Grapevine Physiology and Structure Flashcards
What do meristem cells do?
Perform the specialized function of growth by the creation of new cells through cell division.
What is the apical meristem?
a tiny growing point within the folding leaves at the tip of the expanding shoot.
What are the additional growing points at the base of each leaf?
Buds
What are two specialized meristems in the vine?
Vascular cambium and cork cambium, which are responsible for radial growth of woody parts of the vine.
Does the soot tip have a meristem?
Yes
What produces new xylem and phloem tissue every year?
Vascular cambium
What does the phloem transport and where is located?
sugar; outside
What does the xylem transport and where is located?
water; inside
Where are buds located?
at the base of each leaf?
How are the leaves arranged on a vine?
alternating
Where are the clusters on a shoot?
At the third or fourth leaf (instead of a tendril)
What is the cap?
the sepals coming up and covering the flower (fused)
When does the cap come off?
at flowering, taking the petals with it
What percentage of flowers become berries?
30%
Cultivated vines are ____________ flowers.
perfect (hermaphrodetic)
Peduncle
Connects bunch to shoot
Pedicel
Connects berry to rachis
Rachis
the stem structure; important for considering when you want to do stem-inclusion
What came the first: the tendril or the cluster?
cluster
Cluster structure is _________.
variable (100-2000 flowers variation in a bunch)
What are the components of berries?
skin, pulp, and seeds
Do berries have a vascular system?
yes (in the skin)
Where are the majority of phenolics?
in the skin
Where is the biggest place to store sugar reserves after dormancy?
roots (all woody tissues store carbohydrates and roots are the biggest woody tissue)
Teinturier grapes
grapes whose flesh and juice is red in colour due to anthocyanin pigments accumulating within the pulp of the grape berry itself
What are the roles of the root system?
provides physical support for the plant in the soil
provides water and nutrient uptake
storage organ of carbohydrates and nutrients
When is the fastest period of growth for a vine in a season?
from budbreak to the first leaves; the vine is working off of storage
Fine roots
short lived but some percentage endure and become woody tissue
The number and placement of roots depends on…
soil structure, water, and nutrient availability
What is the range of the root biomass?
5-40 t/ha
The majority of roots are in the top _______.
0.5-1 m (this is where the nutrients are)
What are the 4 senses of the root?
nutrients, water, structure, gravity
What determines rooting angles?
genetics
(V. riparia Gloire, wide, shallow rooting, in wet environments)
(V. rupestris du Lot, narrow, deep rooting)
How many species do all rootstocks come from?
3
Low vigor rootstock has ________ rooting angles.
wide, shallow
High vigor rootstock has __________ rooting angles.
narrow, deep
Phenology
the study of natural phenomena that recur periodically in plants and animals, and of the relationship of these phenomena to climate and changes in season.
Why do we care about phenology?
It is important for site and cultivar selection, vineyard design, the timing of cultural practices, and the prediction of the future.
When do berries grow?
at night
When do leaves grow?
morning
Why is there no growth late in the day?
Internal pressure is a driving force for growth. There is less tension (pressure) in the vine later in the day due to heat so there is less growth.
What happens to grapevines in tropical climates?
They do not have uniform phenology; They grow throughout the year; they have multiple seasons throughout the year but with heterogenous development; hard to cultivate
What happens to grapevines in temperate climates?
They have uniform phenology due to going into dormancy
What are the distinct developmental stages?
Dormancy
Budbreak
Bloom/Flowering
Fruit Set
Veraison
Ripeness or Maturity
Leaf Fall
Dormancy
no visible growth, minimal metabolism; high concentrations of abscisic acid in the buds and woody tissues.
Why are vines cold hardy below 0˚C?
Sugar lowers the freezing point of the vine to -15 to -20˚ C.
Budbreak/Spring time
Remobilization of nutrients and pumping of sugar through xylem; the osmotic potential of the xylem sap leads to high (positive) hydrostatic pressure in the entire xylem… the vine is “crying”; reactivation of dormant buds; delivery of sugars in the absence of phloem flow enable the buds to resume growth and break
Buds are young, ____________ shoots.
compressed
Buds are formed by the ________________.
Shoot apical meristem
What protects the bud from freezing?
scales (perule)
Why choose to cane prune?
There is an inherent fertility to buds. Buds further up the shoot from the base tend to have higher fertility. Certain low vigor varieties require cane pruning to achieve a yield.
Lateral buds
gives rise to lateral shoots
Primary buds (dormant buds)
contains 3 separate buds and gives rise to 8-10 leaf primordia
Latent (secondary) buds
remain dormant for several years; can be fruitful, but are usually less fruitful
When do the secondary buds pushed?
When the primary bud is damaged or there is too much vigor.
Basal buds
Located at the base of a cane/shoot and can be lateral buds, primary buds, or secondary buds; also called crown buds
Budbreak is dependent on…
temperature
What are 2 types of shoot growth from buds?
fixed growth and free growth
What is fixed growth?
Occurs from leaf primordia and internodes pre-formed during bud development and is responsible for the rapid growth of the first 6-12 leaves.
When you cut a bud you would already seen these
What is free growth?
Occurs later and is production of new leaf primordia in the shoot’s apical meristem
Why are young red variety vines red?
There are anthocyanin present in the leaves and will turn green with chlorophyl production.
Apical dominance
growth starts from the most distal buds and produces auxin which inhibits growth below.
Favors vegetation closer to light for synthesis
Why is the period from bud break to the first 6-12 leaves the fastest?
To establish a canopy to start photosynthesizing
What are the visual signs of stopped growth?
When the leaves near the shoot tip are bigger and there are no smaller leaves.
When do berries stop growth in the season?
During veraison
When would grapevine growth not plateau and keep going?
When there is too much vigor
Where is most of the N in leaves?
chlorplasts
What happens to the vine after completing the shoot growth cycle and before it drops its leaves?
The vine remobilizes N (80%) C (50%) S (50%) and Fe (20%).
Dehydrates and gets ready for cold acclimation
Vascular sealing
What happens in a stress event when the canopy drops its’ leaves quickly?
It doesn’t remobilize and store the nutrients
Why do some growers irrigate vines after the harvest?
To alleviate stress for the vine so it will have a healthier system before going into dormancy
Where do clusters normally develop?
3rd to 6th nodes (3,4, and 6)
