Transcript Plant science & Biotechnology

Plant Science &
Biotechnology
Objective: Summarize the chemical
physical needs of plants of optimal
growth.
Chemical Needs of Plants
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Macronutrients needed for plant growth and
development
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Nitrogen- encourages green color and vegetative growth
in plants.
Phosphorus- encourages flowering and root growth,
necessary for reproduction and photosynthesis
Potassium- important for the development of fruit and
preparation of plants for winter
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Activates enzymes, and is more important in osmosis.
Chemical Needs of Plants
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Micronutrients or trace Elements Needed by
Plants
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Calcium, Molybdenum, Sulfur, Iron, Magnesium,
Boron, Zinc, ect.
Perform a variety of functions in plants- only small
amounts are needed, but plants will die in their
absence
Chemical Needs of Plants
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Hormones- chemical substances that control
physiological responses, including shoot and
root growth.
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Examples:
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Auxins- Indole Butyric Acid (IBA), Indole Acetic Acid (IAA)
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Promotes the formation of adventitious root growth in stem cuttings.
Cytokinins- Promotes adventitious shoot growth & elongation
Gibberrellins- Breaks seed dormancy, stimulates flowering
Physical Needs of Plants
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Water (H2O)
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Responsible for the transfer of nutrients,
maintenance of temperature, preservation of
turbidity, and necessary to carry out
photosynthesis in plants.
Absorbed by tiny root hairs scattered throughout
the roots
Large trees can absorb hundreds of gallons each
day.
Physical Needs of Plants
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Sunlight- absorbed by chlorophyll found in the
chloroplasts of the leaves and stems of plants.
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Provides an unlimited source of energy for plants.
Blue & red light spectrums are the most important in
photosynthesis.
 Green light is reflected by chlorophyll, thus of little
use for energy.
High levels of ultraviolet light damage or destroy plant
tissue
Physical Needs of Plants
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Oxygen(O2)- plants need oxygen to produce energy and for
the movement of nutrients through the plant
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Carbon Dioxide (CO2)- absorbed by plants for use in the
process of photosynthesis
Plant Science and
Biotechnology
Recognize how plants respond to
environmental stimuli
Factors affecting food Production
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Photoperiod-The amount of time a plant is exposed to
adequate light energy.
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Even momentary disruptions of photoperiod can throw off
the light cycle requirements of a plant
Photointensity- The spectrum and strength of the light
to which a plant is exposed.
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Too much light can be a bad thing and burns plants, while
too little decreases food production.
Factors affecting food Production
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CO2 Levels- needed for photosynthesis, like
oxygen for humans, often the limiting factor in
food production.
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Special generators are used to raise carbon dioxide
levels in some production greenhouses.
Factors affecting Plant Growth &
Reproduction
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Oxygen
prolonged exposure of the roots of most plants to
stagnant water will eventually “suffocate” the
plant, limit nutrient intake and stop production of
new plants.
Factors affecting Plant Growth &
Reproduction
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Nutrients
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Both macronutrients and micronutrients are needed
for plant growth and reproduction in various levels
throughout the year.
Excessive amounts of any nutrient can burn plants,
destroy cells, or prevent the absorption of other
nutrients.
Factors affecting Plant Growth &
Reproduction
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Geotropism- The directional growth of plant
roots and stems in response to the force of
gravity.
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Phototropism- The growth or response of a
plant to varying light levels.
Plant science &
biotechnology
UNIT E
Objective: Explain the fundamentals
of plant disease and infestation
Intro to biotechnology
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Fungal Diseases
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Can affect any part of a plant- break down plant
tissue.
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Easily spread by contract or spores.
Often caused from the application of water on leaves
with little airflow
Intro to biotechnology
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Bacterial infection
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Often occurs in the form of blight
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Contaminated irrigation equipment is often a cause for
the spread.
Contaminated soil can also carry bacterial pathogens.
Intro to biotechnology
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Insect Pests
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Three main types based on Mouth parts
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Sucking- damage plants by sucking juices from stems
and leaves.
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Piercing
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Ex- Aphids, whiteflies, spider mites & mealy bugs
Ex- leaf bugs & stinkbugs
Chewing
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Ex- grasshoppers, beetle larva, cicadas
Intro to biotechnology
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Japanese beetle larva and other grubs eat roots,
while adult insects and moth larva
(caterpillars/ worms in order lepidoptera) feed
on foliage.
Plant Science &
Biotechnology
Unit E
Objective: Outline biological, chemical and
physical methods of plant pest
management.
Integrated Pest management
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Program of observation and calculation used to
maximize pest control while minimizing both damage
and the use of harmful compounds and procedures.
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Limit pesticide damage to the environment.
Scouting is critical, as observation allows treatment to
proceed prior to a full blown infestation.
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Increase the effectiveness of all types of controlsparticularly non chemical treatments.
Biological Controls
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Utilize naturally occurring compounds and substances
to control plant pathogens
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Often more expensive, difficult to find, and requiring
more frequent application than chemical methods.
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Increase the value of crops when utilized in place of
chemicals.
Chemical Controls
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Center on the use of pesticides, specifically
herbicides, insecticides, miticides and fungicides used
to kill pant pests
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Most current insecticides are Organophosphate chemicals
that attack the nervous system of insects
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These chemicals quickly degrade preventing environmental buildup
and transfer. (common to former pesticides like DDT)
Chemical Controls
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Chemicals are synthetically manufactured in a variety
of forms.
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Common forms dust, wettable powder, granular, liquid,
foam.
Systemic pesticides enter the plant, and are transferred to
nearly all plant tissue.
Usually kill either by contact or digestion.
Ex- Malathion, Sevin Dust, Roundup, etc.
Physical controls
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Hand removal, destruction or capture
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Often the most cost effective and environmentally friendly,
but labor intensive and slow
Traps
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Cost effective and environmentally friendly.
Must be carefully monitored and instituted early to be
effective
EX
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Yellow sticky cards used to capture whiteflies and other
small insects in a greenhouse.
Japanese Beetle traps used pheromones (scented
reproductive hormones) to capture adult beetles.
Plant Science &
Biotechnology
Objective: Discuss the development
and utilization of virus, herbicide, and
insect resistant crops.
Biotechnology and Plant pest control
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Creating Resistant plants
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Recombinant DNA can be used to create a resistant variety
of nearly any type of plant, IF AN EDFFECTIVE GENE
FOR RESISTANCE IS KNOWN
The most effective method has been inserting gene
sequences from other resistant organisms into a DNA of the
target organism.
The Bt gene & Bt crops
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The Bt gene is used to provide plants with systemic
resistance to chewing insects responsible for
damaging leaf tissue
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Functions by causing plants to produce to toxin,
harmless to most organisms, but deadly to insect pests
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Causes internal bleeding in insect digestive systems.
Herbicide Resistant Plants
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Plants that are not affected by the use of
certain systemic herbicides.
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Allow production agriculturalists to apply
pesticides more effectively, killing weeds
without damaging plants.
Virus Resistant Plants
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Few instances of successful implementation
Usually functions by creating a protein coat
around entire virus molecules.
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Prevent virus molecules from parasitizing normal cells
Plant science &
biotechnology
Objective: Apply proper experimental
design techniques related to field plot
design and management
Approval of field trials for
transgenic Organisms
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Should be sought from APHIS
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Most often requires a significant amount of information
produced from controlled trials in a contained environment.
A plan for the trial, including practices to prevent the
spread of genes from the organism must also be developed
Agencies involved in the regulation and monitoring
of transgenic organism fields trials include the
USDA, EPA, & APHIS
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The FDA regulates GMO’s used in foods, but do no play
any role in field trials .
Implementing integrated Pest
management
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Guidelines
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Plans should include as little dependence on
harmful chemicals as possible.
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IPM does however utilize some chemicals, sometimes
quite often.
Biological and physical means of control are
preferred.
Implementing integrated Pest
management
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Utilize VARYING & RESPONESIVE
methods of control
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Most important part of IPM behind scouting, helps
to insure that the overuse of one method of control
does not produce insect resistance
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One reason for the use of buffer zones around Bt crops,
so that resistant insects will breed with non resistant
insects, preventing the development of resistant strains.
Plant science &
biotechnology
Objective: Demonstrate proper
techniques in the micropropagation of
various plant tissue
Selection Material for culture
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Selecting Material
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Only healthy actively growing material should be
selected for use in tissue culture
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Meristimatic tissue from growth points and stem tips
seems to work particularly well in small amounts
Material should also be hardy/ resistant to decay,
easy to manipulate and easily sterilized in solution.
Selection Material for culture
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Sterilizing material
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Prior to use in tissue culture, all plant material
must be sterilized.
The most common means is to:
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Rinse plant material in sterile water for several seconds.
Swirl plant material in a solution of diluted household
bleach for a number of minutes.
Remove plant material from bleach solution (under an
active flowhood) and rinse several times with sterile
water.
Culturing Plant Material
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Steps in the culturing Process
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Prepare the agar media for use to be remelted in it
container if shape has been compromised,
Agar media should only be mixed and exposed to
air under an active flowhood to prevent bacterial
contamination.
Place tissue on the media
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Place tissue firmly on agar media. In most cases,
slightly one edge of the tissue to insure adequate
contact with the agar, and limit movement.
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Tissue may be placed relatively close on agar, as shot
and root development will be compact.
Place tissue on the media
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POLARITY MUST BE MAINTAINED FOR
SHOOTS, SCALES & OTHER CUTTINGS.
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Placing some plant material in media upside down will
prevent the formation of either shoots or roots.
Immediately following tissue placement all containers
should be tightly sealed with the seal wrapped in
perifilm decreased any risk of airborne
contamination.
Transfer of tissue
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After successful development of roots & or shoots,
plantlets must be divided and with redistributed to
new gels, or planted and placed in a controlled
environment for hardening off.
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Most often plant material is encouraged to form
shoots prior to the formation of roots.
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Agar high in cytokinins is used to promote shoot growth.
Agar high in auxins is used to promote shoot root.
Transfer of tissue
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Tissue should be carefully separate using a sharp
sterile scalpel to cut apart shoots on a sterol petri dish
under an active flowhood.