Test 2 Flashcards
Annual-
Completes life cycle in one growing season
Germination– Vegitative Growth–Reproductive growth–Death
Biennial
Requires two growing seasons to complete lifecycle
Seed- Veg Growth one– Dormancy– Veg Growth 2– Reproductive Growth– Dead
Perennial-
Lives for more than two years(woody or herbaceous)
Seed– Veg Growth–Reproductive– Dormancy — Death but can go from dormant to Veg again.
Monocarp–
can live for many years but once it flowers it dies.
Germination– growth–dormancy–flowering– death
with a loop on growth and dormancy
What are the four main stages of maturation in plants?
Germination
Juvenility
Maturity
Senescence
Three main parts of a seed-
Embryo
Seed Coat( Testa)
Stored Energy
Describe the beginning and end of Germination-
Starts when seed absorbs water, Ends when the radicle emerges.
When does establishment begin and end-
Time from germination until seedling is independent and photosynthesizing
Environmental Requirements of Germination-
Adequate Moisture
Favorable Temperature (70-80)
Oxygen
Light
Radicle-
Hypocotyl-
Epicotyl-
Growing embryonic Root
Seedling stem between radicle and cotyledons
Seedling stem between cotyledons and first leaves
Describe the difference between Epigeal and hypogeal emergence-
(Epi- above,Hypo-BELOW) in epigeal the cotyledons emerge above the soil surface and the hypocotyl elongates.
In hypogeal the cotyledons stay below the surface and the hypocotyl does not elongate. only the Epicotly emerges. (All grasses)
In epigeal emergence in dicots what emerges from the soil first?
In Hypogeal emergence in dicots what emerges from the soil first?
- The hypocotyl emerges first.
2. The Epicotly Emerges
In hypogeal emergence in monocots what part of the seedling emerges first?
The coleorhiza
What does the juvenile stage of growth begin and end?
What are the four traits of Juvenility?
from germination and emergence to reproduction
Leaf form- different than mature
Growth Form- whiplike verticle shoots
Thorns
Leaf Retention-hold leaves during winter
Flower Induction-
Flower initiation-
Flower Development-
Initial chemical reaction that begins flowering(invisible)
Vegetative meristems change to flower meristems(microscope)
Visible development of flowers from bud to pollination
What four factors can induce the formation of flowers-
Self-induction(maturity)
Photo-induction(light)
Thermal Induction(vernilization req.)
Other-Factors (stress from drought or crowding) (light intensity)
What is photoperiodism-
short day-
Long day-
the response of a plant to the changes in day length
flower when light period is less than critical photo period (longer dark period)
flower when light period is more than critical photo-period (shorter dark period)
What is a phytochromes-
type of plant pigment that is colored blue. It is a light sensitive pigment. They control the ratio of Pred and Pfar red, and cause flowering
How are Pr and Pfr involved in flower induction-
Depending on the ratios they will cause flower induction
Ratio of Pr to Pfr increases SDP will flower
Pfr to Pr LDP will flower
Self Pollination -
Cross Pollination-
Pollen from the same plant fertilizes egg cells or genetically identical plant.
Pollen from genetically different plant fertilizes cells.
What is Parthenocarpy-
the growth of a fruit without fertilization, or after abortion of embryo, can be caused by growth regulation chemicals or specific environmental conditions.
Describe the process of Fruit Ripening.
What hormone is involved?
Sugars move from fruit to leaves, when fruit reaches full size ripening begins. ethylene gas is produced.
Fruit softens when pectic substances breakdown which strengthens cell walls and cements cells together,
color changes occur from breakdown of chlorophyll.
What is senescence? What changes in metabolism accompany senescence?
the aging and death of a plant or any of its parts.
Changes in metabolism include: Increased Respiration
Decreased photosynthesis
Breakdown of larger molecules into smaller ones
What is abscission-
in leaves where does abscission layer develop?
dropping of leaves, fruits, flowers or other plant parts.
where the petiole connects to the stem.
Dormancy-
When are plants dormant-
stage of development where growth slows or stops
occurs during periods not suitable for plant growth
winter dormancy- in cold areas
dryseason- in distinct wet and dry seasons
Why do needle shape leaves help evergreen trees survive the cold temperatures of winter?
they are adapted to minimize water loss due to smaller surface area during times when plants cant get water from frozen soil.
Three ways of breaking dormancy in seeds-
Vernilization- cold treatment
Stratification-storing moist seeds at temperatures near freezing for one or more months
Heat
Scarification- injuring the seed coat enough to allow water absorption and germination
What are plant horomones?
5 main groups?
natural substances produced by plants to control plant activities.
Auxins, Cytokinins, Gibberellians, Ethylene, Abscisic Acid.
Auxins-
Cause apical dominance, weed control
Cytokinins-
Promote cell division and tissue differentiation
Gibberellians
cell division and elongation , enzyme secretion
Ethylene-
Promotes fruit ripening
flower initiation
Abscisic Acid-
growth inhibitor, seed dormancy, stomotal closure
What are plant growth regulators-
3 ways synthetic growth retardants can be used in horticultural crops
influence the plant growth and development, can be hormones or non natural chemicals.
- florist crops to reduce growth
- hedges and lawns to slow growth
- Used to keep bedding plants compact.
- Improve color,
Climate-
Microclimate-
patterns of meteorological variation that develop over a large area over many years. Lat/long and season, mountians, oceans, etc.
weather conditions around a plant part, plant, or group of plants. buildings,ponds, land depression.
Five elements that make up climate-
Temperature Wind Precipitation Humidity Light
Warm Season-
Cool Season-
80-95 Bermuda, Zoysia, Bananna
60-75 Tall Fescue, Ky Bluegrass, Carrot
How are US Hardiness zones defined?
Martin is in?
by expected minimum temperatures, 7a
What is chilling injury?
low temp damage that occurs above freezing (32-42)
What is freezing injury?
low temp damage below freezing casues ice to form in plant tissues, less than 32
What happens to rate of photosynthesis when temps are to hot?
they decrease
how can the plant cool itself-
Transpiration
5 ways we can help a plant cool itself-
Artificial shade Evaporative cooling cooling systems fans Mulching
How are the heat zones on the American Horticultural Society heat-zone map defined?
based on the average number of days with temps over 86 degrees F
How does snow help with survival areas in cold winters?
it covers low plants and can provide water
What forms of precipitation can injure plants?
Sleet, Hail, and freezing rain.
What happens within plants when they are under moisture stress?
loss of turgor slows cell growth
reduced protein synthesis
Reduced photosynthesis
Leaf abscission
How can a plant postpone drought?
How can they tolerate drought?
Deep roots, Hydraulic lift, stored water in vacuoles.
stomotal closure, Osmotic adjustment, Physiological roles(C4 plants)
How can flooded or saturated soils stress plants-
two ways plants can tolerate flooding-
Reduces amount of O2 in soil limiting respiration,
soil microorganisms change in ways that produce harmful by-products to plant roots.
shallow roots, Aerenchyma(small pockets of reserve O2)
Two reasons why dew is important-
can be a factor in spread of disease in turf,
can be an important water source for plants that absorb water through leaves.
Relative Humidity-
whats optimum?
Amount of moisture in the air relative to the amount it could hold at the same temperature is completely saturated.
40-80% optimum
As moisture levels in the air change what happens to water loss in plants?
as moisture levels go up water loss does down
as they go down, water loss goes up
optimum temp and humidity for indoor plants?
60-80 degrees F
50-90% humidity
Full sun-
Partial Shade-
Full Shade-
at least 6 hours of sun per day
receive direct sun for 1/3 to 1/2 of the day.
areas where direct sunlight is rare 1 hour or less
Two ways plants deal with low light?
stack chlorophyll at surface of leaf to maximize absorption
change leaf position on tree (more perpendicular)
How do plants deal with to much light?
reflective modifications- leaf hairs, waxy surface,
light avoiding leaf movements
light absorbing pigments other than chlorophyll
How can wind influence plant growth-
ocean winds- salt spray can limit plant growth near ocean
hot desert- increase rate of moisture loss
subzero winds in cold northern areas damage evergreens by removing moisture from foliage.
Why is it important to consider micro climates?
areas can have more or less wind, shade, moisture, or heat.
Propagation-
Sexual Propagation-
plant reproduction by sexual or asexual methods
propagation by seeds
What factors determine how plant will be propagated by seed or vegetatively?
ease of seed germination
number of plants to be grown
importance of trait preservance
need to produce disease free offspring
What are hybrids? Why are hybrids more vigorous than other plants?
offspring that result from cross-pollination. Usually more vigorous due to hybrid vigor. Seed saved from hybrids may not possess parents traits.
Under what conditions should seed be stored?
in a sealed container in the fridge.
Describe a germination test-
place known quantity of seeds in optimum growth conditions, after no. of days, determine the number of germinated seed counted and determine the % germination.
official test= 4 repetitions of 100 seeds.
What test can be conducted to test the viability of seed?
a Triphyenalteterazolium test
Seed dormancy-
4 mechanisms-
physiological or pyhsical mechanism by which seeds fail to germinate under favorable conditions- survival strategy.
physiological maturity
impermeable seed coats
biochemical blockers
Termperature/ light requirements
Name three ways to break physiological dormancy.
rinsing/leaching
Temperature stimulation (stratification/vernilization)
Light Treatment
How can you break dormancy caused by impermeable seed coats?
Scarification- acid or rough treatment
Define direct and indirect seeding.
sowing seed outdoors directly into field
seedds are started indoors and transplanted
What is a cold frame? What temperatures are usually found in cold frames?
55-60 degrees
an intermediate site where the plant can be exposed to cooler temperature before being completely exposed to the elements.
What are bedding plants? What types of plants are usually sold as bedding plants?
a commercial classification of plants usually sold in the spring and in some climates in the fall.
annual seedlings, vegetables, or perennials
what are plugs-
flats composed of 800-1000 small cells each of which holds on plant(plug) most common way to produce commercial plants.
What is transplant Shock-
shock to seedling when transplanting, due to extreme change in temperature, drying, wind, pests.
What is vegetative or asexual propagation? Name three advantages of using vegetative propagation.
no meiosis or fertilization, no genetic recombination.
plants are genetically identical to parent plant.
-useful for plants that cannot reproduce by seed.
short time from propagation to mature plant
plants are genetically identical to parent.
Name five stem structures that can be used in vegetative propagation.
bulbs/cormbs tubers stem sections/cuttings rhizomes stolons
What are cuttings? What are stock plants?
plant material that is going to be grown from part of the stock plant.
plant with desired traits to replicate
What is ‘rooting hormone’ composed of?
auxins, cytokinis, and algaecide/ fungicide
What is the general procedure for rooting hardwood or semi-hardwood stem cuttings?
What are the differences among hardwood, semi-hardwood, softwood, and herbaceous cuttings?
taken in summer, 3-6’’ long, partially matured new growth. place in premoisened plastic bag, store in refrigerator. in spring place 1-2’’ of stem in media in covered 70-80 degree environment. wait for rooting. 6 weeks.
Hardwood- matured wood from current season growth
Semihard wood- Partually matured new growth of the season
Softwood- new succulent growth
herbaceous- from herbaceous plants
What is the difference between a stem tip cutting and a leaf bud cutting?
What is a stem section or cane cutting? (be able to identify these three types of cutting from a diagram of a plant).
top 2-4 in. of growing stem
leaf bud- taken after stem section has been used.( stem section, leaf, axulary bud)
Short peices of stem, must contain 2-3 nodes, lay horizontally.
What parts of a leaf can be used for cuttings in some species?
Name a plant species in which it is easy to make rooted cuttings from leaves.
Single leaf, some with petiole. African violet
Layering-
While on the plant a long hanging branch is brought in contact with the soil, covered and allowed to root at the node.
Describe the step by step procedure for air layering.
cut away cambium from stem,
cover section with damp peat moss and plastic
secure both ends to seal in moisture
if in direct sun cover with foil
when several roots 2-3’’ long form, cut from parent plant.
What is division? What stem structures can be used for making divisions?
separating crowns or modified stems to increase numbers
Give an example of a plant that can be propagated via bulbs.
Name a species that can be propagated via corms.
Name a species propagated via tubers.
tulips
gladiolus
potato
What are rhizomes and stolons (runners)? Name a species propagated by dividing rhizomes and a species propagated via stolons.
below ground stems
above ground stems
bermudagrass
spider plant- stolons
What are suckers and offsets?
Young shoots that grow from roots and stems of mature plants
Define stem grafting. What is the scion and what is the rootstock?
What is the benefit to grafting one plant onto another?
Name two other uses for grafting.
uniting two genetically different plants so that they heal together to make one plant.
plant A= bud(top) system (scion)
Plant B= Rootstock
Repair girdled trees
Make unusual shapes
Why must the cambium of the scion and rootstock be aligned?
they are still actively growing parts of the plant.
•Describe whip grafting, cleft (or wedge) grafting, and bud grafting. Use a diagram if necessary to explain each.
whip- equal diameter and cut at an angle held by rubber strip
cleft/wedge grafting- v shape
bud- cut a tshape in tree, insert into slot (least risky)
What is tissue culture? What parts of plants are propagated via tissue culture?
propagation of plants from nearly microscopic plant parts.
Meristems, cells , anther/pollen/ ovaries.
Name two horticultural crops in which GMO varieties are available.
Corn
Apples
