In this study, biological test using allium cepa L. and white onion was carried out to monitor the quality of groundwater sample. The two species of onions were subjected to different concentrations of heavy metal and their mean daily root growths were measured after 24hrs, 48hrs, 72hrs and 96hrs. Results indicate that a linear relationship exists between the percentage root growth inhibition and different metal concentrations (0.3mg/l, 0.5mg/l, 0.7mg/l, and 0.9mg/l) in Allium cepa L. species. Root growth inhibition increased with increase in metal concentration and duration of exposure. The highest root growth inhibition (91.4%) was observed at 0.9mg/l concentration of iron metal. For the white onion species, a non-linear relationship existed and does not follow any sequence. Hence, it is not a good indicator for monitoring water quality while bioassay using Allium cepa L. as indicators is a useful screening test for the evaluation of toxicity of heavy metal and can be used to support chemical analysis.
Allium cepa, White onion, Bio indicators, Root growth inhibitor
Nwajuaku I. I , Nweke C. N "Comparative analysis of allium cepa l. and white onion as bio indicators of heavy metals in groundwater" Iconic Research And Engineering Journals Volume 3 Issue 3 2019 Page 96-101
Nwajuaku I. I , Nweke C. N "Comparative analysis of allium cepa l. and white onion as bio indicators of heavy metals in groundwater" Iconic Research And Engineering Journals, 3(3)