Impact of Single or Fractionated Radiation and Selenium Nano-particles on Acid Lime (Citrus aurantifolia L.) Seed Germination Ability and Seedlings Growth

Abstract

In the present study, seeds of acid lime (Citrus aurantifolia L.) were radiated with gamma radiation at low dose of 20 Gy as single dose or fractionated doses, part of radiated seeds were soaked in solutions of Nano-selenium at 50 ppm , to investigate the effect of treatments on seeds germination ability , seedlings vegetative growth parameters, leaf bio- chemical contents and leaf (macro & micro) elements, moreover, separation of HMW and LMW protein subunits extracted from all consequent seedling was performed using electrophoresis technique. Obtained results revealed generally that pre-sowing radiation of acid lime seeds with γ radiation at 20 Gy , fractionated as 4 doses or as 2 doses and then, soaking irradiated seeds in Nano-selenium solution at (50 ppm) treatment, increase germination percentage by 30% and 36% compared with untreated seeds (control) for both seasons, as well as reduced seedlings damping off and albino percentage, and increased seedlings stem length by 52.5% & 46.5 %, and stem diameter by about 37% and 36% , also number of leaves/ seedling and leaf area was significantly increased, also cause significant increase in total indoles and reduced total phenols content in acid lime seedling leaves. In addition, both γ ray and Nano-(Se) treatment significantly increase accumulation of macro and micro-elements which positively reflected on seedlings vegetative growth. Protein analysis using electrophoresis technique for acid lime seedlings leaves illustrated that, exposure of acid lime seeds to different doses of γ ray showed clear separation of protein pattern with no differences with untreated samples (control), which means that acid lime seeds, could be treated with particular low doses gamma radiation without affecting the genotype. Briefly, pre-sowing combination treatments of both γ radiation treatment and soaking in Nano-selenium solution at 50 ppm, could be helpful in, reducing nursery period and producing vigorous and healthy (acid lime seedlings) with improved quality