Cytogenetic effect of some nanostructure polymers prepared via gamma irradiation on Vicia faba plant

Background Nourishment plants during the field time is a must; to have healthy, high productive and self-propagating plants. The trendy nano-fertilizers came to the front in modernized agriculture seeking for minimizing the soil suffocation with other chemical fertilizers in the bulk size. Nano-fertilizers may represent a way out of shot as they are completely absorbed by plant due to their small size, also it magnifies the benefit to the plant due to its high surface area. Nano-fertilizers are introduced via different way of synthesis methods. In this work, three of new nanocomposites are prepared in nano form via Gamma irradiation from Cobalt 60 source at irradiation dose 5 KGy. These composites which can supply plants with P, Zn elements needs to be revised for their safety usage in agriculture. Methodology Three compounds; Zinc oxide, phosphorous and the mixed Zinc–phosphorous elements were prepared in nano-composite forms coated with PVP as a shell and then characterized by HR-TEM, UV and FT-IR to emphasize their new sizes and shapes, then, they were examined for their cytotoxicity in three concentrations (0.5, 1 and 2%) on Vicia faba plants; after 3 h of direct roots treatment. Cytotoxicity test concerned the mitotic index, phase index, abnormal mitosis and the type of the aberrations at each phase. Results The three tested NPs exerted mito-accelerating effect on root meristematic cells. However, concentration‐dependent genotoxicity was also an evident. Conclusion The three examined nano-composites may recommend to be used in the lowest examined concentrations to minimize its harm effect on the plant cell and keep their benefits to the environment. It also recommended to count the Zn/P mix NPs over ZN or P separately as it induces an intermediating cytogenetic effect on mitosis apparatus of Vicia faba plant. Graphical Abstract

Metabolic activity of Hordeum vulgare, Brassica napus and Vicia faba in Worm and Root type Biopore Sheaths

Aims Biopores offer favorable chemical, biological and physical properties for root growth in untilled soil layers. There they are considered as nutrient “hotspots” with preferential root growth. However, the literature lacks a quantification of metabolic activity due to nutrient acquisition of main crops while growing in the biopore sheath. Methods A pot experiment was performed to map the metabolic activity of roots, as indicated by pH change. The roots of spring barley (Hordeum vulgare L.), spring oilseed rape (Brassica napus L.) and faba bean (Vicia faba L.) were growing through the biopore sheath influenced by an earthworm (Lumbricus terrestris L.) or a taproot (Cichorium intybus L.), in comparison to subsoil without a pore (bulk soil). pH sensitive planar optodes were applied in order to image a planar section of the sheath, while preserving an intact biopore sheath during the experiment. Results Roots were first found in the field of view in worm biopore then root biopore and bulk soil. At time of the first measurement the pH value was highest in worm biopore sheath (LS-Mean±SEM: 7.16a±0.11), followed by root biopore sheath (6.99ab±0.12) and bulk soil (6.61b±0.12). In spring oilseed rape a significant alkalization (+0.80 Δ pH) was found over time in bulk soil. Faba bean significantly acidified the root biopore sheath (-0.73 Δ pH). Spring barley showed no significant pH changes. Conclusions The results of the current study reveal a trend of faster root growth through biopores and a higher initial pH value in the biopore sheaths compared to the bulk soil. Biopores serve not only as an elongation path for roots, but their sheaths also provide an environment for root activity in the subsoil.