GA3 and KNO3 Efficiency of Breaking Dormancy In Wild Brassicaceae (Brassica napus and Raphanus raphanistrum) Seeds for Enhanced Phytoremediation

Abstract

Brassicaceae family are largely stress resistant to extreme environmental conditions particularly heavy metals laden soils. They are found in post-harvest agricultural field and sometimes during farming season costing economic loss to farmers. The species, Raphanus raphanistrum (wild radish) and Brassica napus (canola) were collected from agricultural fields within the University of Eldoret farmlands. The morphometric characteristics, longitudinal length, transverse length (width), perimeter, areas, and seed weight were assessed. Matured seeds within siliques were sundried in a glasshouse (25-45°C) for several days until constant weights were obtained. About a hundred seeds of each, wild radish and canola were mechanically removed and portioned into five germination test groups. The seeds presoaked in distilled twenty-four hours before treatment with plain water (control), concentrated acid solutions (H2SO4 and HCL 5 minutes and 30 minutes, respectively), Chilling at 4°C, 0.25mg/mL Gibberellic Acid (GA3), and 0.1% alkaline (KNO3). Pretreated seeds were transferred into sterilized petri dishes containing double-layer filter papers. The germination experiments were carried out in biotechnology lab at 20-25oC under normal lightening. In all setups, germination was effective in Brassica napus yielding 80% and 90% germination rate for GA3 and KNO3, compared to Baphanus raphanistrum, 70% and 10%, respectively. Priming with H2O, H2SO4, HCL, and chilling were ineffective in this trial