Cytogenetic effects of chitosan-capped silver nanoparticles in the Allium cepa test

Figures & data

Figure 1. (Color online) Atomic force microscopy (AFM) image of AgNP.

Figure 2. (Color online) Stages of mitosis in the meristematic cells of A. cepa: (a) prophase; (b) metaphase; (c) anaphase; (d) telophase.

Table 1. Data on mitotic and phase indexes (mean ± SD) in the meristematic cells of A. cepa roots treated with solutions of silver nanoparticles.

AgNP concentration (mg l^–1)	Mitotic index, %	Phase index, %
		Prophase	Metaphase	Anaphase	Telophase
Control (0)	10.15 ± 0.38	53.39 ± 0.65	20.26 ± 0.72	13.06 ± 0.46	15.93 ± 1.26
1	10.55 ± 0.27	54.38 ± 1.25	19.14 ± 1.13	12.57 ± 0.87	13.91 ± 0.70
2.5	11.27 ± 0.40	53.69 ± 1.40	19.36 ± 1.24	12.91 ± 0.94	14.04 ± 0.79
5	12.18 ± 0.56^*	55.28 ± 1.11	19.32 ± 0.55	11.74 ± 0.86	13.66 ± 1.05
50	17.20 ± 0.50^*	62.55 ± 0.88^*	25.45 ± 0.67^*	5.06 ± 0.43^*	6.95 ± 0.45^*

^* Statistically different when compared with the untreated control.

Figure 3. (Color online) Control meristematic cells of A. cepa.

Table 2. Data on the number of mitotic disturbances (mean ± SD) in the meristematic cells of A. cepa roots treated by AgNP.

AgNP concentration (mg l^–1)	Mitotic abnormalities, % per 1000 cells
	Polyploidy	Lagging chromosomes	Total, %
Control (0)	0.00	0.05 ± 0.02	0.05 ± 0.02
1	0.00	0.02 ± 0.01	0.02 ± 0.01
2.5	0.00	0.03 ± 0.02	0.03 ± 0.02
5	0.03 ± 0.01^*	0.05 ± 0.01	0.08 ± 0.02
50	5.45 ± 0.62^*	0.27 ± 0.02^*	5.72 ± 0.60^*

^* Statistically different when compared with the untreated control.

Figure 5. (Color online) Giant polyploid cells (prophases, telophases and interphases) in root meristem of A. cepa after incubation in solution of 50 mg l⁻¹ AgNP.

Figure 4. (Color online) Giant polyploid cells (anaphases and interphases) in root meristem of A. cepa after incubation in solution of 50 mg l⁻¹ AgNP.

Table 3 Data on the number of chromosomal aberrations and micronuclei (mean ± SD) in the meristematic cells of A. cepa roots treated with colloidal solutions of silver nanoparticles.

AgNP Con. (mg l^–1)	Chromosomal abnormalities, % per 100 ana-telophases			Micronuclei, % per 3000 cells
	Bridges	Fragments	Total, %
Control (0)	0.40 ± 0.16	0.20 ± 0.11	0.60 ± 0.16	0.011 ± 0.004
1	0.27 ± 0.12	0.20 ± 0.14	0.47 ± 0.17	0.013 ± 0.004
2.5	0.40 ± 0.13	0.40 ± 0.24	0.80 ± 0.26	0.011 ± 0.004
5	0.60 ± 0.29	0.47 ± 0.23	1.07 ± 0.34	0.018 ± 0.006
50	2.47 ± 0.46^*	2.13 ± 0.23^*	4.60 ± 0.53^*	0.118 ± 0.014^*

^* Statistically different when compared with the untreated control.

Figure 6. (Color online) Mitotic and chromosome abnormalities and micronuclei in root meristematic cells of A. cepa: bridges (A, B), acentric fragment (C), double fragments (D), lagging chromosomes (E, F) and micronuclei (G, H).