants, such as photosynthesis, respiration, and enzyme activity. To improve the growth of plants in Cd stress, arbuscular mycorrhizae can play an imperative role. On the other hand, the use of quantum dots technology is also gaining the attention of scientists. That's why the current study investigates the effectiveness of using zinc quantum dot biochar (ZQDB) and arbuscular mycorrhizal fungi (AMF) in alleviating cadmium (Cd) stress in maize plants. The results showed that AMF+ZQDB performed significantly best at the highest level of 5Cd (5mgCd/kg soil) for enhancement in plant height (28.20 %), shoot dry weight (48.78 %), chlorophyll a (32.45 %), chlorophyll b (44.03 %) and total chlorophyll (22.02 %) compared to control (NoAMF+NoZQDB). A significant enhancement in photosynthetic rate (12.95 %) and transpiration rate (39.99 %) concentration of carbon dioxide also validated the effectiveness of AMF+ZQDB over control (NoAMF+NoZQDB) at 5Cd. For photochemical quenching decrease was 25.1 %, 2.98 %, 20.7 %, and 20.3 %, respectively, compared to the control group at 5Cd where NoAMF+NoZQDB, AMF, ZQDB, and AMF+ZQDB treatments were applied. AMF+ZQDB treatment of 5Cd showed a 30.22 % decrease in electron transport rate and 34.67 % decrease in non-photochemical quenching compared to control (NoAMF+NoZQDB). In conclusion, AMF + ZQDB is an effective amendment for alleviating Cd stress in maize by regulating biochemical and physiological attributes. Further investigations are recommended at the field level using different crops to validate the effectiveness of AMF + ZQDB as a promising amendment for minimizing Cd toxicity.