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Muscadinia
Section
Euvitis
Section
Vitis
-- One Genus or Two?
The cultivated grapes belong to the genus Vitis. This
genus is distinguished from other genera of the family Vitaceae by having petals
which remain jointed at the top and separated at the base to fall as a calyptra
(a “cap?. There are two clearly distinct sections in this genus, the
Mascadinia and Euvitis, which differ in chromosome number (2n=40 and
2n=38, respectively) and therefore cannot be crossed successfully to give
fertile hybrids.
There are about 60 known
Vitis
species, mostly originated in the
Northern Hemisphere and are abundant in North America. There are native
Vitis
species in almost every state in
the United States. Species from Asia have been very little studied, but they
seem to show an interesting parallelism with the American species.
Muscadinia
Muscadine grape is one of the American Species, its
vines have smooth, persistent
(non-shedding) bark with prominent lenticels; nodes are without a diaphragm;
tendrils are simple; clusters are short and small; small bunches and berries
have very thick, tough skins and drop as ripen; and seeds are oblong, without a
beak (for detail).
There are only three species in
this section. The best known is V. rotundifolia, the muscadine grapes,
which were originated in the southeastern United States and domesticated by
European settlers since the European grapes won’t survive the diseases in that
region. The wild muscadine grapes, like other Vitis species are dioecious
(separated male and female flower). This is why some of the muscadine cultivars
need male plants to supply pollen. Other species in this section include V.
munsoniana (in Florida and the Bahamas) and V. popenoe (in Mexico).
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Euvitis
Euvitis
species have longitudinally striate-fibrose shoots, shedding at maturity; pith
is interrupted in the nodes by a diaphragm; tendrils are forked; flower clusters
are most elongated; berries adhere to the stems at maturity; and seeds are
pyriform, with a long or short beak (for
detail).
Most cultivated grapes belong to section Euvitis. All the species in this
section are interbred easily whenever attempted.
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Vitis vinifera
(European grapes) Vinifera produces most famous, popular and quality
wines. It was originally native to Asia
somewhere near the Caspian Sea, but was imported to Europe in prehistory.
They followed European colonies around the world, coming to North America
around the 1600’s, and to Africa, South America and Australia. In North
America it hybridized with native grape species. Vinifera
has large, jagged leaves, and its stem bark tends to peel. The grapes may be
green, red, or purple. Since vinifera is not resistant to Phylloxera, it
has to be grafted to North American rootstocks in regions with Phylloxera.
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Other American Grape Species:
Please note, besides Muscadine grapes, other
American species used in grape production are limited to V. labrusca
(concord grapes) and V. aestivalis (mostly Norton). The rest American
species are mostly used in breeding programs for hybrid American
cultivars, French hybrids or rootstock cultivars.
Vitis labrusca
(the fox grape, bunch grape) The North American table and grape
juice grapes, sometimes used for wine. This species has the largest but also
the most highly, and to many people unpleasantly, flavored berries. Vines
are strong with large, thick leaves. The upper leaf surface are usually dull
green, the lower surface are densely covered with white to brownish or
reddish hairs. V. labrusca differs from other species in having
tendrils at all nodes beyond the base of the shoot, instead of every third
node being missing a tendril. ‘Concord?and related cultivars are in this
species.TOP
Vitis aestivalis
Native to southeastern United States. It is a strongly growing species with
leaves resembling those of V. labrusca except that the hairs on the
lower surface tend to be in tufts and are rusty or red-brown in color. The
fruit is always black but without the intense flavor of V. labrusca.
The variety Norton is used for winemaking.
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Vitis riparia
(river bank grape) A wild grape of North America.
This species is the most widely distributed one in the northern United
States. It is a vigorous, tall-growing vine usually occurring along streams.
Some of them have been used in developing cultivars for cold and disease
resistance, especially in Elmer Swenson and University of Minnesota’s
breeding programs. It also has been used as rootstocks.
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Vitis berlandieri
A stocky, moderately climbing vine, found
on the limestone soil of southwestern Texas and adjacent areas of Mexico. It
has medium to large, slightly 3-lobed leaves, glossy above and becoming
hairless below as they expand to full size. The bunches are more branched,
carrying numerous small berries. The fruit ripens very late, high in sugar
and acid, and is juicy with somewhat a pleasant taste. It is very difficult to
root from cuttings. V. berlandieri is mostly used for
rootstocks.
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Vitis rupestris
This species is unusual in
being a small, multi-branched shrub which only becomes slightly climbing
under favorable conditions. Their roots tend to penetrate vertically instead
of spreading laterally as in other species. The leaves are small, of a
characteristic kidney shape, wider than they are long, and light
silvery-green. The bunches are small with small black berries, which is ok
in flavor. V. rupestris are used for making hybrid wine grapes and
for pest-resistant rootstocks.
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Vitis cinerea
It is similar to V. berlandier but grows in
wetter situations. The bunches are larger and looser, with numerous small
black berries. The fruit ripens late, becoming sweet and pleasant after frost.
V. cinerea are used mostly for rootstocks.
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French Hybrid
Hybrids in viticulture usually means French/American hybrid cultivars. They
come from controlled crosses between certain native American species and
V. vinifera created in Europe, as a result of resistance of phylloxera
devastation of the 19th Century. Hybrid cultivar wines are not so high
quality as European grape wines.
The French hybrids developed in the United States, however, have been
successful, for example, Cayuga White, a cross from Seyval (French) and
Schuyler (American) from New York Agricultural Experiment Station.
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(The part below is from
http://winemaking.jackkeller.net/vitis.asp. I think it is interesting.)
Pierre Galet, in A Practical Ampelography: Grapevine
Identification (1979), sowed a seed for thought. In "Appendix 1" (The
Genus Vitis) of his work, he noted the general characteristics of the genus
and then divided it into two sections, the Vitis Section and the Muscadinia Section. This jarred my memory sufficiently to recall that
Thomas V. Munson, in 1909, had divided vitis into two "sections" --
the true grapes (Euvitis) and pseudo grapes (Lenticellosis).
Munson placed two species in the latter -- (Vitis Rotundifolia and Vitis Munsoniana -- but Galet added a third --
Vitis Popenoi.
This division is more than just interesting.
Both Galet and Munson based the division on such basic
differing characters as forked (Vitis) versus unforked (Muscadinia)
tendrils, pyriform (Vitis) versus navicular (Muscadinia)
seeds, the presence (Vitis) or absence (Muscadinia) of a
diaphragm interrupting the pith at the node, and so on. There are, in all,
13 such morphological, anatomical and cytological differences noted, but it
is the first listed by Galet (but unknown to Munson in 1909) that speaks the
loudest to me -- (Vitis) has n=19 basic chromosomes, while (Muscadinia)
has n=20. Further, crosses between the Vitis species will produce
viable and fertile descendents, just as crosses between the Muscadinia
species will also produce viable and fertile descendants, but crosses of
species between the two sections fail. This is not a trivial matter. Galet's
suggestion that Muscadinia could, in fact, constitute a new genus of
Ampelopsis is quite compelling. However, until there is wide
agreement on this (and there isn't), I shall continue as my predecessors in
classifying all grapes as genus Vitis. Still, the differing
characters between (Vitis) and (Muscadinia) are useful in
identification by exclusion of North American natives in the southeastern
United States and Mexico.
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?/span> The number of basic chromosomes
is n=19 or 2n=38.
?/span> The canes have an inner corky
layer, outside of which is the bark (including the pericyclic fiber, the
primary and part of the secondary phloem) which may shed in strips at
maturity.
?/span> The secondary phloem has
alternating tangential layers of hard and soft phloem.
?/span> The secondary wood is soft with
large vessels.
?/span> There is a substantial amount of
pith.
?/span> A section of the shoot or cane
is always elliptical and never quadrangular. There is a diaphragm which
interrupts the pith at the node.
?/span> The tendrils are opposite the
leaves, two- or three-forked.
?/span> There are woolly, bristly or
special hair types on the vegetative organs.
?/span> The clusters have numerous
berries that adhere to the stem until maturity or beyond.
?/span> The berries have a sugary and
acid juice suitable for eating fresh or making juice or wine.
?/span> The seeds are pyriform.
?/span> The leaves are generally palmate
with five principal veins.
?/span> All the species of this section
are graftable on each other, but grafting with species from Muscadinia
has been found unfeasible. The species in this section will root from
cuttings.
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?/span> The number of basic chromosomes
is n=20 or 2n=40.
?/span> The canes have prominent
lenticels because of the corky layer just beneath the epiderm. Only the
epiderm -- not the bark -- falls off at maturity.
?/span> The phloem fibers of the
secondary phloem are radically placed, like two uneven columns, underneath
the pericycle.
?/span> The wood is hard, without large
vessels.
?/span> There is little pith.
?/span> There is no diaphragm
interrupting the pith at the node, so the pith is continuous from one end of
the cane to the other.
?/span> The tendrils are opposite the
leaves, always simple and intermittent.
?/span> The vegetation is always
glabrous or nearly glabrous.
?/span> The clusters have relatively few
berries that ripen unevenly and drop off one by one at maturity.
?/span> The berries are pulpy, with
little juice, but generally have low concentrations of sugar and are less
suited for vinification.
?/span> The seeds are navicular with an
oval chalaza surrounded by radiating ridges and furrows.
?/span> The leaves are always palmate
and nearly entire without lobing.
?/span> Grafting between species of this
section has not been tried because there is no practical interest in it.
Grafting with species from Vitis has not been successful. The species
in this section will not root from cuttings, but do root by layering.
For the home
winemaker, these differences have modest to severe potential consequences.
It certainly is worth knowing that three species, in general, are less
suited for winemaking that all the others. At the same time, I would submit
that there are more than a few suitable wine grape among the Rotundifolia,
so this is not a hard and fast rule. If you collect wild grapes for wine as
I do, it is also worth knowing that the Muscadinia tend to drop their
fruit as they mature. Finally, when using native plants as rootstock for
grafts, it is essential to know that the Muscadinia will not accept
grafts from Vitis cuttings, nor will they root as cuttings. These,
indeed, are important data.
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