Radiation comes in different forms including electromagnetic waves and particulate matter. Ionizing radiation comes from unstable atoms and includes alpha particles, beta particles, gamma rays, x-rays, and neutrons. Exposure to ionizing radiation can cause DNA damage in plants and induce mutations, leading to effects like reduced growth, reproduction, and seed germination. While some low doses of radiation have been used to improve crops, high doses can kill plants or negatively impact their productivity and genetic structure. Infrared radiation also influences plant growth and development processes like blooming and stem elongation but too much can damage plants through heat.
5. Ionizing radiation is produced by unstable atoms.
Unstable atoms differ from stable atoms because
they have an excess of energy or mass or both.
Unstable atoms are said to be radioactive. In order
to reach stability, these atoms give off, or emit,
the excess energy or mass. These emissions are
called radiation.
6.
7. Higher energy electromagnetic waves (gamma) or
heavy particles (beta and alpha). High enough
energy to pull electron from orbit
Types :
Alpha particles
Beta particles
Gamma rays (or photons)
X-Rays (or photons)
Neutrons
8. Alpha Particles: 2 neutrons and 2 protons. They travel
short distances, have large mass ,Only a hazard when
inhaled
Beta Particles: Electrons or positrons having small mass
and variable energy. Electrons form when a neutron
transforms into a proton and an electron.
9. Gamma Rays (or photons): Result when the
nucleus releases energy, usually after an alpha,
beta or positron transition
X-Rays: Occur whenever an inner shell orbital
electron is removed and rearrangement of the
atomic electrons results with the release of the
elements characteristic X-Ray energy
Neutrons: Have the same mass as protons but
are uncharged
10.
11. Chromosomal aberrations
Visually observable changes in chromosomes
structure.
DNA damage
Any damage to DNA molecules ,including DNA
sequence “ inversion ” TCAG now GACT as well as
sections of sequences deleted .
12. Growth reduction
Reduction in the rate of growth of plants
Reproduction effects
Including sterility , reduction in reproduction
rate and occurrence of abnormalities or
reduction in viability of plants.
Reduced seed germination
Mortality , including both acute lethality and
long term reduction in life span
Direct burn damage to exposed tissues
13. Direct contact with radiations is not required
to effect local plant life , the mere presence
of reactor is often enough.
To build a nuclear reactor, one requires a
great deal of space , usually near water,
which means clearing out any local
vegetation.
Heat given off by the reactor can change
nearby water temperature, disturbing the
delicate conditions required for coastal
vegetation.
14. Because ultraviolet radiation destroys cells,
the chance of mutation are great.
Affected plants are often small and weak with
altered leaf patrens.
15. Prolonged radiation can completely destroy
the fertility of plant. The plant gradually dies.
The surroundings become poisoned and
prevent the growth of future offspring.
Not all radiation is bad . Sunshine is a type of
radiation that is needed for photosynthesis
and normal plant growth.
16. Ultraviolet radiations affects plant growth and
development in many ways. First, it gradually
stops seed growth and sprouting, depended
on the how much radiation is released. Soil
can become compacted and lose the nutrients
needed for plants to grow.
The results of various lab experiments
supplying ultraviolet radiation through
filtered lamps proved that higher doses of
radiation administered to plants were very
damaging
17. The stomata is small air hole within the leave
of plant that control the water levels.
If there is to much evaporation due to the
intense radiation, the stomata closes to
reserve water. If the stomata is unable to
open for a long period of time, the growth of
plant is stunted.
Prolonged periods of radiation can completely
damage the stomata and destroy the plant.
18. The cells of living organism are also damaged
and killed by ultraviolet radiation.
What allow plants to grow is the division and
expansion of cells as they take up water.
Cell contains chromosomes, the genetic
material responsible for plant reproduction. If
the cell is overly damaged by radiation, then
reproduction is hindered
19.
20. Consist of unstable atoms or radio nuclides which
decay spontaneously and change into different
types of atoms
Contains different form of energy particles such as
Alpha , Beta ( electrons), gamma, protons and
neutrons.
Alpha radiation is non penetrating but dangerous if
emitted inside the body
Beta radiation can penetrate and cause non healing
effects
Gamma radiation is highly penetrating have high
energy particles like x rays
21. Hazardous effects of nuclear radiation are
generally caused by these gamma rays and
plants are extremely sensitive to gamma
radiation
Higher plants show wide range (5-500
rads/day) of radio sensitivity
22. Nuclear radiation induces versatile changes in plant
system at morphological, cellular, metabolic and
genetic levels
Plants response to irradiation varies according to
age, growth stage, plant species, chromosomes
volume and high or low dose of radiation
Effects of radiations on plants near Chernobyl
accident site, structural distortion or swelling in
endoplasmic reticulum, Thylakoid membranes,
mitochondria, cell wall , and plasma membrane of
plant cells has been observed in vitro conditions
(national geographic magazine august 1994)
23. Alterations in plant vascular system, water
transport and other cellular functions have also
been found. These changes are usually irreversible
and retained after radiation has stopped.
Foliage can get readily contaminated with
radioactive substances and if ingested by
herbivores; they are automatically exposed to
radiation and suffer from its possible effects .
thus in particular food chain, radiation of dose of
contaminated producers can reach up to tertiary
consumers via primary and secondary consumers.
24. Germination of seeds that have been exposed
to radiation may show retarded growth,
increased mortality and decreased percent
germination.
Radiation exposed seeds or seedlings have
differed morphological characteristics
25. Alpha beta gamma rays of nuclear radiation
are energetic enough to detach electrons
from atoms or molecules thus ionizing them.
Generation of free radicals which can damage
or mutate DNA even at room temperature is
the major property and primary cause of
danger by these ionizing radiations
Radiation induced genetic mutations can
change plant vigor which in turn negatively
affects plant productivity.
26. Nuclear radiation induced mutations and DNA
damage usually results in irreversible
phenotypic and genotypic changes in particular
plant species. And is directly proportional to
intensity and of exposure
If plant in its embryonic state is exposed to
radiation, mutational changes like infertility
increased disease susceptibility, reduced
germination frequency, flowering, pod maturity
and decreased grain / straw yield can be very
harmful.
27. However, we should not forget that some
nuclear radiations as gamma particles at
defined doses have been utilized in crop
improvement protocols with interesting
useful results such as increased disease
resistance, vigor, and high productivity.
It also effects the growth hormones .
28. Gigantism, dwarfism, abnormal rapid growth
underdeveloped root system or curly and
misshaped leaves are some of the changes
showed by the growing plants after exposure
to low doses of radiations.
Higher dose can kill the plants of similar or
different species
Radiation inhibit the germination and
responsible for DNA damage in embryonic
state.
29. Nuclear radiation emits from uranium,
radium, and radon found in the earth crust
30. Blooming
• Infrared light plays a part in the blooming of
flowering plants.
• Plants grown indoors may grow well under
fluorescent lights, but will not bloom until
appropriate levels of infrared radiation have
been introduced. This can be done using
special horticultural lights, or simply by
adding incandescent light bulbs.
31. Stem
• Increased infrared rays can effect the speed at
which plant stem grow.
• A short exposure to far infrared light increased the
space between nodes when the exposure occurred
at the end of an eight hour light period. Exposing
the plants to ordinary red light reversed this effect.
• A combination of far red and red light produced
the longest internodes.
• Plants grown in light that is too red may seem
spindly and long stemmed
32. Damage
• Too much infrared light, especially in the far
red end of the spectrum, may actually
damage plants
• Heat may discolor or kill plants, especially if
those plants have not recently been watered.
• Too much infra red light may also cause
plants to experience early growth spurts that
reduce their health, or encourage them to
early flowering .
