Shared Flashcard Set

Details

HORT 201
Test 4
102
Science
Undergraduate 2
11/28/2012

Additional Science Flashcards

 


 

Cards

Term
Advantages of sexual or seed propagation
Definition
1) produces large numbers in a short period of time
2) can handle large numbers easily
3) produces hybrids
Term
Disadvantages of sexual or seed propagation
Definition
1) some plants produce no viable seeds
2) some seeds are very difficult or slow to germinate
3) causes genetic variability (due to production of hybrids)
Term
totipotency
Definition
the concept that every cell in a plant has the inherent genetic ability to reproduce the entire plant.
Term
Advantages of asexual or vegetative propagation
Definition
1) All off-spring are true-to-type (identical to the parent) and produce a clone .
2) for plants that are hard or impossible to propagate from seeds
3) decrease time to flowering (esp. grafting & budding); by-passes juvenile phase
Term
clone
Definition
a group of plants, cultivar or variety derived from the same parent plant by asexual (vegetative) propagation.
Term
disadvantages of asexual propagation
Definition
1) can only propagate a few from each parent (except tissue culture).
2) requires a lot of labor
Term
tissue culture
Definition
An asexual propagation technique where small pieces of excised tissue or individual cells are placed in sterile in vitro culture containing all the nutrients, carbohydrates and hormones needed for growth. The tissue grows rapidly and can be induced to produce large numbers of new plants. Hormones are used to cause the tissue to grow into callus masses, roots or shoots. Sometimes called micropropagation.
Term
pollination
Definition
deposition of pollen on the stigma of the pistil.
Term
ploidy
Definition
the number of sets of chromosomes present in the nucleus of the cell.
Term
haploid
Definition
1N = 1 of each chromosome
Term
diploid
Definition
2N = 2 of each chromosome
Term
triploid
Definition
3N = 3 of each chromosome
Term
tetraploid
Definition
4N = 4 of each chromosome
Term
gamete
Definition
- a haploid (1N) reproductive cell.
- the male gamete is the sperm cell with its 1N nucleus
- the female gamete is the egg cell with its 1N nucleus.
Term
fertilization
Definition
the union of one male gamete (1N sperm nucleus) and one female gamete (1N egg nucleus) to produce a zygote (2N).
Term
double fertilization
Definition
union of one male gamete (1N) with one female gamete (1N) to produce a zygote (2N), plus the union of one male gamete (1N) with two polar nuclei (1N each) to produce an endosperm (3N); occurs in higher plants only (angiosperms).
Term
apomixis
Definition
development of an embryo without fertilization; hence, it is not true sexual propagation even though it produces a seed.
Term
parthenocarpy
Definition
development of fruit without seeds.
Term
vivipary
Definition
germination of seeds inside the fruit while still attached to the parent plant.
Term
stages of seed germination
Definition
1st Stage
a) imbibition - initial absorption of water to hydrate seed
b) activation of metabolism - increased respiration and protein synthesis

2nd Stage
a) digestion of stored food- for example, starch to sugars in cotyledon or endosperm
b) translocation to embryo- sugars move to embryo for growth

3rd Stage
a) cell division and growth - development of seedling
Term
dry seed dormancy
Definition
caused by: dehydration of the seed
type of dormancy: quiecence
how to overcome: sow in moist environment
Term
Seed Coat Dormancy or Hardseededness
Definition
caused by: hard seed coat impermeable to water and gases
type of dormancy: quiescence
how to overcome: scarification: physical or chemical abrasion of seed coat
Term
Embryo rest dormancy
Definition
caused: low growth promoters and/or high growth inhibitors in embryo
type of dormancy: rest (physiological dormancy)
how to overcome: stratification: cold (35-40 F), moist storage for 4-12 weeks
Term
Double dormancy
Definition
caused by: hard seed coat plus embryo dormancy
type of dormancy: both quiescence and rest
how to overcome: scarification then stratification
Term
chemical inhibitors
Definition
caused by: inhibitors in pericarp (fruit wall) or testa (seed coat)
type of dormancy: correlated inhibition
how to overcome:
1. if fleshy, remove fleshy pericarp (fruit wall) or testa (seed coat)
2. if pericarp or testa is dry, leach in running watery
Term
immature embryo
Definition
caused by: underdeveloped or rudimentary embryo
type of dormancy: developmental dormancy
how to overcome:
1. after ripening: store for 4-6 weeks in ambient conditions
2. warm stratification: warm moist storage
3. embryo culture: excise embryo and put in tissue culture
Term
Light requirement
Definition
caused by: phytochrome in Pr form
type of dormancy: secondary dormancy
how to overcome:
1. expose to any white light
2. expose to red light
3. sow shallow or on surface
Term
cutting
Definition
a plant part that when removed from the parent plant and placed under the proper environmental conditions forms adventitious roots and/or shoots.
Term
antitranspirants
Definition
chemicals that decrease transpiration by forming a film on the leaf surface or by physiologically closing stomata
Term
how to minimize water loss of cuttings
Definition
1) Place cuttings in cool, humid area - for leafless cuttings
2) Spray cuttings with antitranspirants.
3) Place cuttings in a humidity chamber - enclosed chamber with very high humidity.
4) Place cuttings under an intermittent mist system.
Term
Intermittent mist system
Definition
A propagation system that periodically (every 5 to 30 minutes) sprays a fine mist of water on the cuttings to keep the foliage moist and minimize water loss.
Term
intermittent mist systems effective due to
Definition
a) high relative humidity
b) cooler temperature
c) allows use of higher light intensity
d) increases endogenous root promoting substances
e) may decrease disease
Term
leaching
Definition
the loss of nutrients and other compounds from inside leaves and stems. During intermittent mist propagation up to half of some of the nutrients in the leaf can be leached out. This causes the cuttings to be nutrient deficient.
Term
nutrient mist
Definition
addition of dilute fertilizers to the mist; replaces nutrients lost to leaching. Use 2-6 oz. of a 20-20-20 or equivalent soluble fertilizer per 100 gallons of water.
Term
auxin
Definition
- stimulates adventitious root formation on stem cuttings.
- IBA (most commonly used), NAA (frequently used), 2, 4-D (less used).
Term
cytokinin
Definition
-stimulates adventitious shoot formation on leaf or root cuttings.
-kinetin (commonly used), benzyladenine (BA) (commonly used), zeatin (seldom used), pyranylbenzyladenine (PBA) (used in research).
Term
leaf cuttings
Definition
must form both adventitious shoots and roots (except leaf bud).
Term
stem cuttings
Definition
must form adventitious roots
Term
root cuttings
Definition
must form adventitious shoots
Term
chimera
Definition
-a plant or plant part composed of genetically different layers.
-The most common example is a "variegated" plant where different regions or layers of the leaf are yellow or white due to no chlorophyll development, i.e. these are chlorophyll mutants.
Term
L-I
Definition
-epidermis of all organs;
-monocot leaves- contributes to the outermost region of the leaf mesophyll giving rise to a strip along the leaf margin.
-dicot leaves- usually gives rise to only the colorless epidermis, thus cannot be seen; sometimes give rise to small islands of tissue along the margin.
Term
L-I
Definition
-epidermis of all organs;
-monocot leaves- contributes to the outermost region of the leaf mesophyll giving rise to a strip along the leaf margin.
-dicot leaves- usually gives rise to only the colorless epidermis, thus cannot be seen; sometimes give rise to small islands of tissue along the margin.
Term
L-II
Definition
-stem and roots: outer and inner cortex and some of vascular cylinder
-leaves: mesophyll in outer region of leaf
Term
L-III
Definition
-stem and roots: inner cortex, vascular cylinder and pith
-leaves: mesophyll in central region of leaf
Term
layering
Definition
a propagation technique where roots are formed prior to the stem being removed from the parent plant
Term
woody dicots and gemnosperms in layering
Definition
A ring of bark is removed from around the stem. The phloem and cambium are attached to the inside of the bark, so when the bark is removed the phloem is also removed. This leaves the central cylinder of xylem and upward water flow unaffected.
Term
grafting
Definition
the joining of separate plant parts together, such that they form a union and grow as one plant.
Term
scion or cion
Definition
the upper part of the graft that becomes the shoot system of the new plant.
Term
stock, rootstock, or understock
Definition
the lower part of the graft that becomes the root system of the new plant.
Term
budding
Definition
a type of grafting where the scion is just a bud piece or small chip of wood with a bud attached.
Term
reasons for grafting or budding
Definition
1) Plants cannot be propagated by other means, ex. plants in adult phase
2) Decrease time to flowering and fruiting, especially fruit and nut trees
3) Obtain desirable characteristics of rootstock, such as:
a) disease resistance
b) adapted to soils or climate in various regions
c) dwarfing
4) Change variety, topwork mature trees
5) Special forms, usually for ornamental purposes, ex. tree roses
6) Repair damage (inarching, brace graft, bridge graft)
7) Virus indexing, used for diagnosing virus diseases
Term
STAGES OF GRAFT AND BUD UNION FORMATION
Definition
Prerequisite- must match cambium of stock with cambium of scion
1) Callus formation by both stock and scion
2) Intermingling of callus from stock and scion
3) New cambium forms in callus between stock and scion
4) New secondary xylem and phloem from new cambium to connect stock and scion
Term
FACTORS AFFECTING SUCCESS OF GRAFTING AND BUDDING
Definition
1) Plant type - can only graft dicots and gymnosperms; not monocots (lack a cambium)
2) Plant Relationship - within species is most successful
3) Incompatibility - sometimes graft or bud is rejected, even if within species
4) Season and growth state - best when cambium is active, but without leaf growth
5) Environment - must supply proper temperature, humidity, etc.
Term
pruning
Definition
removal of plant parts, branches, shoot tips, buds, roots, etc.
Term
dehorning
Definition
heavy drastic pruning of large limbs; should be avoided at all times; also called pollarding.
Term
thinning out
Definition
removal of branches back to their point of origin.
Used to:
1) decrease density of the canopy
2) encourage other branches to grow and rejuvenate plant
3) redirect growth
Term
heading back
Definition
removal of the terminal portions of a branch.
Used to:
1) increase density of the canopy
2) encourage branching
Term
pinching
Definition
removal of the young, succulent tips of shoots.
Term
hedging
Definition
removal of growth flushes on hedges or shrubs to shape canopy and induce dense growth.
Term
disbudding
Definition
removal of excessive flower buds on flowering pot plants
Term
root prunning
Definition
pruning of roots, usually with a shovel, to prepare plants for transplanting.
Term
objectives of pruning
Definition
1) Health and safety
2) Maintain desired form
3) Dwarfing
4) Invigoration
5) Increase productivity
6) Equalize root/shoot ratio
7) Develop strong branch framework
Term
topiary
Definition
pruning to produce a 3-dimensional design or form.
Term
espalier
Definition
pruning to produce a 2-dimensional design or form.
Term
growth state
Definition
best when inactive or dormant
Term
Susceptibility to winter injury
Definition
or plants easily damaged by winter freezes
● prune after cold of winter.
● remove all winter killed tissue.
you may need to allow some spring growth to tell if tissue is dead or not.
Term
spring flowering plants
Definition
❍flower on last years growth (2 year old wood); i.e. flower buds present since last summer or fall.
❍therefore, prune right after flowering in spring and before new buds form.
Term
summer or fall flowering plants
Definition
❍flower on current years growth (1 year old wood); i.e. flower buds form on new growth of current year.
❍therefore, prune fall, winter or early spring, but best to prune after cold of winter and before new growth starts
in spring.
Term
transplanting
Definition
pruning should be to equalize root/shoot ratio, thus, decrease transplanting shock.
Term
transplanting
Definition
pruning should be to equalize root/shoot ratio, thus, decrease transplanting shock.
Term
to equalize root/shoot ratio
Definition
a) thin-out immediately after or at the time of transplanting
b) root prune before transplanting (months to years).
Term
chemical pinching agents
Definition
Chemicals that selectively kill or disrupt shoot tips to remove apical dominance.
1) Atrinal
2) Off-Shoot-0
3) Maleic hydrazide
4) Emgard 2007
Term
pest
Definition
any undesirable organism that is injurious to plants, either directly (ex. insects, or fungi) or indirectly (ex. weeds).
Term
THREE PREREQUISITES OF PEST DAMAGE OR INFECTION
Definition
1) plant susceptible
2) pest present
3) proper environment
Term
plant resistance
Definition
a) Genetic Resistance - this is the "ideal" method of pest damage control
Term
proper environment
Definition
a) Favorable for plant
b) Unfavorable for pest
Term
eliminate pest
Definition
a)Quarantine - usually governmentally imposed
b) Sanitation - wash pots and tools, hoses off ground, propagate clean plants, etc.
c) Physical Control - bug traps, screens, sticky boards, etc.
d) Biological Control - the use of one organism to control another organism.
1) Bacillus thuringiensis - a bacterium that controls caterpillars
2) grass carp (or white amour) - a fish that eats submerged aquatic weeds
3) predaceous mites - eat other mites and small insects
4) parasitic wasps - lay eggs inside other insects
5) Trichoderma - a fungus that controls other fungi
6) allelopathy - secretion of chemicals by one plant that retards the growth of surrounding plants
Term
pesticides
Definition
chemicals used to control pests; ex. fungicide, bactericide, insecticide, miticide, herbicide
Term
modes of action
Definition
1) Contact Pesticide (insects and weeds)
2) Systemic Pesticide (insects and weeds)
3) Stomach Poison (insects only)
Term
integrated pest management (IPM)
Definition
the use of all strategies of pest damage control (resistance, cultural, biological, environmental and chemical) to minimize the economic impact of pests.
Term
class insecta
Definition
● 6 legs
● 3 body regions; head, thorax, abdomen
● 1 pair antenna
● wings (may be reduced or vestigial)
Term
order homoptera
Definition
very common insect pests on horticultural crops
Characterized by:
- sucking mouth parts that extract phloem sap
- secretion of honey dew - a sugary liquid secreted by Homoptera
- presence of sooty mold - a black to brown mold that grows on honey dew on the leaf surface does not infect plant)
- includes aphids, mealybugs, scale and whitefly listed below
Term
aphid
Definition
sucking mouth parts; small soft bodies, green, brown or black; around growing point; ants may "farm"
Term
mealybug
Definition
sucking mouth parts; soft bodies covered with cottony wax filaments
Term
scale
Definition
sucking mouth parts; covered by a hard shell
Term
whitefly
Definition
immature with sucking mouth parts; as translucent ovals under the leaf; adults as small white flies
Term
thrips
Definition
rasping-sucking mouth parts; cause lesions on young leaves and flower petals
Term
leaf miner
Definition
bore meandering tunnels through leaves
Term
caterpillar
Definition
have chewing mouth parts and eat whole tissues; leave droppings
Term
grub and borer
Definition
larva of beetles; feed on roots, bore into wood of stems
Term
beetle or grasshopper
Definition
have chewing mouth parts and eat whole tissues
Term
weevil
Definition
feed mainly on stored grain.
Term
class arachnida
Definition
-spiders, scorpions, mites, ticks
● 8 legs
● 2 body regions; cephalothorax, abdomen
● no antenna or wings
Term
spider mite, red spider, or spotted mite
Definition
very small; cause a fine yellow speckling on leaves where they feed, and form webs when severe
Term
root-knot nematode
Definition
bore into roots and cause the root to have a swollen, knotted appearance.
Term
pathogens
Definition
microorganisms that invade, infect and cause damage to another living organism.
Term
fungi
Definition
long, multicellular filamentous microorganisms composed of membrane-bounded cells surrounded by cell walls
-causes necrotic spots
- moldy or powdery appearance on leaves
Term
bacteria
Definition
usually rod shaped, single-celled (may form filaments) microorganisms composed of a membrane-bounded cell surrounded by a cell wall.
- causes soft, mushy, odorous regions on leaves or stems, "soft rot"
- causes circular, ringed lesions
Term
virus
Definition
rod-shaped, spherical or crystalline-shaped microorganisms composed of strands of nucleic acids surrounded by a protein coat.
● causes yellow mosaic or mottling of leaves
Term
mycoplasma and spiroplasma
Definition
pleomorphic (means takes on shape of the organism it is in) microorganisms with membrane- bounded cells, but without cell walls.
Term
rickettsia-like organisms
Definition
bacteria-like organisms that can only live inside living cells
Term
weeds cause damage by:
Definition
1) competition
2) allelopathy
3) expense
4) disease and insect hosts
5) contaminate foods
6) poisonous
7) aesthetically undesirable
8) parasite, ex. dodder, mistletoe
Supporting users have an ad free experience!