The increased lead (Pb) content in the environment has an impact on all living beings, including plant growth and quality. The present study aims to investigate the protective roles of zinc (Zn)- and iron (Fe)- nanoparticles (NPs) in alleviating stress symptoms caused by lead (Pb) exposure in Basella alba seedlings. For this purpose, 15 different treatment combinations of seed priming with two NPs at 0 and 200 mg L⁻¹, and five Pb levels (0, 4, 8, 15, 20 mM) were chosen. Pb stress (20 mM) was found to reduce seed germination by 72.8% and seedling growth, particularly root length, by 92% when compared to the control. Under different Pb concentrations, seed priming with ZnNPs (200 mg L⁻¹) and FeNPs (200 mg L⁻¹) increased seed germination by 34.7% and 54.9%, respectively, and root length by 152.9% and 252.9%, respectively. In 20 mM Pb stress, NPs primed seedling showed decrease in Pb content by 33.7% with ZnNPs and 32.6% with FeNPs. Increased Pb stress resulted in increased reactive oxygen species (ROS) generation (H₂O₂) and lipid peroxidation (MDA) compared to non-Pb stressed seedlings. However, increased antioxidants in the NPs treatments such as SOD, CAT, POD and proline content, scavenged these ROS. Considering all the parameters under study, priming alleviated Pb stress in the following order: FeNPs > ZnNPs > hydropriming > control. To summarise, seed priming with Zn- and Fe-NPs has the potential to alleviate Pb toxicity via reduced Pb uptake, ROS generation and lipid peroxidation as well as increased proline content and activation of antioxidant enzymatic system.

Nutritionally rich cucumber seeds remain in demand in the agricultural, health and cosmetic sectors as they are essential for a successful crop stand establishment and seed-based products. However, the production of cucumber seeds is impeded by source limitation and nutrient deficiency. The foliar application of micronutrients can supplement this deficiency and overcome the physiological setback. An experiment was undertaken to compare the impacts of the foliar application of Fe and Zn, as nanoparticles and fertilizers, on the yield and seed quality of cucumber under open and protected environments. A foliar spray of nano-ZnO (ZnNPs) and nano-Fe₃O₄ (FeNPs) at 100, 200 and 300 mg L⁻¹, as well as ZnSO₄ and FeSO₄ as fertilizer (0.5%), was conducted at the vegetative stage and pre- and post-flowering stages. The NPs had a greater efficacy in an open field than in the protected (naturally ventilated poly house) environment. The application of both NPs increased seed yield (51.7–52.2%), total chlorophyll content (15.9–17.3%) and concentration of Zn and Fe in the fruit and the seed, by 2.0–58.5% and 5.0–30.5%, respectively. A significant increase in starch, soluble proteins, soluble sugars and oil content was observed in the seeds from the NP treated plants. NP treatment also enhanced the germination-related parameters, such as percent germination (16.8–17.0%), rate of germination (18.0–22.2%) and seedling vigor (59.8–72.6%). The biochemical characterization showed a significant improvement in the seed water uptake and the activity of hydrolytic enzymes (amylase and protease) in the germinating seed. The involvement of reactive oxygen species (superoxide anion and hydrogen peroxide) and antioxidant enzymes (Superoxide dismutase, Catalase and Peroxidase) in the germination process was indicated by an increase in their activities in the seeds from NP treated plants. Hence, the study proposes the potential benefit of the foliar application of 300 mg L⁻¹ ZnNPs and 200 mg L⁻¹ FeNPs at crucial stages of plant growth to improve the yield and seed quality in cucumbers.

Malabar spinach (Basella alba L.) belongs to the family Basellaceae which is native to Southeast Asia. It is widely cultivated as a perennial leafy vegetable in India. The leaves are rich sources of vitamin A, vitamin C, iron, calcium, soluble fiber and protein per calorie. It possesses immense potential in androgenic and nephroprotective activity, antioxidant and antibacterial activity, anti-inflammatory activity and central nervous system (CNS) depressant activity (Kumar et al. 2013). During the period of August to October2016, plants were observed with charcoal rot symptoms at Research Farm of ICAR- IIVR and in six farmers’ fields ranging in size from 200 to1000 m2 in Varanasi district of Uttar Pradesh, India. The symptoms, observed on 30 to 40% of the plants, consisted of brownish to black discoloration at the collar region of the stem and branches that progressed into wilting and drying of entire plant. Infected plant stems appeared shredded and contained black microsclerotia. Symptomatic plants were...

One fruit/vine (T1) recorded higher seed quality (germination, and vigour) with compromised seed yield (assimilate transfer, total number of sees/fruit, total number of filled seeds/fruit, seed yield/plant and 1000-seed weight) than those to two fruits/vine (T2), whereas, the three fruits/vine (T3) recorded significantly lower both seed quality and yield in two cucumber varieties (Pusa Barkha and Pusa Uday) under both open field (E1) and protected (E2) environments, during 2019, at ICAR-IARI, New Delhi. Total soluble sugars, total soluble proteins, starch and oil contents in seeds were maximum with T1. The ROS (O_2- and H₂O₂) and antioxidant enzymes (SOD, CAT and POX) were increased with the increased fruit load/vine, indicated the physical and physiological status of seed. Seed dormancy was not influenced by the number of fruit load but influenced by its genotype. Therefore, retention of two fruits per vine was recommended to get better seed yield with optimum seed quality.