Lecture 1
What are the Class and Family of grapevines? Where did it originate? What are the characteristics of Genus Vitis?
Dicotyledoneae
Vitaceae
Hairly leaves with 5 veins, forked tendrils, bark that sheds at maurity
What are the 3 main varieties of Vitis vinifera based on the ORIGIN? What are their characteristics?
Occidentals: Western Europe; wine grapes; small, compact clusters & small berries
Pontica: Aegean, Black Sea, Eastern Europe; wine & raisins; medium-sized berries (seedless)
Orientalis: Middle East, Iran, central Asia; table grapes; large clusters & large berries (seedless)
Explain the functions & structures of roots & stems of grapevine.
Root: support, water & nutrient uptake, storage for sugar, nutrients & hormones
Stem: support, water & nutrient transport, storage for sugar, nutrients
What are the major vegetative stages of grapevine?
Budbreak (early spring) to leaf fall (fall)
Budbreak:
Shoot growth: strong apical dominance for 18-20 leaves (blooming time), then lateral shoots start to grow which is reinforced by high N availability until fruit set in mid summer. Lignification starts afterwards
Root growth: root biomass increases from budbreak to leaf fall but only few live longer to become structural roots; 30-60% of total net sugar are stored; more nutrients>less root growth
Explain the importance of berry production in BC (and Canada).
-BC accounts for 21.4 % national fruit production ($200M/yr)
-BC is the largest highbush blueberry producer in North America, 3rd largest export in BC
-2nd largest producer of cranberries (1/3 of national production)
-BC produces 50+ % raspberries of Canada
-Not so much strawberries
What are 3 varieties of rootstock and why are they used for rootstock?
Vitis riparian
Vitis rupestris
Vitis berlandieri
They are American varieties that are resistant to phylloxera, and tolerant to adverse soil conditions
Explain how a variety & a clone differ from each other
Variety: sexual reproduction; genetically distinct
Clone: asexual (vegetative) reproduction; genetically identical to the mother plant (with some clonal variation due to mutations)
Explain the 3 types of buds & how the dormancy differs from one another. What is a function of secondary buds of dormant buds?
-Prompt or lateral bud: they break the current season & give rise to lateral shoots
-Dormant/compound bud: they give rise to shoots next spring. Secondary buds are backup when the primary buds fail
-Latent: remains dormant for several years
What are the major phenological stages of grapevine? When do they occur during the season?
1. Dormancy
2. Budbreak
3. Blooming
4. Fruit set (fertilization)
5. Veraison (colour change, fruits develop at different rates)
6. Ripeness/maturity
7. Leaf fall
In a temperate climate, growth occurs from April to Oct/Nov (discontinuous cycle = growth & dormancy)
Explain the differences between lowbush & highbush bluberries
Lowbush: wild variety; grow low; grown in maritime provinces like Quebec; processed in IQF; shorter shelf life
Highbush: cultivated in BC (90+%); grow large; #1 fruit export in Canada; fresh + processed; longer shelf life 5-6 weeks
Which grape varieties have lime tolerance ?
Vitis vinifera
Vitis berlandieri
What are the 3 main varieties of Vitis vinifera based on the USES?
Table grapes
Raisin grapes
Wine grapes
Explain the different purposes between spur pruning & cane pruning
Depends on the fruitfulness of the basal buds
Bud fertility from basal to the tip: Low > High > Low
Basal buds fertility high -> spur pruning
Basal buds fertility low -> cane pruning
Explain the shoot growth of grapevines in the details. Keywords: dominance of apical buds, vigor, growth cycle, cane ripening
Shoot growth starts from the distal buds to the basal buds
The rate of shoot growth (vigor) is affected by genetic effects; temperature; soil moisture; vine reserve status (carbs stored)/pruning level/vine age
Apical buds dominance for 18-20 leaves
The growth cycle is completed with the recycling of nutrients from the leaves; abscission of leaves; dehydration & cold acclimation of all woody parts; phloem sealing
Cane ripening:
Shoot growth resumes after fruit set & starts to lignify to prepare for next season.
if cane ripening is good > high sugars in the wood > fruitful buds next season; favoured by light, temp, drought (less water inhibits shoot growth = more sugar stored), balanced yield (affects the stability of fruitfulness next year)
What are the 3 major advantages of the BC berry industry?
-Moderate coastal climate, long frost-free season.
-Fertile, well-drained soils and plentiful
water.
-Established infrastructure (a port for exporting goods to international markets) and technical expertise.
-Supportive agricultural policies (Agricultural Land Reserve in Fraser Valley, Right to
Farm).
Which Vitis varieties are cold hardy?
Vitis labrusca
Vitis riparia
Vitis aestivalis
Vitis amurensis
What has DNA analysis for worldwide grape varieties shown?
1st degree relationships of wine & table grape varieties
What are the morphological characteristics of cultivated grapevines?
-Not self-supporting, needs tendrils to climb
-Low investment in stems than trees (lower storage)
-Unusual stem anatomy: longer internodes, wide and long-lived vessels, lots of parenchyma cells, few fiber
-Fast growth
Explain the phenomenon of "bleeding" in grapevines.
= Xylem sap exudation after reactivation of roots in early spring
-caused by root reactivation and xylem sap exudation under positive hydrostatic pressure (~0.2–0.3MPa)
-occurs when soil T > 7–10°C
-the duration is 3-20 days
-serves as remobilization of nutrient reserves (sugars stored in parenchyma cells) and pumping into XYLEM > the sap rich in sugars, amino acids, ions, in the absence of phloem flow (not available during winter)
-signals the end of dormancy and rehydration of buds.
Explain the challenges of BC berry industry
-very rapid growth
-vary high cost of production (land, labour, chemicals)
-Labour availability
-Trade relations & the exchange rate
-Weather (cultivar not selected to adapt wet BC weather)
-Decline in pollinator population
-Pest & disease
Explain the differences between wild & cultivated varieties
Vitis sylvestris: Wild, dioecious in Asia & Europe, small leaves & fruits
Vitis vinifera: Originated in the temperate zones in Western Asia & Europe, monoecious (perfect flower), gave rise to most of the cultivars today, with larger leaves & compact, larger fruit
Explain the selection processes for a variety & a clone
Variety: Cross-fertilization of 2 genetically distinct parents > grow from seeds
Clone:
Mutant has a favourable trait (somatic mutation)
The mother vine is propagated vegetatively
A new clone with the trait is grown
Explain the fruit structure for seeded & seedless grapes. What are 2 seedless types?
Fruit = berry
exocarp = cuticle + epidermis + hypodermis
mesocarp = fleshy part, vacuolated storage parenchyma cells
endocarp = seed; embryo + endosperm + inner & outer integuments
Seeded: zygote, tegument & endosperm; max 4 seeds
Seedless:
1. Stenospermocarpy = imperfect seeds; zygote is fertilized but endosperm is not > smaller seeds
2. Parthenocarpy = true seedless; both zygote & endosperm are not fertilized > no seeds
How can the environment affect the vegetative cycles of grapevine
-Temperature: as T increases, photosynthetic activity increases > growth (yield) increases until T goes over threshold
-Day length:
Longer than 12 hr daylight = growth
Shorter than 12 hr daylight = no growth
Budbreak:
~8-10 °C; the rates are proportional to increasing temp; more rapid & uniform with chilling
timing varies among genetic backgrounds (V. vinifera = 10 °C > V. rupestris > V. berlandieri > V. riparia = 4.3 °C)