Offspring (as a branch or rice) that have emerged from an organism through asexual reproduction. In humans, identical twins form a natural clone. In plants this is called vegetative propagation, when new plants are regenerated from certain tissue parts of an original plant. First of all, genetically completely identical creatures with hereditary characteristics are created, which are 100% identical copies (duplicates) of the original type. Through spontaneously occurring and accumulating during the life phase mutations these copies slowly but steadily deviate from the starting vine. However, only from a certain larger morphological and the extent of genetic change can be called mutants. With the so-called somatic chimeric If the mutations occur in a tissue-specific manner, that is to say that the outer epidermal cells can have one or more mutations which, however, have not occurred in the inner cell layers or vice versa.
Such chimeras may even be the rule for the vine, because with the first division of the embryo, the basic division of the tissue layers into the epidermis and inner cell layers is determined forever deterministically. This division of the basic tissues into each is newly formed axillary bud already included, so that chimerisms in vegetative propagation over cuttings can also be multiplied. On the other hand, in the case of sexual reproduction, two parent varieties are crossed, so that a new one is created from each fertilized seed vine grows out, half of which has the newly combined genetic makeup of both parents. So, through targeted crossings breeding sexually new grape varieties. However, somatic mutations and vegetative propagation result in clone variants, mutants and chimeras.
The terms clone, mutant and clone mutant are often used interchangeably in viniculture, but this is not correct, because a clone in the strictly scientific sense is an identical copy of the original, while a clone in the viticultural sense represents a mutated clone variant and no longer 100 % is identical to the original plant. In practice, clones of grape varieties are only referred to as clones if they can be at least slightly differentiated from the original type in some visible or measurable individual characteristics, i.e. if they have already mutated. Such mutations occur spontaneously and often as bud mutations. Later after expulsion they will be through the vegetative propagation the mutated shoots reproduced.
A mutant clone is understood to mean a clone (duplicate) of a variety which differs in some features. Clone mutants arise from the spontaneous mutation of a fruit shoot that has been selected for its different properties and has been vegetatively propagated. However, it is a somewhat vague term, the boundaries between clone (which actually means a 100% duplicate), clone mutant and mutant are blurred. Put simply, mutant clones are more likely to be characterized by shifts in quantitative characteristics (higher Mostgewicht, fewer earnings, stronger growth) than through clear visual demarcations due to qualitative characteristics (berry color / shape, leaf hair, early maturity). The Pinot varieties Blue work. Frühburgunder. Pinot Liébault. Pinot Mariafeld. Pinot Tete de Negre. Pinot complexion and Samtrot are often different as a clone, mutant clone, mutant, biotype or variety designated.
These mutants can mutate again and develop into independent mutation lines. So, especially with old, widespread and million-fold varieties like Chasselas. Pinot or Traminer developed several regional lineages with independent grape clones. Very conspicuous grape variety clones are, for example, plants whose berry color has mutated from blue to violet, gray or red or to yellow and green. Grape varieties such as Chasselas Blanc, Chasselas Rose and Chasselas Rouge, as well as Pinot Gris and Pinot Blanc and many others are such berry color mutants. Determine the berry color anthocyanins (red dyes) are produced in the cells biochemically in a chain of synthetic steps. By one or more mutations this chain is interrupted in the underlying genes, so that fewer color pigments or only the colorless precursors are formed. As a result, either the color is missing, as with Pinot Blanc or less blue color is formed and the impression of a kind of mixed color is created as with Pinot gris, Both are from the Pinot Noir mutated and actually it is a grape variety.
In extreme cases, you can even find differently colored berries on a single grape. Apparently, this mutation can mutate back, so that Pinot Blanc with gray and white grapes is occasionally found on a plant. Although one cannot distinguish these color variants in blue, white or gray from the green leaf or genotypically, they were given their own names a long time ago and treated like independent grape varieties. The quite different wine characteristics of the color variants naturally contributed to this. Another example are the genotypically identical "varieties" Gewurztraminer, Red Traminer and White Traminer, which differ only in the different taste intensities of the berries and the wine. Although strictly speaking it is "only" mutated clone variants, these variants are still treated as independent varieties, although all three of the one variety Traminer are to be assigned.
This generally applied practice, however, dilutes the concept of grape variety, which is actually clearly defined biologically. Because the conspicuous variety variants resulting from clone selection are incorrectly treated the same as the varieties resulting from seedling propagation (only these can be described as independent in the strict sense). Genotypically differentiable varieties are always selected seedlings, In practice, striking clone mutants act like Pinot Blanc or Pinot Meunier just as an independent variety, although it is not a seedling of the Pinot, but mutants of the Pinot Noir are. Although they can be distinguished externally, they are genotypically not or hardly differentiated. If you narrowly define the variety term, then there would be firstly varieties in the strict sense (seedlings from sexual reproduction) and secondly, resulting variety clones (mutants from vegetative propagation). In practice, however, everything is wrongly referred to as an independent variety, which is somehow still visually distinguishable.
By the usual way massive selection (Mass selection) in the vineyard, mutants were consciously or unconsciously propagated, so that clone diversity could develop and be preserved over centuries. Regionally and especially in climatic or zonal border areas, climate-adapted clones can be found, for example frost (especially winter frost) always selected. Larger environmental adaptations, for example to newly introduced pests, are not to be expected due to somatic mutations, since the mutation-related clone differences usually only change the physiology and biochemistry of the variety clones quantitatively, but not fundamentally. And adaptive changes to grape varieties generative or sexual path are excluded because of the exclusively vegetative propagation method (adaptive in biology means the ability of organisms to actively adapt to changing environmental conditions).
In modern viticulture everyone is under a practice clone vines understood, which resulted from the clone selection and examination of certain, positively conspicuous and selected single floors (accession). These are planted in base plants, observed for several years and carefully checked for their viticultural properties. From these primary clones you select the "best" mother vines, which after further testing and approval then in nurseries serve as the starting material for commercial mass multiplication. From these, the annual fruit rods (fine rice) are separated, which form shoots with internode and cut two bud-carrying knots each. These are phylloxera-proof documents grafted. So you can produce up to 50 absolutely identical descendants from a single mother plant.
These clone copies are initially genetically completely identical to the mother vine, but can also accumulate mutations over the decades. However, these young mutations in the vineyard are no longer relevant for breeding nowadays, since clone selection is no longer carried out in modern commercial facilities, which are usually only made up of one variety clone and have been cleared again after 30 years. In the wine-growing countries, cloning is strictly regulated and officially controlled. Each clone receives a breeding number and (like a new grape variety) must be officially recognized for the production of quality wine. Here is the virus-free of the breeding material is one of the essential requirements for approval. In France there are e.g. B. around 50 recognized clones from Pinot Noir, with very different properties in detail.
In the nurseries there are usually several different clones of grape varieties available. However, they often differ only marginally, for example in a somewhat increased, statistically only measurable over the years earnings or a little higher sugar yield, These mass clones, which are mostly selected for maximum yields, do not reflect the actually developed variety of clones of a grape variety, which in old varieties with regard to morphological, biochemical and genetic differences can be quite considerable. By commercializing the vegetative vine propagation In vine schools and the one-sided focus on a few practice clones, the clone diversity of most grape varieties has already shrunk to a few surviving specimens, which are also often viral. This means that all vines in a vineyard stem from a single mother plant and are therefore genetically identical. But it is slowly becoming common to use different clones of one variety in a vineyard in order to achieve a certain risk diversification. See further information under the keywords DNA. mutation. Certification of vines and breeding,
Images: Ursula Brühl, Doris Schneider, Julius Kühn Institute (JKI)