Revision slides Flashcards
temperature directly affects ( the rate of these processes increase with an increase in temperature
photosynthesis
respiration
transpiration
absorption
low temperature results in x GROWTH
Poor
high temperature causes increased respiration sometimes above the rate of photosynthesis
for growth photosynthesis must be greater than respiration
what plants stop producing vegetative growth and Strat producing flowers and seeds in high temperatures
bolt
no light- no chlorophyll
etiolation very long straggly
low intensity light red wavelenghts
long spindly growth
high intensity light (UV wavelengths)
plant dwarfing
Photosynthetically active radiation (PAR)
400-700NM
Phytochromes
photoperiodism
if plants become too dense what stops?
Photosynthesis
<15% O2 reproduction is
<2.5% O2 reproduction
<0% anaerobic respiration takes
reduced
stops
place
anaerobic conditions in flooded soil can lead to
ethanol toxicity
under drought conditions plants close their
stomata
central atom of chlorophyll
magnesium
Macro nutrients
N P K Mg S Ca
monocots
1 leaf
dicots
2 leaf
function of roots
- water uptake
- aching
- binding the soil
- nutrient uptake
inhibition
seeds absorb moisture and swell until the seed coat bursts
annual weeds
1.fat hen
annual nettle
charlock
red dead nettle
red shank
6. cleavers
biennal weeds
ragwort (pigs, horses, goats, deer, chicken )
wild carrot
Perennial
docks
bracken
couchgrass
bishop weed
ephemeral
hairy bittercress
groundsel
Fungal disease
ash dieback
bacterial disease cherry laurel (X%)
shot hole disease 30 %
viral disease
Potato virus (5 types)
leaf modifications
1.poison
2.spine
3.reduced leaf
4.leaf tendril
5.succulence
6.storage lead (bulb )
7. carnivory
8. petal
9. sepal
stem modifications
1.thorns
2. succulent stems
3. corm gladiolus
4. stem tendril
5. stem tubber potatoe
6. stolon
root modifications
storage root
root tuber
prop root
aerial root
epiphyte
pneumatophore
sexual reproduction
produces offspring by the fusion of egg and sperm resulting in genetically different parents and each other
asexual reproduction
vegetative reproduction produces offspring without the fusion of an egg and sperm. offspring genetical identical
sexual reproduction =
seeds
asexual reproduction
fragmentation
tubers
bulbs
cuttings
grafting
stolons, runners
potatoes
onions daffodils
stem, leaf , root
fruit trees
certified seed
seed that is handled as so to satisforily maintain GENETIC IDENTITY and PURITY and that has been approved and certified by the certifying agency
Plant breading goals
- yield
- quality traits
- havestilitby
- persistance
Growth scale
Zadoks decimal
Climate change
long term shifts in temperature and weather patterns since the 1800s human activities have been the main driver. (burning fossil fuels which produced heat trapping GHG)
GHG
Carbon dioxide
methane 4
nitrous oxide
fluorinated gases
climate action plan aims to reduced GHG by X%
51% 2030
> X% of farming GHG emissions directly linked to animals and the manture they create
80%
X of emissions is blamed on fertilisers
1/8
climate action plan requires agriculture to reduced GHG by X%
25%
farmers are rewarded for what they produce rather than how they produce it
10th consecutive year no. dairy cows rose
largest single stem tree volume and mass
giant sequoia
tallest tree in the world
coastal redwood 116m
oldest living tree
Great Basin Bristlecone Pine (Pinus longaeva)
>5,000 years old
if moisture is a limiting factor
fertiliser is not used efficiently
herbicides are not taken up efficiently
stages of germinating seeds
- imbibition
radicle pushes through the seed coat
primary root begins to develop
primary leaves begin to unfold
true leave completely emerge and the cotyledons eventually fall off
atmospheric Factors affecting water absorption in plants
temperature
relative humidify
vapur pressure deficit (VPD)
Wind speed
Biological factors affecting water absorption in plants
plant species
root length
root sytem
plant health
growth rate
Plant oomycete disease
water molds”, are a group of several hundred organisms that include some of the most devastating plant pathogens. The diseases they cause include seedling blights, damping-off, root rots, foliar blights and downy mildews.
Fluorinated gases how much larger effect than CO2
23,000 greater
agri is responsible for XX% of national NH3 emissions
99%
flowering plants
angiosperms (vascular)
conifers
gymnosperms (vasculare )
ferns and fern allies ( pteridophytes) ( vascular)
pteridophytes) ( vascular)
disperse spores
mosses and liverworts
bryophytes ( non vascular)
Poaceae
grass family 798
most important family to humans
rice, maize, wheat, barley
weeds
meadow grass
wild oats
couch, scutch
Asteraceae
Daisy family
1911 generas
no agri importance but weeds are important
ragwort,
knapweed
coltsfoot
creeping thistle
dandelion
Solanaceae crops
nightshade family
115 plant genera
many members poisonous
weeds
black nightshade
Apiaceae
celery/parsley/ carrots
418 plant genera
weeds
wild carrot
hogweed
ground elder, bishopweed
Rosaceae
Cultivated fruits- apples, pears, peaches ornamental plants for gardens
104 plant genera
WEEDS
Silverweed
creeping cinquefoil
meadowsweet
brambles
Rosaceae
Cultivated fruits- apples, pears, peaches ornamental plants for gardens
104 plant genera
WEEDS
Silverweed
creeping cinquefoil
meadowsweet
brambles
Fabaceae
legume family pea/bean fam
946
importance for fixing nitrogen gas from the air
irregular flower with 5 petals
WEED
hairy vetch
gorse
Amaranthaceae
goosefoot family
178 plant genera
tiny greenish flowers
have sepals but NO petals
flowers densely clustered on spikes
Crops
quinoa
spinach
sugar and fodder beets
WEED
Fat hen/ goosefoot
Brassicaceae
cabbage family
372 plant genera
4 petals in a cross
Crops
oilseed rape
leafy forage crop
Weeds
charlock (annual )
shepherds purse (annual)
7 classifications
kingdom
phylum
class
order
family
genus
species
king Philip comes over for good spaghetti
leaf blade
grows from the base of the blade
sheath
lower part of the leaf that hugs the stem
nodes
elbows along the culm add strength
allow change in direction of growth
male parts
stamens
—– anther
——filament
female parts
stigma
—–style
—– ovary
Rhixomatous
A rhizome (also known as a creeping rootstalk or rootstock) is a type of plant stem that grows horizontally underground or across the soil surface. Its main purpose is to store carbohydrates and proteins so the rhizomatous plant can survive between growing seasons.
Stoloniferous
A horizontal stem that is located above the ground and usually produces adventitious roots and vertical stems at the nodes. Stoloniferous refers to a plant that bears stolons.
Cespitose/tufted
forming mats; growing in dense tufts.
cultural methods of weed control
crop rotation
alternating winter and spring crops
burying your problem
chemical
when to spray weeds
young
healthy
growing actively
Von Liebig’s law of minimum
plant growth is limited by the scarcest resource
global N fertilser use
100 million tonnes
N deposition
via precipitation
nitrification
oxidation of ammonium to nitrite and then nitrate
Denitrification
closes the loop in the N cycle
Redox reaction- oxidation- nitrate is electron acceptor
incomplete denitrification N20 potent GHG
Where do the greatest losses from applied N occur
well drained soils
how do bacteria gain their food
make their own
scanvengers
host pathogens
Pseudomonas syringe
type of bacteria that can infect a wide range of species
it exits as over 50 different path ovars
possible lifecycle of bacteria
bacteria overwinters in dead plant material but doesn’t survive long in water or soil
rain splash speeds bacteria from infected leaves and debris
bacteria uses natural opening or injury to infect
entering the stomatal cell
diseases symptoms as bacteria colonise
virus do they have all the characteristics of life
no
Virus
sub microscopic entity consisting of single nucleic acid (RNA,DNA) surrounded by a protein coat
only capable of replication within the living cells of plants animals and bacteria
reproduce using the host machinery
internal factors of plant regulation of growth
Photosynthesis
Photoperiod
transpiration
respiration
limiting factors of growth for a plant
light
CO2
O2
Temperature
Water
Minerals
What do plants that respond to daylight contain
Phytochrome C
What do plants that respond to daylight contain
Phytochrome C
O2 is required for
aerobic respiration, cell repair, reproduction, growth
plant enzymes operate best at
25 Degrees
too low membranes not fluid affecting transporters
too high membranes disintegrate and plant dies
Epidermis
outermost layer of cells like the skin of the root
cortex (ground tissue)
tissue inside the epidermis that stores starch and other substances made out of parenchyma tissue
vasculare tissues
Vascular tissue is comprised of the xylem and the phloem, the main transport systems of plants. They typically occur together in vascular bundles in all plant organs, traversing roots, stems, and leaves. Xylem is responsible for the transport of water and dissolved ions from the roots upwards through the plant.
Cortex
storage and defense
endodermis
selective mineral uptake
pericycle
lateral root formation
casparian strip
band around the endodermis
external root anatomy
- root cap
- region of cell division
- region of elongation
- region of differentiation or maturation
ground meristem
the basic primary tissue of the growing tip of a stem/root excluding the epidermis and vascular bundles which gives rise to the cortex, rays and piths.
apical meristem
found at the top of the root where new cells develop. it is covered by the root cap which protects it from damage passing through the coarse soil particles.
Protoderm-
ground meristem-
procambium
forms the epidermis
forms the ground tissue/cortex
forms the primary phloem and xylem ( vascular bundle)
Root cap
thimble shaped mass of parenchyma cells at the tip of each root
secrets mucigel ( provides and environment for bacteria and fungi which live in the rhizosphere)
Meristem
pool of cell capable of dividing stem cells
Stomata
dermal tissue complex from guard subsidiary cells that form openings
function gas exchange and water loss
plasmodesmata
thin strings of cytoplasm that pass through between plant cells that allow for intercellular cell communication
Fruiting bodies
modified hyphen that make asexual (mitotic) spores
Basida
sporangia
ascus
