Progeny produced by asexual reproduction from an organism (branch or rice). 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 a starting plant. First of all, genetically identical living beings are created with heterogeneous properties that represent 100% identical copies (duplicates) of the initial type. By spontaneously arising and accumulating during the life phase mutations These copies differ slowly but steadily from the original vine in small steps. But only starting from a bigger one morphological and genetic modification scope one can speak of mutants. In the so-called somatic chimeric the mutations appear tissue-specific, that is, the outer epidermal cells may have one or more mutations, but these have not occurred in the inner cell layers or vice versa.
Such chimeras may even be the rule in the vine, because with the first divisions of the embryo, the principle dichotomy of the tissue layers in the epidermis and inner cell layers is determined to be deterministic forever. This dichotomy of the ground tissue is in each newly formed axillary bud already included, so that chimerism in the vegetative propagation over cuttings also be multiplied. On the other hand, in sexual reproduction two parent species are crossed, so that from each fertilized seed a new one vine which has half each of the newly combined genetic material of both parents. Thus, by targeted intersection breeding by gender, new grape varieties. However, somatic mutations and vegetative propagation give rise to clonal variants, mutants and chimeras.
The terms clone, mutant and clon mutant are commonly used synonymously in viticulture, 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 not more than 100 % is identical to the starting plant. Clones of grape varieties are only addressed in practice as clones, if they can be distinguished in some visible or measurable individual features at least slightly from the initial type, that is already mutated. Such mutations occur spontaneously and often as budding mutations. Later after the expulsion they are going through the vegetative propagation the mutated shoots multiplied.
Klonmutant is understood to mean a clone (duplicate) of a cultivar that differs in some characteristics. Clonmutants are formed by spontaneous mutation of a fruit impulse, which was selected due to its deviating properties and further propagated vegetatively. However, it's a bit of an inaccurate term, the boundaries between clones (which, strictly speaking, means a hundred percent duplicate), cloning mutant and mutant are fluent. Put simply, clonal mutants can be characterized by shifts in the quantitative characteristics (higher Mostgewicht, fewer earnings, more vigorous growth) than by clear visual boundaries due to qualitative features (berry color / form, leaf hair, precociousness). The Pinot varieties Blue Arbst. Frühburgunder. Pinot Liébault. Pinot Mariafeld. Pinot Tete de Negre. Pinot Teinturier and Samtrot are often different than clone, clonmutant, mutant, biotype or variety designated.
These mutants can mutate again and develop into independent mutation lines. So have especially in old, widespread and million-fold varieties such as Chasselas. Pinot or Traminer developed several regional lineages with independent grape clones. For example, very distinctive grape clones are plants whose berry color has changed 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 mutants. The berry color determining anthocyanins (red dyes) are biochemically generated in the cells in a chain of synthetic steps. By one or more mutations This chain is interrupted in the underlying genes, so that less color pigments or only the colorless precursors are formed. As a result, either the color is missing quite like the Pinot Blanc or it is formed less blue color and it creates the impression of a kind of mixed color as in Pinot gris, Both are from the Pinot Noir mutated and actually it is a grape variety.
In extreme cases, even one single grape has different colored berries. Apparently, this mutation can backmutieren, so that one occasionally Pinot Blanc with gray and white grapes on a plant. Although these color variants in blue, white or gray can not be distinguished either on the green leaf or genotypically, they were long ago given their own names and treated like independent grape varieties. Of course, the very different wine characteristics of the color variants also contributed to this. Another example is the genotypically identical "varieties" Gewurztraminer, Red Traminer and White Traminer, which differ only by different taste intensity of the berries and the wine. Although, strictly speaking, they are "only" mutated clonal variants, these varieties are still treated as stand-alone varieties, although all three are one variety Traminer are assigned.
This generally applied practice watered down the actually biologically quite clearly defined grape variety term. This is because the conspicuous variety varieties that have emerged from clone selection are mistakenly treated the same way 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, conspicuous cloning mutants act like Pinot Blanc or Pinot Meunier as a separate variety, although it is not seedlings of Pinot, but mutants of the Pinot Noir are. Although they are externally distinguishable, but genotypically not or hardly differentiated. If one grasps the variety term narrowly, then there would be firstly strains in the strict sense (seedlings from sexual propagation) and secondly from it varietal clones (mutants from vegetative propagation). In practice, however, everything is falsely referred to as an independent variety, which is somehow still visually distinguishable.
By the formerly usual massive selection (Mass selection) in the vineyard, mutants were deliberately or unconsciously propagated, so that clone diversity could evolve and survive for centuries. Regionally and especially in climatic or zonal boundary locations one finds climate-adapted clones, there for example frost (especially winter frost) always selected sharp. However, somatic mutations are unlikely to lead to major environmental adaptations, for example to newly introduced pathogens, since the mutation-induced clonal differences generally alter the physiology and biochemistry of the variety clones only quantitatively but not fundamentally. And adaptive changes of grape varieties on generative or sexual way are excluded because of the purely vegetative propagation yes (under adaptive is understood in the biology, the ability of organisms to actively adapt to changing environmental conditions).
In modern viticulture, all under one practice clone vines understood as a result of clone selection and testing of certain positive and selected individuals (accessions). These are planted in base plants, observed for several years and carefully tested for their viticultural properties. From these primary clones one selects the "best" mother vines, which after further testing and approval then in nurseries serve as a starting material for commercial mass propagation. Of these, the one-year fruit rods (Edelreiser) are separated, which to drive pieces with internode and each two knot-bearing nodes are cut. These are on reblausfeste documents grafted. So one can produce from a single mother plant up to 50 absolutely identical descendants.
These clone copies are initially genetically identical to the mother vine but can accumulate mutations over the decades. However, these young mutations in the vineyard are no longer relevant to breeding today, as in the modern, mostly only from a variety clone built and after 30 years again cleared economies Klonselektion is no longer operated. In the wine-growing countries, cloning is strictly regulated and officially controlled. Each clone receives a breeding number and must be officially recognized (like a new grape variety) for the production of quality wine. It is the virus-free of the breeding material is one of the essential prerequisites for approval. In France there are z. B. about 50 recognized clones of Pinot Noir, with quite different characteristics in detail.
In the nurseries As a rule, several different clones of grape varieties are available. However, they often differ only marginally, for example, in a statistically only over the years measurable, slightly increased earnings or a little higher sugar yield, These mass clones, which are mostly selected for maximum yields, do not reflect the actually developed clone variety of a grape variety, which in the case of old varieties in terms of morphological, biochemical and genetic differences can be quite considerable. By the commercialization of the vegetative vine propagation in nurseries 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 are descended from a single parent plant and are therefore genetically identical. But it is becoming common again to use different clones of a 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,
Pictures: Ursula Bruehl, Doris Schneider, Julius Kühn Institute (JKI)