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

Table 3

The spatial variation of root lengths and percentage root growth inhibition of A. cepa bulbs exposed to water 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	1.644 ± 0.177a	23.9	4.086 ± 0.21	11.8
B	1.743 ± 0.10	19.2	2.602 ± 0.13	43.9
C	2.113 ± 0.12	2.1	2.868 ± 0.18	38.1
D	1.996 ± 0.11	7.5	3.829 ± 0.20	17.4
E	1.792 ± 0.11	16.7	3.799 ± 0.24	18.0
F	2.159 ± 0.12	-	4.635 ± 0.19	-