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where the units of WHC are expressed in g kg
-1
. The amount of chlorophyll was measured
with a Minolta SPAD-502 Chorophyll meter (Markwell et al., 1995). The Fe, Ti, and Zn were
determined by inductively coupled plasma mass spectrometry (ICP-MS).
Statistical Analysis
The data were subjected to an analysis of variance and means compared with the Tukey
test using Statistical Analysis System (SAS) software version 8.0 for Windows (SAS
Institute, 1989). Soil and plant characteristics were subjected to a one-way analysis of
variance using a general lineal models procedure (PROC GLM) to test for significant
differences between treatments (
P
< 0.05). All analyses were performed using the SAS
statistical package (SAS Institute, 1989).
R
ESULTS AND
D
ISCUSSION
Nanoparticles are adsorbed by plant surfaces through natural nano- or micrometer-scale
plant openings (Dietz and Herth, 2011). During the germination and seedling emergence,
these nanoparticles could decrease some plant characteristics. We found no significant effects
of nanoparticles on the germination rate when seeds of basil, coleus, sweet alyssum, common
bean, sunflower, and maize were sprayed with magnetite (Fe
3
O
4
) or hematite (Fe
2
O
3
)
nanoparticles at increasing concentrations (Figure 1). However, Dehkourdi and Mosavi
(2013) showed that an increase in the concentration of nano-anatase caused a significant
increase in the percentage of germination, germination rate index, root and shoot length, fresh
weight, vigor index, and chlorophyll content of seedlings of parsley (
Petroselinum crispum
).
Parsley's seed germination takes much longer than that of most vegetables. It is quite difficult
to be germinated (the germination percentage is at 55%-75%, it is lower than the average
germination percentage), especially under unfavorable environmental conditions. Their
results showed that an increase in the concentration of nano-anatase caused a significant
increase in the percentage of germination, germination rate index, root and shoot length, fresh
weight, vigor index, and chlorophyll content of seedlings. The best concentration of nano-
anatase was 30 mg mL
-1
.
In recent months, nano priming has become a new method for increasing seedling vigor
and improving both germination percentage and seedling growth. The effects of nano-TiO
2
(rutile) and non-nano-TiO
2
on the germination and growth of naturally aged spinach seeds
were studied. An increase of these factors was observed at 0.25-4‰ nano-TiO
2
treatment
(Zheng et al., 2005). Although Feizi et al. (2012) reported that nano-TiO
2
in a suitable
concentration could promote the seed germination of wheat in comparison to bulk TiO
2
, in
high concentrations, it had inhibitory or no effects on wheat. Similar results were reported by
Castiglione et al. (2011), who studied the effect of nano-TiO
2
on the seed germination,
development, and mitosis of root tip cells of
Vicia narbonensis
L. and
Zea mays
L. They
found that root elongation was affected only after treatment with the highest nano-TiO
2
concentration (4.0 parts per thousand), while further significant effects were detected,
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