Offspring produced from an organism by asexual reproduction (Greek: branch or rice). In humans, identical twins form a natural clone (but with different fingerprints). In plants, this is called vegetative reproduction, when new plants are regenerated from certain tissue parts of an initial plant. In the process, genetically completely identical living beings with hereditary characteristics are initially created, which are 100% identical copies (duplicates) of the original type. Due to spontaneously occurring mutations that accumulate during the life phase, these copies slowly but steadily deviate from the original vine in small steps. However, one can only speak of mutants from a certain larger morphological and genetic scope of change.
Somatic chimeras
In somatic chimeras, the mutations occur in a tissue-specific manner. The outer epidermal cells or the inner cell layers may show one or more mutations. Such chimeras may even be the rule in grapevine, because with the first divisions of the embryo, the basic division of the tissue layers into epidermis and inner cell layers is deterministically established forever. This division of the basic tissues into two is already also contained in each newly formed axillary bud, so that chimerisms are also multiplied during vegetative propagation via cuttings. In sexual reproduction, on the other hand, two parent varieties are crossed so that from each fertilised seed a new grapevine variety grows out, half of which has the newly combined hereditary traits of both parents. Thus, new grapevine varieties are created through targeted cross-breeding by sexual means. However, somatic mutations and vegetative propagation give rise to clone variants, mutants and chimeras.
Clone, mutant and clonal mutant
The three terms clone, mutant and clonal mutant are often used colloquially in viticulture to define the origin of a vine, but this is not correct, because a clone in the strict scientific sense is an identical copy of the original, while a clone in the viticultural sense is a mutated clonal variant and is no longer 100% identical to the original plant. In practice, clones of grapevine varieties are only addressed as clones when they can be at least slightly distinguished from the original type in some visible or measurable individual characteristics, i.e. they are already mutated. Such mutations occur spontaneously and often as bud mutations. Later, after budding, they are multiplied by vegetative propagation of the mutant shoots.
A clonal mutant is a clone (duplicate) of a variety that deviates in some characteristics. Clone mutants are produced by spontaneous mutation of a fruit shoot that has been selected for its deviating characteristics and further...
