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A landrace is a local variety of a domesticated animal or plant species which has developed over time, by adaptation to the natural and cultural environment in which it lives. Landraces are usually more genetically and physically diverse than formal breeds. Many formal breeds originated from attempts to make landraces more consistent through selective breeding, and sometimes a particular type has both landrace and formal breed populations. Sometimes a formalised breed retains a landrace name, despite no longer being a true landrace. When an animal landrace is codified as a pedigree breed without significant selective breeding to alter it, though often to lock in its defining traits, it is often referred to as a natural breed or traditional breed by breeder and fancier organisations. Similarly, the term traditional variety is sometimes applied to plant landraces, and heirloom plants may be samples of landraces.
Landraces are distinct from ancestral species of modern stock, and from separate species or subspecies derived from the same ancestor as modern domestic stock. Landraces are not all derived from ancient stock unmodified by human breeding interests. In a number of cases, most commonly dogs, domestic animals have reverted to "wild" status by escaping in sufficient numbers in an area to breed feral populations that, through evolutionary pressure, form new landraces in only a few centuries. Modern plant cultivars can also fairly quickly produce new landraces through undirected breeding.
"Landrace populations are often highly variable in appearance, but they are each identifiable morphologically and have a certain genetic integrity. Farmers usually give them local names. A landrace has particular properties or characteristics. Some are considered early maturing and some late. Each has a reputation for adaptation to particular soil types according to the traditional peasant soil classifications, e.g. heavy or light, warm or cold, dry or wet, strong or weak. They also may be classified according to expected usage; among cereals, different landraces are used for flour, for porridge, for 'bulgur', and for malt to make beer, etc. All components of the [plant] population are adapted to local climatic conditions, cultural practices, and disease and pests."
The term has been more recently characterized by A. C. Zeven in 1998:
"An autochthonous landrace is a variety with a high capacity to tolerate biotic and abiotic stress, resulting in a high yield stability and an intermediate yield level under a low input agricultural system."
The terms "landrace" and "traditional variety" are sometimes used interchangeably.
Landraces are grown from seeds which have not been systematically selected and marketed by seed companies or developed by plant breeders. Landraces refer to all those cultigens that are highly heterogeneous, but with enough characteristics in common to permit their recognition as a group.
This includes all cultigens cultivated without any specific nomenclature and value. A landrace identified with a unique feature and selected for uniformity over a period of time for maintenance of the characteristic features of the population can evolve into a farmers' variety or even a modern cultivar as in many crops; for example, Maruti in the case of pigeonpeas.
Conversely, a modern cultivar grown over time by the farmers and not maintained as per the principles of maintenance breeding can "evolve" into a landrace.
A significant proportion of the world's farmers grow landraces. Data collected for a study of the spread of cereal agriculture into Europe showed that landraces have largely fallen out of use in Europe. European cereal landraces were mainly grown by farmers before breeders started to improve the varieties in the 20th century.
Some landraces have survived in Europe, having been handed on from one generation of farmers to the next. Elsewhere, landraces and traditional varieties have been revived by enthusiasts who seek to preserve their agricultural and culinary heritage. Landraces and traditional varieties are valued for uses as diverse as ingredients in traditional food and drinks and as raw materials for thatching.
There have been systematic efforts to preserve European cereal landraces either in germplasm collections or in situ. The activities of these collections are coordinated by Bioversity International. This organisation coordinates information on conservation activities, including a searchable online database of germplasm collections. However, more needs to be done, Regine Anderson argues, because plant genetic variety depends on a diversity of landraces.[clarification needed]]]
Landraces occur in many species of domestic animals. A landrace does not imply so much a breed as a type of animal, though even "type" is not always synonymous. Often, from within a landrace a small number of animals have been carefully selected to found a formal pedigree breed, sometimes of the same name as the landrace. They may even have the capitalized word "Landrace" in their breed names. While they are standardised breeds derived from landraces, they are not entirely representative of the landraces from which they derive, and do not themselves constitute landraces. When people select animals to create a highly consistent purebred breed, they most often select for a consistent appearance, rather than behavior or adaptability to a given environment (indeed, "wild" behavior is usually intentionally bred out). When this happens, defining characteristics of the underlying actual landrace may be rapidly lost in the derived breed.
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Dog landraces and the selectively bred, formalized dog breeds derived from them vary greatly, depending on their origins and purpose. All dog types are essentially derived from the gray wolf. The process of how dogs were domesticated is best illustrated by the experiments undertaken by Dmitri Belyaev in the old Soviet Union with the silver fox, which eventually created the domesticated silver fox or by the genome-wide association studies of Elaine Ostrander at the NIH. The Border Collie breed is derived from a same-named landrace that is used as a herding dog and varies in appearance: ears pricked upright to nearly dropped, varied fullnesses of coat, and so on. However, they are recognised as Border Collies by their general appearance and most of all by their unique manner of herding sheep. In contrast to the landrace, in the Border Collie breed show-quality individuals very closely match a "breed standard" appearance but might not be particularly good at herding sheep and might not have a coat suitable for outdoor life. Similarly, the ancient landrace of the Middle East that led to the Saluki breed excels in running down game across open tracts of hot desert, but show-quality individuals of the breed might not be able to chase and catch hares in the desert. The now extinct St. John's water dog landrace was native to the island of Newfoundland. It was the foundational breed for a number of purpose-bred dogs, such as the Labrador Retriever, and Chesapeake Bay Retriever, as well as the Newfoundland. Another example of a North American landrace that developed from Asian dogs is the Carolina Dog (also called Yellow Dog, and which has also been established now as a formal breed). The mountain dog is more of a complex of similar and not always related breeds and landraces, and is the common working dog type of mountain environs of central Eurasia. An Old World canine landrace is the Armenian Gampr dog.
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Some formal, selective breeds that are derived from landraces include the Dutch, Swedish and Finnish Landrace Goats. The confusingly named Dutch Landrace is a modern mix of three different breeds, one of which was a landrace.
Although the term "landrace" is rarely used in modern horse breeding, numerous landraces of the domestic horse, Equus ferus caballus, do exist. Some of these are predominantly feral types, but the majority are fully domesticated working animals. Notable landraces from which pedigreed breeds have been formed include the New Forest pony and Exmoor pony. The New Forest mares living semi-wild in the New Forest are largely non-pedigreed landrace animals, while the stallions, and those kept as fully domesticated animals and bred for showing are a formal breed. Aficionados of some horse breeds claim them to be "pure" and virtually unchanged from their original wild prototype or landrace. Such breeds include the Arabian horse and the Andalusian horse, and a number of feral breeds (such as the Banker horse) that are restricted to islands. Przewalski's horse, E. f. przewalskii, has never been successfully domesticated and thus is a true wild horse, is a separate subspecies with a different number of chromosomes than domesticated equines, and thus is not a caballus landrace.
The formal breeds named "Landrace" are not actually landraces, and usually not even derived from one. The Danish Landrace, pedigreed in 1896 from the actual local landrace, is the principal ancestor of the so-called American Landrace (1930s). The Swedish Landrace is derived from the Danish and from other Scandinavian breeds, as was the misleadingly named British Landrace, which was established as late as 1950.