Allium cepa Bio Assay to Assess the Water and Sediment Cytogenotoxicity in a Tropical Stream Subjected to Multiple Point and Nonpoint Source Pollutants

Table 4

The spatial variation of root lengths and percentage root growth inhibition of A. cepa bulbs exposed to sediment elutriate samples collected from study sites. Data are presented as mean ± SD. Results indicated by different superscript letters in each column are significantly different from each other (ANOVA, Tukey’s test, p < 0.05, n=5).

Site	48-Hour exposure		7-Day exposure
	Mean root length	% growth inhibition compared to reference site	Mean root length	% growth inhibition compared to reference site
A	2.158 ± 0.12	12.2	4.037 ± 0.20	13.4
B	1.823 ± 0.17	25.8	2.600 ± 0.18	44.2
C	1.728 ± 0.10	29.7	1.875 ± 0.15	59.8
D	2.162 ± 0.10	12.0	4.022 ± 0.11	13.7
E	2.184 ± 0.11	12.4	3.830 ± 0.20	17.9
F	2.458 ± 0.33		4.664 ± 0.19