Exam 3 HS 201

Plant growth

increase in size/mass ( quantitative)

Plant development

differentiation of cells and tissues; does not have to increase in size or weight ( qualitative)

Cellulose in plants

principle polysaccharide in cell walls, provides strength and rigidity, compromises 33% of all plant matter, more in some plants ( 90% cotton, 50% wood)

Annual production

1.5 trillion tons

Indigestible by humans

we lack the proper enzymes to digest it ( fiber)

Ruminants and termites have bacteria in their gut to help digest cellulose

true

Specialized groups of cells performing a specific function

dermal, ground, vascular

Meristems

produce cells that quickly differentiate into permanent tissue

Primary meristems

found in shoot and root tips, Called apical meristem

Responsible for primary growth in length and height 

Primary growth systems Xylem

transports water/nutrients up in roots stems and leaves

Primary growth systems phloem

transports sugar up and down in roots stems and leaves

Primary growth systems vascular bundle

group of conducting tissues ( xylem, phloem, cambium)

Secondary meristems

responsible for growth in girth ( width) Compromised of two main lateral side meristems

1. Vascular cambium

secondary xylem(inward) and secondary phloem ( outward)

2. Corm cambium

periderm ( outer bark)

Secondary xylem

wood

Heartwood

dead nonfunctioning filled w dead cells and preservative compounds

Sapwood

mostly alive functioning ( conductive)

Growth rings

annual rings, layers of wood produced by trees during one year of growth

Dendrochronology

science/tech of dating events and environmental patterns by studying growth rings

How Dendrochronology

1. Study cross section of cut tree

2. Take tree cores from standing tree

Petrified wood

wood turned to stone by permineralization

Petrified forest

black hills south dakorta, located on mountain top in piedmont SD ( rapid city), species

Secondary phloem

inner bark, Produced outwardly by the vascular cambium and transports food from leaves to rest of plant

What would happen if bark all the phloem were removed from tree ( winter 1999)

bad nutrients

Trees grow in height from the tip ( top), not from the base ( soil line)

true

Inosculation

natural grafting in which the branches of the two plants grow together ( xylem and phloem)

Oldest tree

Pinus Longaeva

Pinus Longaeva

bristlecone pine, white mountains of SW U.S, oldest living non

Donald Currey

geology grad student was sampling bristlecone pine for climatic date, discovered WPN

Sequoia Sempervirens

cali/coastal redwood, only member of genus, 800 years, tallest trees on earth ( hyperion), 381’ high and 27’ wide at DBH, only 5% of forests remain, prior to 1850’s it was common tree

Sequoiadendron gigateum

giant sequoia, only member of genus, 2200 years, largest tree by volume ( 275’ tall and 36’ in diameter, 2000 tons, 52500 cubic feet, adds 40 cubic feet annually, 1000 lb per year

Pinus Coulteri

coulter pine aka widow maker, coastal Mtns of southern CA, largest conifer cone 8

Bark

wrinkly, warty interlacing ridges, lenticels, prickly, thorny

Bark

outermost protective layer enveloping the trunk, branches, and roots of woody plants

Bark formation

vascular cadmium produces wood on inside and inner bark on outside

Cork cambium produces

outer bark

Bark function

Protection from mechanical injury, Protection from disease and inscest, Dumping ground for plant waste, Transports water and sugar through the tree, Insulation from fire

How much bark is on a tree

amount varies by tree species, on average about 10% of a tree is bark 5

Alate

corky, winged, bark ( euonymous alatus)

Prickles

sharp outgrowth of the epidermis ( leaves/stems)

Uses of bark

huge impact on human society

1. Cork

quercus suber, portugal has 2 mil acres in cultivation 50% of world supply, first harvest 25 years, 9

2. Spices

cinnamon

3. Phytotherapy

salix alba

4. Aestetic

pinus bungeana

5. Potting soil

waste product of timber industry

Light duration

number of continuous hours of light in a 24 hour period

Light quantity

number of light particles ( photons) of different wavelengths ( colors) that are capable of performing photosynthesis

Light quality

spectral distribution of light ( number of photons) emitted from a light source

Effects

photosynthesis, pigment, seed germination, fall color, growth, size, flowering, fruiting

Pigments

carotene ( orange), xanthophyll ( yellow), chlorophyll ( green), anthocyanin ( red)

Phototropism

plant response to light

Auxin

plant hormone produced in stem tip, aides in organ development and cell elongation, concentrated in shaded regions of stem

Light compensation point

rate of photosynthesis equals rate of respiration ( energy burned to maintain life)

Light saturation point

amount of light, beyond which no added benefit( growth) is obtained

Site selection is key

how much sun exposure do you have, select plants that can survive in that level of life

Full sun( high light) area and plants that require full sun

growth occurs

Low light area and plant that requires high light

no growth, slow death

Shade leaves

larger, thinner, greener, lower light compensation point, more efficient photosynthetic apparatus

Acclimatization

slowly change environment

Hardening off

before planting outside, vegetable transplants, houseplants

Etiolation

plant grown in partial or full absence of light

Blanching

growing tech to exclude light

Distinct odor in urine from asparagus

sulphureous compounds

Fall color influenced by genetics, environment

true

Deciduous plants

decreasing day length, temperature

Decreasing temp and photoperiod stimulates the formation of the leaf abscission layer, flow of water and nutrients slows, production and flow of sugars slows

true

Chlorophyll synthesis slows down, leaf fades in green coloration, yellow and orange pigments show through, always present just hidden

true

Development of red pigmentation is a function of daily climatic conditions and sugar accumulation in leaves, right combo leaves to red pigment

red pigment

Red

warm dry sunny days, cool dry nights, sugar pool build up, night temp <45

Fall climate influences sugar acclimation, location influences climate, microclimate matters

true

Plant growth response as influenced by the duration of light and darkness in 24 hour day, 1920 garner and allard, flowering, seed germination, rooting, abscission

true

3 categories of angiosperms

1. Long day plants plants that are stimulated to initiate flowering when the day length is longer ( potato)

2. Short day plants- plants that are stimulated to initiate flowering when day length is less

3. Day neutral plants simply flower at some stage of growth with regard to the length of day or night

Photosynthesis

100 billion tons of sugar produced by plants annually, 94% of dry matter in plants from photosynthesis ( 6% from soil)

Only 1% of light that hits a leaf is used for photosynthesis, only 1% of water absorbed by plants is used in photosynthesis

true

6CO2+ 6H2O= C6H12O6+6O2

photosynthesis formula

Plant propagation

use of seeds or vegetative plant parts to produce more plants

Sexual

seeds, less tech, easy shipping, genetic diversity, new colors texture hybrids

Asexual

vegetative, leaf, stem, root, no reproductive pressure, bigger plants faster, flowering faster, clones, mutation preservation

4 pillars environment

air, water, light, media

Soil/substrate/media

water retention, drainage, sterility ( no pests or diseases)

Seed sowing environment

water

Air and media

warm to seeds optimal temp, avoid too much moisture, low nutrient need

Sowing depth

1.5 * diameter or seed

Seed selection and info

seed packets provide culture needs, grow time varies by species and cultivar, check sow depth

Seed conditioning

watch for tropisms, tropos

Asexual prop

vegetative parts

Categories

cutting, grafting, layering, division, micropropagation

Auxin

naturally occurring

1. Stem cuttings

Types- herbaceous- any time

Softwood- new growth

Semi-hardwood- seasonal growth

Hardwood- old/dormant growth

Node+bud, wound base to promote rooting

true

Intentional black out stock plant

etiolated

2. Totopotency

cells ability to differentiate into new tissues and become a complete, fully functioning plant

Limited species can grow from leaf cuttings

3. Leaf cuttings

regenerative growth forms both roots and shoots out of leaf vein, Media contact and leaf orientation are important, Plants can be gently separated from original leaf,

4. Roots cuttings

specialized propagation method of some species, Carbohydrates stored in roots of dormant plants

Cutting environment- water and air and media

High humidity, avoid dry-out, reduce after baby roots form

Grafting

scion- top protion develops shoots

Rootstock- bottom portion develops roots

Cambium tissue connection

Same or closely related specifieds

Selected for mutual benefits

disease resistance, cold hardiness, structure and form, pollination tech, wow factor

Rootstock

poncirus trifoliata “monstrosa or flying dragon”

4-6’, tart fruit 2” and seedy

Scion

citrus sinensis “washington navel”

10-12”, sweet fruit, 4”, seedless