Effect of Different Microwave Doses on Vicia faba
Germination, Growth and Genetic makeup
Problem:
Some areas are affected by high frequencies of microwaves; this affects
plant growth, germination and genetic makeup, which leads to a loss in
crop yield, including one of the major crops of high economic
importance, the Vicia faba.
Abstract:
Plants and their stresses have been of very great importance lately. Since
there are many kinds of stresses, we only studied one, but a very
important one: microwaves and their effect on plants. Microwaves are
going to be the focus of our study because of the drastic effects that they
have, not only on humans and different mammals but on plants. In brief,
we can say that microwaves are electromagnetic waves with wave length
longer than those of terahertz (THz) frequencies, but relatively short for
radio waves. There are lots of sites contaminated by microwave radiation
from cellular radiation, power plants and high voltage towers, etc…..
These affect the plants development, which drew our attention towards
this project.
Our hypothesis is that different doses of microwaves affect plant growth
and development. To prove this hypothesis; we have to expose plants to
different microwave doses, plant them in a green house under controlled
conditions (soil, climate, humidity …) and observe them daily. Then we
have to extract the DNA and RAPD of the DNA and determine the
changes that occurred in their genes. Our conclusion from this study is
that different microwave doses do affect plant germination.
Introduction
Plants and environmental stresses have been of most importance as a field
of study and research through out the ages. It was found that the different
stresses that plants are exposed to are outgoing and reduce the crop yield.
Of these stresses, temperature, drought, salinity and microwaves are of
major importance.
Temperature, for example, is the principal factor determining vegetation
zones. Global climate change caused by elevated greenhouse gasses was
predicted to increase the proportion of hot, semi-arid land and the
prevalence of high temperature and water stress. Oxidative stress from
UV, photo-inhibition and pollutants such as troposphere ozone are
associated problems. Drought is the main cause of low plant productivity
and particularly of seasonally erratic productivity. Water is an
increasingly continuous issue as there is not enough renewable fresh
water at the right place and time to serve humans needs, regardless to say
plants. Irrigation on demand and irrigation with poor quality water
together lead to water logging and soil salinity so undermining the
sustainability of the irrigated agriculture upon which food security
depends. These reasons lead to research focusing on increasing
knowledge of plant metabolic processes and their regulation.
Developing novel protocols for the genetic manipulation of previously
recalcitrant plant species is the most recent trend in research in regards to
the solving of such problems.
Microwaves are going to be the focus of our study because of the drastic
effects that they have not only on humans and different mammals but on
plants. In brief we can say that microwaves are electromagnetic waves
with wave length longer than those of terahertz (THz) frequencies, but
relatively short for radio waves. Microwaves have wavelength
approximately in the range of 30 cm (frequency=1GHz) to 1mm (300
GHz). The microwave range includes ultra-high frequency (UHF) (0.303GHz), super high frequency (SHF) (3-30 GHz) and extremely high
frequency (EHF) (30-300GHz) signals. Above 300 GHz, the absorption
of electromagnetic radiation by earth atmosphere is so great that it is
effectively opaque, until the atmosphere becomes transparent again in the
so-called infrared and optical window frequency ranges. Microwaves
were found to affect plants and plant growth severally. Long exposure to
microwaves affects the germination of seeds or plants. However, weak
microwaves don’t effect plant growth but as the microwave dose
increases, the rate of germination decreases.
Faba beans (Vicia faba) were found to be one of the most important
sources of nutrition, being used in animal feed and -in some poor and
developing countries- as a source of food. This very important crop is
increasingly in demand for different uses as stated. It is noteworthy that
the ability of using this crop and harvesting it in places were the
environment has been contaminated with radiation will, of course, be of
great benefit. In order to do so we need to properly identify the effect of
microwaves on the genetic makeup of vicia faba and the correlation
between that effect on both growth and germination of the beans.
Aim:
To Study the effect of microwaves in different doses on the germination,
growth and genetic makeup of faba beans.
Hypothesis:
Seed exposure to microwaves will affect the germination, growth and
genetic makeup of faba beans.
Experiment Design:
Giving the plant time for both germination and growth, we will correlate
the relation between the exposure of different doses of microwaves and
the plant germination, growth and genetic makeup. In studying that effect
on plant germination we intend to observe the plant during stage of
germination, taking in consideration parameters as time till germination,
radical position and direction of growth and the time till shoots prevail.
We put into consideration when studying plant growth the following
parameters: plant height, time till complete growth, stem morphology,
leaf morphology and the yield of the plants. Finally to correlate between
that effect and the genetic makeup of the
plants we will study the
genetic makeup of the plants and the changes that occurred according to
the different doses of microwave exposure using RAPD technique.
Experiment variables
1. Microwave doses.
2. Planting in green house at the same conditions.
3. Parameters measured according to the breeder's program
4. Plant height, time till complete growth, Plant morphology and the
yield of the plants
Materials and Equipment:1. Microwave oven was used as a source of microwaves with
frequency raging between 2.4-2.5 GHz.
2. Green house to plant the seeds to provide the same soil and
irrigation method and climate
3. Triazol DNA extraction kit
4. PCR Machine
5. Electrophoresis unit
6. Gel imaging system
7. RAPD amplification kit
Experimental Procedures:
1. Seeds were exposed to different microwave doses being studied
namely, 2.4GHz, 2.45 GHz and 2.5GHz for a one minute interval
2. Upon exposure seeds were planted in a green house, in clay soil,
being irrigated under controlled conditions with fixed climate and
humidity
3. Daily observation of seeds germination for a period of five days
4. Daily observation of plant growth for a period of 14 days
5. Changes in plant growth were recorded
6. Pods were collected from the plants and then seeds were grinded
7. Total DNA extraction was done from the grinded seeds using the
Triazol DNA extraction kit
8. RAPD of the extracted DNA using the RAPD Amplification kit.
Results:
After two weeks results were obtained, where we monitored different
plant parameters visually for both germination and growth and using
RAPD for the change in genetic makeup. The following results were
tabulated.
Plant Germination
parameters
Control
Time till germination
Direction of growth
Time till shoots prevail
Plant height after
complete growth (cm)
Time till complete
growth (day)
2.40
2.45
2.50
1 day
2 day
3 day
Under
the
soil
Slightl
y bent
Under
the
soil
Under
Under the
the
soil
soil
Straig
Straight
ht
Radical position
Plant Growth
parameters
1 day
Microwave Dose (GHz)
3 days
lateral
3 days 4 days 5 days
Microwave Dose (GHz)
Control
2.40
2.45
2.50
18
18
16
14
7
9
12
14
Stem morphology
Normal
Normal
Normal
Curved
Leaf morphology
Normal
Normal
Normal
Smaller
leaves
Plant yield (pods)
7
6
6
4
1
2
3
Figure 1: Gel image of RAPD of the plants after being subjected to three
different doses of microwaves 2.4 (1), 2.45 (2) and 2.5 (3). The
arrow here indicates the molecular weight at which the new
bands appeared proving the alteration of the genetic makeup of
the faba beans upon exposure to different microwave doses.
Conclusion:
Different microwave doses do affect the germination, growth and genetic
makeup of Vicia faba beans.
Application:
Under microwave stress, changes occur to the yield. Plants don't die but
new bands appeared. Using these bands we can introduce new characters
to plants that are present in regions that are contaminated with different
microwave frequencies. When these bands become isolated, identified
and sequenced we will use them to increase the resistance of plants that
are cultivated in areas under microwave stress.
Discussion
To Study the effect of microwaves on plants was the main purpose of my
study. Since it is a known problem, many other researches were done on
this topic. Having seen and observed other projects, we noticed that the
major conflict was between whether microwaves affect plants
germination or not. Our hypothesis was that they do affect it and, of
course, it is well known that they do but it still made a challenge trying to
prove it and it was found that every single step affected the results. Since
it is likely that other people who did similar projects have done some
errors through their study, the results were not reliable and could not be
considered accurate enough.
However, at the end of our study the results showed that low microwave
doses do not affect plant germination, meaning that as the microwave
dose increases, the rate of germination decreases.
References:
http://en.wikipedia.org/wiki/Microwave
http://en.wikipedia.org/wiki/Beans
http://en.wikipedia.org/wiki/RAPD
http://www.johnstonsarchive.net/environment/cellphone.html
http://en.wikipedia.org/wiki/Global_warming