A Combined Approaches of Biochar and ZnO Nanoparticle-Based Nanopriming for Enhancement of Wheat (Triticum aestivum L.) Seed Germination Indices Under Salinity Stress

Abstract

Soil salinization is a significant ecological issue that reduces soil fertility, inhibits plant growth, and decreases crop productivity. The impact of biochar and ZnO nanoparticle (ZnO-NP) based nanopriming on early seedling growth in wheat under salinity stress was investigated. Experimental trials were conducted in (i) a soil-based bioassay under greenhouse conditions with 1.3% (w/w) biochar, (ii) a greenhouse seed bioassay to assess the effects of ZnO-NPs, and (iii) at different concentrations of biochar and ZnO-NPs (50 mg/L and 100 mg/L), either alone or in combination, to determine which treatment was most effective under varying salinity levels (low, medium, and high) for wheat genotypes (V1: Gohar and V2: Van). Results showed that germination rate (GR), germination percentage (GP), mean daily germination (MDG), germination vigour index (GVI), stress tolerance indices including PI and GSTI, as well as seed content, were significantly reduced by increasing salinity levels. The V1 (Gohar) genotype showed that the combined application of 1.3% biochar and 50 mg/L ZnO-NPs was most beneficial for seed germination; in contrast, the V2 (“Van”) genotype responded best to individual treatments of either 1.3% biochar or ZnO-NPs at 50 or 100 mg/L, depending on the salinity level. Overall, the V2 genotype exhibited the highest salinity stress tolerance. These findings demonstrate that biochar and ZnO nanoparticles, applied separately or together, have great potential for improving wheat seedling establishment in saline environments. The research highlights the emerging role of biochar and pre-sowing nanopriming in the agro-industry for soil enhancement, stress management, and crop productivity.