Introduction
In
the Vitaceae family, grapevines are typically placed in the genus Vitis. The
Virginia creeper (P. quinquefolia) and Boston ivy (Parthenocissus tricuspidata)
are two more well-known members of the family. Members of the Vitaceae family
usually have a climbing habit, alternating leaf development on the stems, and
enlarged or jointed nodes that produce flower clusters or tendrils in the
opposite direction from the leaves. The tiny, bisexual or unisexual flowers
grow in big clusters. The stamens develop opposite the petals, and the majority
of the flower's components are grouped in groups of fours and fives. Two
carpels make up the ovary, which is partly encased in a receptacle that
eventually matures into a two-compartment berry with up to four seeds.
Vitis vinifera |
Flower arrangement of Vitis Vinifera |
The
family Vitaceae is primarily tropical to subtropical in nature, with perhaps
over a thousand species distributed among 15–16 genera. Vitis, on the other
hand, is mostly a temperate zone genus that is native to the Northern
Hemisphere. Acareosperma, Ampelocissus, Ampelopsis, Cayratia, Cissus,
Clematicissus, Ampherocissus, Parthenocissus, Pterisanthes, Pterocissus,
Rhoicissus, Tetrastigma, and Yua are genera that are related.
Genus Vitis
The
main characteristic that sets grapevines apart from comparable genera is their
flowers. Generally speaking, the flowers are unisexual; they can be classified
as male or female depending on whether they have upright, functioning anthers
and a fully developed pistil, or if they have a functional pistil and produce
sterile pollen or recurved stamens. The fused petals, known as the calyptra or cap, break along the base from the receptacle but stay joined at the apex. When
fully grown, the petals fall off. Nectar swells are located at the base of the
ovary. They produce a subtle scent that draws insects that pollinate plants.
Early in the flower's development, the calyx's sepals degenerate and only form
as remnants. The fruit has a tart and juicy taste.
Traditionally,
the genus has been split into the sections, or subgenera, Vitis and Muscadinia.
The bigger of the two subgenera, Vitis (bunch grapes), includes all species
with the exception of V. rotundifolia and V. popenoei. These two belong to the
Muscadinia subgenus. Some taxonomists have separated the muscadine grapes into
their own genus, Muscadinia, because the two subgenera are sufficiently
different from one another.
Subgenus
Vitis members are distinguished by their lenticels-free shredding bark,
tangentially positioned phloem fibres, branched tendrils, elongated flower
clusters, fruit that sticks to the fruit stalk when it reaches maturity, and
pear-shaped seeds with a prominent beak and smooth chalaza. The distinct,
circular, depressed area on the dorsal (rear) side of the seed is known as the
chalaza. Muscadinia subgenus species, on the other hand, have radially arranged
phloem fibres, unbranched tendrils, prominent lenticels, no diaphragm
interrupting the pith at nodes, small floral clusters, berries that separate
individually from the cluster at maturity, and boat-shaped seeds with a
wrinkled chalaza.
The
2 subgenera also differ by the number of chromosomes; Vitis species contains 38
chromosomes while the Muscadinia have 40 chromosomes.
Geographic Origin of Vitis and Vitis Vinifera
It
is unknown where and when the Vitis genus evolved. Vitis species are currently
found in Asia, Europe, Central and North America, and northern South America
(the Andean highlands of Colombia and Venezuela). Species in the subgenus
Muscadinia, on the other hand, are limited to northern Mexico and the
south-eastern United States.
Based
on the impressions of fossilised leaves, numerous extinct species of Vitis were
hypothesised in the 1800s. Because of the questionable quality of the evidence,
these are no longer recognised as legitimate designations. Not only do a number
of unrelated plants have leaves with similar outlines, but grapevines differ
greatly in terms of dentation, lobbing, and leaf form. Although there is a huge
deal of interspecies diversity, there is somewhat more confidence in the more
distinctive form of seeds.
However,
because of morphological variation in seed samples, these identifications
remain tentative because they are based on relatively few specimens.
Furthermore, Vitis seeds and those from related genera like Tetrastigma and
Ampelocissus are similar. In Europe, grape fossil remains have been discovered
the most. Nonetheless, rather than the historical distribution of grape
species, this might more accurately reflect the distribution of paleobotanical
interest or the availability of suitable sedimentary deposits.
Domestication of Vitis Vinifera
Only
in the late 4th millennium B.C., specifically about 3200 B.C. from Jericho and
northern Iran, and around 2800 B.C. in Macedonia and Greece, does there exist
conclusive evidence of domestication. This is strikingly close to two millennia
after the earliest archaeological records of wine production. The latter,
however, is in line with the theory that agriculture will leave the Fertile
Crescent and extend into northern Iran and Anatolia. As a result, it's possible
that winemaking evolved alongside agriculture and even predates the anatomical
evidence of grapevine domestication that has been preserved.
A
further feature of the fruit pedicel that is important to archaeologists
studying domestication is its altered state. When the berries are removed from
a farmed Vitis vinifera bunch, the pedicel often breaks off the main stem
(rachis). On the other hand, the stems of wild vines are robust and the pedicel
rarely separates from the peduncle. Therefore, in archaeological remains, the
relative frequency of seeds that are still connected to the pedicel serves as
an indicator of domestication.
It is generally believed that domestication of Vitis vinifera occurred in or around Transcaucasia, or neighboring Anatolia (~ 4000 B.C.). The distribution of Vitis vinifera was likely similar to that in the mid-1850s, prior to the decimation brought on by the phylloxera invasion, because the climate was similar to what it is today.
Cultivar Origin of Vitis Vinefera
Common cultivated Grapes |
Morphological (ampelographic) comparisons provide more significant data regarding varietal origin. These data are most useful in cases when cultivars have diverged by somatic mutation from a common ancestor, as in the case of the colour mutants of "Pinot noir," "Pinot Meunier," "Pinot gris," and "Pinot blanc." Except in cases where somatic mutation modifies the progenitor's features, vegetative propagation preserves such traits. Sexual (seed) propagation, on the other hand, rarely yields offspring that resemble their parents. When sexual reproduction has been engaged, this tends to dilute differences in morpho-logical features and renders them poor indications of origin.
Discover
more about the fascinating history of Vitis vinifera, including how it was
domesticated in Transcaucasia and where varieties originated. Discover the
mysteries of grape evolution, comprehend the ways that geography and morphology
interact, and enjoy the rich history of this extraordinary fruit.
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