In this study, the role of the signalling molecule nitric oxide (NO) in magnetopriming-mediated induction of salinity tolerance in soybean seeds is established. The cross-talk of NO with germination-related hormones gibberellic acid (GA), abscisic acid (ABA) and auxin (IAA) for their ability to reduce the Na⁺/K⁺ ratio in the seeds germinating under salinity is highlighted. Salt tolerance index was significantly high for seedlings emerging from magnetoprimed seeds and sodium nitroprusside (SNP, NO-donor) treatment. The NO and superoxide (O₂^•−) levels were also increased in both of these treatments under non-saline and saline conditions. NO generation through nitrate reductase (NR) and nitric oxide synthase-like (NOS-like) pathways indicated the major contribution of NO from the NR-catalysed reaction. The relative expression of genes involved in the NO biosynthetic pathways reiterated the indulgence of NR in NO in magnetoprimed seeds, as a 3.86-fold increase in expression was observed over unprimed seeds under salinity. A 23.26-fold increase in relative expression of NR genes by the NO donor (SNP) was observed under salinity, while the NR inhibitor (sodium tungstate, ST) caused maximum reduction in expression of NR genes as compared to other inhibitors [L-NAME (N(G)-nitro-L-arginine methyl ester; inhibitor of nitric oxide synthase-like enzyme) and DPI (diphenylene iodonium; NADPH oxidase inhibitor)]. The ratio of ABA/GA and IAA/GA decreased in magnetoprimed and NO donor-treated seeds, suggesting homeostasis amongst hormones during germination under salinity. The magnetoprimed seeds showed low Na⁺/K⁺ ratio in all treatments irrespective of NO inhibitors. Altogether, our results indicate that a balance of ABA, GA and IAA is maintained by the signalling molecule NO in magnetoprimed seeds which lowers the Na⁺/K⁺ ratio to offset the adverse effects of salinity in soybean seeds.

Onion seeds are prone to rapid germination and viability losses under unfavourable storage conditions. The final germination percentage is considered the most important parameter for determining the performance of seed lots after storage, although other quantitative traits, such as the time and speed of germination, help in more realistic predictions of seed germination. A study was conducted on seventeen seed lots of onion seeds to delineate the most comprehensive parameter indicating seed performance after storage using the four-parameter Hill function (4-PHF) mathematical model. Seeds of seventeen onion cultivars were subjected to accelerated ageing at 42 °C and 100% RH for 48, 96 and 144 h, followed by seed germination evaluation. The germination performance was evaluated by 4-PHF based on time-related parameters, such as the time to maximum germination rate (TMGR), time to 50% germination (T₅₀), and uniformity (U), along with the germination percentage (a), shape and steepness of the Four-Parameter Hill Function (FPHF) curve (b), which were important determinants of the area under curve (AUC), and RoG (rate of germination) curves. Among the parameters, the AUC was found to provide the most comprehensive evaluation of the storage performance of the onion varieties and was decisive in the classification of the varieties as ‘good’ or ‘poor’ storers. A positive correlation between seed vigour index-I (SVI-I) and the AUC reiterated the suitability of using 4-PHF parameters for the assessment of the storage potential of onion varieties.

Climate change has an impact on agriculture and insect pests that affect the crop production. Aphid pests occur throughout the temperate region of the world andcause direct damage by sucking plants sap which affects growth and yield of the crops. Species of aphids are diverse and ubiquitous but their importance among crop differs.Ultraviolet radiation (UVR) is an electromagnetic radiation and constitutes about 10% of the total light output of sunlight. Ultraviolet-B coming due to ozone depletion is the most photo chemically reactive wavelength of solar radiation and important stressor to organisms particularly in their early stages of life and affect ecosystem. Psoralene and alpha- terthienyl are naturally occurring plant metabolites found in many crops and become photo reactive in presence of solar ultraviolet- B radiation. Measurement of solar ultraviolet radiation (UV-B and UV-E) was performed in Garhwalregion of Uttarakhand. Morphological, behavioural changes, mortality rate and glutathione contents were observed in mustard and roseaphids after ultraviolet-B irradiation with psoralene and α-terthienyl photo sensitizers. UV-B and UV-E radiation showed seasonal, diurnal and altitudinal variations. α- terthienyland psoralenewith ultraviolet-B radiation showed stunted growth, morphological changes, low reproduction and high mortality up to 26% in aphids. Reduction in glutathione (GSH) level in aphids was also observed after UV- B and photosensitizersexposure.Enhanced UV-B was found more toxic with photosensitizers andthus, can be used as natural insecticide. Dose, intensity and species dependent changes in toxicity of psoralene and α- terthienyl were observed in aphids. Resultsindicate that UV-B radiation with photosensitizers has toxic effect on aphids population, dispersal and diversity. Psoralene was found more toxic than α- terthienyl in aphids. Mustard aphid (Lipaphis erysimi) was found more sensitive than rose aphid (Macrosiphum rosae).

Onion varieties were classified into different storability groups by comparing two approaches (i)germination and vigor indices (conventional germination parameters) (ii)variables extracted from 4 Parameter Hill Function (4-PHF), after mimicking ageing conditions with accelerated ageing (42 °C and 100% RH). The study revealed that in comparison to evaluation using conventional germination parameters, the parameters extracted using 4-PHF provided realistic characterization of varieties as good, medium and poor storers. Time related parameters like time to maximum germination rate ( TMGR ), time to 50% germination ( T ₅₀ ), difference between time at germination onset ( lag ) and 50% germination ( D _lag-50 ), uniformity ( U ) along with germination percent ( a ) and area under curve ( AUC ) were decisive in identification of the varieties to a storage category which was misinterpreted with exclusive use of conventional approach. The distinction between good and medium storers was not of much significance but shift of varieties like Bhima Super, Pusa Red and Agrifound Light Red from poor to good performance cluster could be detected exclusively through 4-PHF analysis. Curve fittings highlighted AUC as the most crucial parameter contributing towards clustering of the varieties in different storability groups. Our study is the first reported research of using 4-PHF mathematical function for seedlot characterization into different storability groups.