Variety (plant)

from Wikipedia, the free encyclopedia
This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

A variety of a plant is a term from plant breeding that distinguishes variants of an ornamental or useful plant species. The variety must differ from other varieties of the same species by different characteristics (size, color, quantity and pattern) . The equivalent of the term in animal husbandry is breed .

According to the definition of the International Code of Nomenclature of Cultivated Plants (2009), a cultivar is a set (assemblage) of plants that a) have been selected for one property or a combination of several properties, b) different [from other plants] with regard to these properties, is uniform and stable and c) retains these properties when propagated appropriately (Article 2.3). It does not depend on a certain type of origin and propagation (Article 2.4). Many plant varieties correspond to such cultivars. But there are also quite a few plant varieties that are not cultivars, especially the hybrid varieties that are economically very important today are not among them.

The relationship to a biological species or other ranks of the botanical taxonomy (for example in the case of hybrids ) does not follow the nomenclature rules set out in the International Code of Nomenclature for Algae, Fungi and Plants ICBN. A variety can sometimes correspond to a certain rank of the ICBN, for example a variety, but usually none of them; the only important thing is that it has constant characteristics. The ancestral form of our cultivars are usually other cultivars that ultimately go back to one or (less often) several domestication events in which wild plants were first cultivated . From this, through conscious or unconscious breeding selection, so-called local varieties emerge . A distinction is made between horticulture , field cultivation , viticulture and silviculture, cultivar or noble variety , wild variety , wildlings . A “wild variety” corresponds to a group of wild-growing individuals from the original form, which are selected and selected for breeding purposes and then crossed back into the cultivated variety.

The term variety goes back to forms of agricultural organization in which different variants of a plant species whose seeds or cuttings were stored separately (sorted) in order to be able to cultivate them in pure culture. The subsequent separation of stored seeds of different varieties is usually not possible.

Cultivars

Cultivars are homozygous or refined varieties that man has cultivated in the long history of plant breeding from found wild varieties. Recently, however, there are also genetically modified organisms in the sense of a cultivar, which in practice are still closely based on a "natural" plant due to the limited possibilities. From a practical point of view, all cultivars are changed in their genetic expression ( genotype ) by humans , albeit with purely breeding methods.

Seeds of a cultivated variety are subjected to a test of the characteristics, receive a variety approval , are entered in a - national as well as EU-wide - variety list in order to be allowed to be cultivated or traded and then also receive variety protection . Varieties of ornamental plants ( flowers , ornamental trees ) are not subject to this restriction .

When it comes to fruit and vegetables , the variety of fruit and vegetable varieties plays an important role, especially with apples and potatoes . The same applies to types of lettuce , because various lettuce plants are summarized under the collective term "lettuce" , e.g. B. Garden salad ( Lactuca ), lamb's lettuce ( Valerianella ) and many others.

Wild varieties

Wild varieties are varieties of wild plants that occur freely in nature . They form the stem of the types of fruit cultivated today.

Examples:

Wildlings

Wildlings are again overgrown forms of cultivated plants, both as single specimens and as wild plants, which build up a stable population and mostly revert to the more robust appearance of the original stem form, but also develop their own stable subspecies.

Examples:

  • Real medlar ( Mespilus germanica ), a plant that grew wild in Central Europe from Roman cultivation, whose original home is in the Middle East and which therefore has a misleading botanical name
  • Jerusalem artichoke ( Helianthus tuberosus ), a sunflower from South America that is used as a cultivated plant like a potato. It turns wild into an annoying neophyte and also changes its appearance ( growth form ) significantly
  • In silviculture , wildlings are young wild plants from natural regeneration

Variety firmness

Plant varieties that do not lose their varietal characteristics through seed production and new planting are called varietal -fixed . Newer plant breeding methods, however, usually lead to non-varietal plants. Here the variety characteristics are mostly lost, the desired characteristics are then only found in the first daughter generation ( F 1 generation ). If such varieties are nevertheless used for seed production and re-sowing, the characteristics of the variety split up. So the seeds cannot be reproduced .

Problem of demarcation

The stem shape of many, especially traditional plants, is unknown, for example typically the cultivated apple ( Malus domestica ), of which the European crab apple ( Malus sylvestris ) was assumed to be the ancestor for a long time . However, recent research suggests other wild apples as ancestors, such as the Asian wild apple ( Malus sieversii ). Sometimes the existence of a separate species Malus sylvestris is questioned or its extinction is considered possible, as the genetic proximity of the crab apple trees still present in Europe to the cultivated apple is explained by the fact that they could be mixed breeds or wildlings.

While plant breeding has always relied on empirical values ​​about genetic compatibility, the classification of the classical biological taxonomy was primarily based on phenomenological aspects. For example, the (sweet) cherry is a pure variety of the bird cherry ( Prunus avium ), which is only propagated vegetatively, but plum varieties ( Prunus domestica ) have mostly been genetically cultivated since they were hybridized. An apple variety refined on a breeding base is botanically not a hybrid, but a chimera , a noble pear ( Pirus ) grown on a quince base ( Cydonia ) even across genus boundaries.

Importance of wild forms for plant breeding

Many problems of modern fruit growing can be traced back to the genetic poverty of the modern cultivars caused by the long history of breeding, such as a lack of adaptability to changed living conditions or pests . Finding the original stem forms in order to enrich the gene pool again is the subject of modern research. Typical examples of this are the search for the wild forms of tomatoes , maize and potatoes in the highland areas of the Andes . Here, too, it is aggravating that it is usually not known whether the wild variety has not already become extinct, as is the taxonomic survey, which is still very incomplete for many parts of the world.

Plant variety protection

The plant variety certifies the intellectual property of biological organisms. It is regulated in the international UPOV agreement, which has also been implemented in the EU and Germany ( Plant Variety Protection Act ). After successful variety testing by the Bundessortenamt , the applicant receives an exclusive right to the variety which only allows him or his legal successor to use the variety commercially in the form of propagation material (plants, plant parts including seeds) ( list of varieties ). Plant variety protection ends after 30 years at the latest and cannot be extended.

Individual evidence

  1. ↑ Regine Filler, Protection of Biological Organisms

Web links

Wiktionary: variety  - explanations of meanings, word origins, synonyms, translations