Topic 1 - Grapevine classification and ampelography

Question 1

What is the order, family, genus, and species of the grapevine commonly used in viticulture?

Answer 1

The grapevine commonly used in viticulture is classified in the order Rhamnales and family Vitaceae.

The vast majority of grapevines grown for commercial grape production are in the genus Vitis and belong to the species vinifera

Question 2

Why are grapevines sometimes described as belonging to the order Rhamnales or sometimes Vitales?

Answer 2

Rhamnales or Vitales
According to the prescribed textbook, vines belong to the order Rhamnales, which has three families - Rhamnaceae, Leeaceae and Vitaceae.

However, according to Angiosperm Phylogeny Group IV (2016), grapevines are separated from Rhamnales, and belong to order Vitales, which has only one single family, i.e., Vitaceae.

Question 3

Grapevines belong to the family Vitaceae.

What are some of the features of plants in the family Vitaceae?

Answer 3

It is thought to encompass at least 850 species assigned to 12 to 14 genera depending on the classification scheme used.

The Vitaceae are widely spread in the temperate and tropical zones of the world including Australia.

The members of this family are typically climbing plants with a leaf-opposite tendril pattern.

Question 4

At the genus level, how many accepted classification schemes exist for grapevines?

What are these classification schemes?

Answer 4

At the genus level (i.e., Vitis), there are two accepted classification schemes for grapevines.

The first of these divides the genus Vitis into two sub-genera, Euvitis and Muscadinia, while the second regards Muscadinia vines as a distinct genus from Vitis.

Question 5

What genus’ is viticulture concerned with?

Answer 5

Of the genera in the Vitaceae family, only the genus Vitis and Muscadinia concern us, as cultivated grapevines belong to those genera.

Question 6

What is a major difference in the flowers of wild and cultivated Vitaceae grapevines?

Answer 6

Most Vitaceae have perfect flowers, however, the wild Muscadinia and Vitis species have imperfect male or female flowers on different plants (i.e., dioecious).

Question 7

What are the morphological features common between Vitis and Muscadinia vines?

Answer 7

• simple leaves;
• generally unisexual flowers, i.e. male or female (monoecious);
• flowers that separate at the base and remain joined at the top, forming a ‘calyptra’ or cap;
• the berries are soft and pulpy.

Question 8

Why are crosses between Muscadinia and Vitis vines rare?

Answer 8

• they contain a different number of chromosomes, Vitis has 38 and Muscadinia 40.

Question 9

What are some differences between Muscadinia and Vitis vines?

Answer 9

• Muscadinia has 40 chromosomes, and Vitis has 38
• Muscadinia has simple tendrils, whereas Vitis has forked tendrils
• Muscadinia has lenticels (i.e. breathing pores) present on bark, whereas lenticels absent from bark of Vitis
• Muscadinia bark is nonshredding, whereas bark shred when Vitis is mature
• Muscadinia seeds are oblong, whereas Vitis seed are pear shaped
• Muscadnia do not root by cuttings, so propogration is achieved by layering, whereas Vitis propagate from rooted cuttings.

Question 10

What are the three species of Muscadinia?

Answer 10

Muscadinia rotundifolia
Muscadinia munsonia:
Muscadinia popenoe:

Question 11

What are two key distinguishing features of the Vitis genus?

Answer 11

• All members of this genus are perennial vines or shrubs with tendril-bearing shoots.
• A distinguishing feature of the Vitis genus relates to the structure of the flowers.
• At flowering the petals remain to attached to the top and detach from the base of the flower to form a calyptra or cap.

Question 12

What are the major groups Vitis is often divided into?

What are the major differences between the two groups?

Answer 12

Eurasian:
- neutral, palatable flavour
- tendrils always discontinuous, every third node missed
- pulp tends to cling to the skin
- anthocyanins present as monoglucosides
- large seeds

American
- strong ‘foxy’ flavour (methyl anthranilate)
- in V. labrusca, the tendrils continuous (i.e. tendrils opposite each leaf)
- pulp slips from the skin
- anthocyanins present as diglucosides
- small seeds

Question 13

Describe the American group of Vitis vines.

Answer 13

• contains about 8 to 34 species
• generally have thinner shoots with longer internodes and less prominent nodes and strictly dioecious if native to North America.
• leaves have shallow sinuses and often a glossy surface.

Question 14

Why did American settlers struggle with the domestication of the American group of Vitis?

Answer 14

The disadvantages of pungent flavours, small berries and seeds proved difficult to overcome.

Question 15

American V. labrusca variety such as Concord, Catawba, Isabella and Niagara are widespread in their home countries, but less so elsewhere due to their strong ‘foxy’ flavour.

What are they grown for?

Answer 15

• disease resistance, particularly downy and powdery mildew;
• greater winter hardiness; and
• tolerance of high relative humidity.

Question 16

What are the species V. riparia, V. rupestris, V. champinii (e.g. Ramsey) and V. berlandiera used for?

Answer 16

Used as root stock mainly for their resistance to phylloxera.

Question 17

What is the most common species, used for wine, table and drying grapes?

Answer 17

V. vinifera is the most common species, used for wine, table and drying grapes.

Question 18

Where does the V. vinifera species come from?

Answer 18

V. vinifera occurred naturally in both Asia and Europe, and is the most well-known of the Eurasian species as the 25-30 Eastern Asian species are relatively unknown.

Question 19

What is V. vinifera resistant to? What is it susceptible to?

Answer 19

This species is resistant to crown gall, downy mildew, anthracnose and Bortrytis, but susceptible to phylloxera.

Question 20

How many cultivars (varieties) exist in the Vitis vinfera species?

Answer 20

• up to 8,000 cultivars (varieties)
• of which probably 1,000 are relevant in the wine growing countries of the world.

Question 21

Why are there many different clones of Pinot Noir available?

Answer 21

• Different clones of a variety arise as a result of a mutation event that occurs in a cell of a bud that is destined to become a shoot.
• Some varieties are more prone to these mutations, Pinot Noir is a good example and hence there are many different clones of Pinot Noir available.

Question 22

What are the four most common methods for grouping V. vinifera varieties?

Answer 22

The four most common methods involve grouping on the basis of place of origin, climate of origin, viticultural characteristics and winemaking characteristics.

Question 23

How do grapevine clones arise?

Answer 23

• Clones arise when a given grapevine variety, e.g. Chardonnay is repeatedly propagated by asexual reproduction.
• This is because over time, spontaneous DNA mutations occur in the genetic make-up of the parent plant.
• In the majority of cases, these DNA mutations are of no consequence, but occasionally they result in subtle differences.
• Sometimes these minor differences can have an impact on the properties of the vine that are significant in terms of wine production.

Question 24

What are the levels of taxonomic classification?

Answer 24

Kingdom
Division
Class
Order
Family
Genus
Species
Variety or cultivar

Question 25

What is ampelography?

Answer 25

Vine identification. The term ampelography is derived from the Greek language, (‘ampelos’ meaning ‘vine’ and ‘graphy’ meaning ‘identification’).

Question 26

What are three different classification systems used in ampelography?

Answer 26

- the morphological classification which considers the characters of each particular organ of the vines, such as growing tips, leaves, shoots, clusters etc. - the physiological classification based on the budding time of different varieties, the date of fruit maturation, and the time of defoliation. - the phonological classification primarily based upon the morphological characters of the growing tips, shoots, and leaves, and secondarily upon clusters and berries.

Question 27

What are genotypic characters?

Answer 27

- characters that are inherited - unique to a particular variety - include factors such as leaf, berry, and bunch shape, and types of hair on the leaf

Question 28

What are phenotypic characters?

Answer 28

- relate to the environment and growth stage of organisms - e.g., yellowing of the leaves are not a genotypic feature but are more likely due to environmental effect, such as low N

Question 29

What are wooly hairs? What are some further descriptions of wooly hairs?

Answer 29

- these are long, intertwining hairs spread out over the plant surface. - Felty: completely cover the plant surface and cannot see its own colour. - Downy: can see the plant surface colour. - Cobwebby: few hairs as spider’s web.

Question 30

What are pubescent (setose) hairs?

Answer 30

- short, colourless hairs, almost perpendicular to the surface of the plant, commonly referred as ‘bristly’. - when they are dense and fine, also described as ‘velvety’.

Question 31

What are special hairs?

Answer 31

- Curved, thornlike hairs on the shoots and petioles: Vitis armata and Vitis Daviddii. - Peculiar hairs, enlarged at the tip, on the shoots, petioles and veins: Vitis Romanetii. - Dark, stiff hairs on shoots only: Vitis labrusca and Vitis cordifolia.

Question 32

What does indument refer to in the ampelography of the growing tip?

Answer 32

Indument refers to the coverage of hair, from low to high covering density, can be described as glabrous (no hair), thick or thornlike hair, pubescent, cobwebby, downy, and felty. Varieties can be both thornlike or pubescent and woolly hairs.

Question 33

How is the form of the growing tip distinguished in the ampelography of grapevines?

Answer 33

- Globular: leaves are pressed together around the tip, resembling a heart of lettuce, e.g., V. riparia. - Open: young leaves separate early from the tip and relatively flat, e.g., V. monticola.

Question 34

What are the basic features of most leaves in Vitis?

Answer 34

Most leaves are palmate (i.e., all main veins arising from a single point). These leaves have five large, principal veins and determines five lobes.

Question 35

What are the 5 leaf shapes used in the amepelography of grapevines?

Answer 35

1. Cordiform (heart-shaped) 2. Cuneiform (shield-shaped) 3. Truncate (similar to cuneiform, but with shorter L3 vein) 4. Orbicular or round (imperfectly round) 5. Reniform ( kidney-shaped)

Question 36

How many lobes do grapevine leaves typically have?

Answer 36

- Grapevine leaf typically has five lobes based on the five main veins branching out from the petiolar junction. - Sometime, more than five lobes could be identified on one leaf, due to deep sinuses being formed between secondary branches of main veins.

Question 37

What shape does the petiolar sinus usually form?

Answer 37

- a U, V (generally very shallow or almost non-existent) or lyre shape. - The base of the sinus can be wide (club-shaped) or narrow (pointed). - The lobes at either side of the petiolar sinus can overlap completely, hiding the sinus, partially, or not at all.

Question 38

What is a naked petiole sinus?

Answer 38

If the petiole sinus is delineated by one or both of the lateral veins (L3 or L’3), it is called naked, such as Chardonnay.

Question 39

What are the four rough classification groups for dentation or teeth of grapevine leaves?

Answer 39

1. Pointed: with straight sides. 2. Convex: arched, both sides curved outward. 3. Concave: both sides curved inward. 4. Hooked: one side convex and one side concave.

Question 40

How do the shoots of wild and cultivated vines differ? How do the shoots of V. vinifera and some American species differ?

Answer 40

Wild vines generally have longer and thinner shoots than cultivated vines. V. vinifera can form primary lateral shoots, while some American species and their descendants can produce secondary and even tertiary laterals.

Question 41

The different grapevine species also show different tendril placement. It can be:

Answer 41

Continuous: all nodes except for the first three or four from the base have a tendril. E.g., V. labrusca, Concord; - Subcontinuous: some nodes have no tendrils, but at least three successive nodes have; - Intermittent: never more than two nodes have tendrils in succession. The most common placement.

Question 42

How can bunch size differ?

Answer 42

- Bunch size can vary from less than 6 cm in length to greater than 24 cm in length, with weights of 50-1000 g.

Question 43

Bunch shape varies depending on the amount of branching. What are some definitions of bunch shape?

Answer 43

- Cylindrical bunch: the bunch only has primary lateral branches of equal length. - Conical bunch: the length of the laterals becomes shorter and shorter towards the tip of the cluster. - Shouldered bunch: bunch with very well-developed laterals near the peduncle. If the first lateral branch closest to the peduncle grows large and separates from the cluster, it is called a wing.

Question 44

What does cluster compactness describe? What are two different descriptions of compactness?

Answer 44

Cluster compactness describes the amount of space between the berries. - The cluster is loose if berries are separate from each other. - On the contrary, if the berries are pressed tightly against each other, the cluster is compacted.

Question 45

Why is the Cabernet Sauvignon leaf distinctive?

Answer 45

- The petiole sinus is tends to be flask shaped, and the lobes overlap.

Question 46

Why do not use leaf size and colour in ampelography?

Answer 46

- Leaf colour dependant on nutritional status of the vine and leaf size is dependant on the age of the leaf.

Question 47

How does growing a grapevine from seed allow for the potential to produce novel varieties?

Answer 47

- A grapevine grown from a grape seed will not be genetically identical with the parent, and as such provides a potential to produce novel varieties. - In the vast majority of instances these offspring will be weakly growing and have inferior qualities in terms of grape and wine production.

Question 48

What is a intra specific hybrid? What is a cross/ hybrid?

Answer 48

If two species that are crossed are the same, i.e. V. vinifera var.1 crossed with V. vinifera var.2, then the resulting progeny are described as intra specific hybrids. If the cross involves two different species such as V. vinifera and V. labrusca then the resulting progeny are described as inter specific hybrids, and termed as ‘hybrid’.

Question 49

Why is hybridisation carried out? What is an example?

Answer 49

Hybridisation is carried out to develop a new variety with specific desirable traits. E.g., America interspecies hybrids were developed to counteract the cold harsh conditions of NE America. This involved crossing varieties native to this part of the world that were cold tolerant with V. vinifera that had the desirable qualities for wine production.

Question 50

What is an alternative method to develop new varieties that is less labour intensive? Why is this method prohibited in Australia?

Answer 50

An alternative method to develop new varieties which is less labour intensive is to genetically modify the grapevine. This can involve the insertion of a gene for a particular trait (e.g. disease resistance) or the deletion of a gene (e.g. the gene that causes browning in dried grapes, a poly phenol oxidase enzyme). However, due to consumer concerns, particular in export destination countries the use of genetically modified organisms (GMOs) is prohibited within the Australian wine industry.

Question 51

How have advances in molecular biology techniques opened up opportunities to breed new varieties of grapevines?

Answer 51

Applying the molecular knowledge that we have of the grapevine to assist classical breeding programs rather than by genetically modifying organisms.

Question 52

What are some of the traits that would suggest to taxonomists that Muscadine vines should be considered as belonging to the same genus as Vitis?

Question 53

What are some of the traits that can be used as an argument that Muscadine vines are clearly in a distinctive genus from Vitis vinifera?

Question 54

What is the difference between a grapevine variety and a grapevine clone?

Question 55

Why can’t the size of the leaves on grapevine be used in ampelography?