Crop wild relative

Crop wild relative
A crop wild relative (CWR) is a wild plant closely related to a domesticated plant. It may be a wild ancestor of the domesticated (cultivated) plant or another closely related taxon.
Overview
The wild relatives of crop plants constitute an increasingly important resource for improving agricultural production and for maintaining sustainable agro-ecosystems. Their natural selection in the wild accumulates a rich set of useful traits that can be introduced into crop plants by crossing. With the advent of anthropogenic climate change and greater ecosystem instability CWRs are likely to prove a critical resource in ensuring food security for the new millennium. It was Nikolai Vavilov, the Russian botanist who first realized the importance of crop wild relatives in the early 20th century. Genetic material from CWRs has been utilized by humans for thousands of years to improve the quality and yield of crops. Farmers have used traditional breeding methods for millennia, wild maize (Zea mexicana) is routinely grown alongside maize to promote natural crossing and improve yields. More recently, plant breeders have utilised CWR genes to improve a wide range of crops like rice (Oryza sativa), tomato (Solanum lycopersicum) and grain legumes.
CWRs have contributed many useful genes to crop plants, and modern varieties of most major crops now contain genes from their wild relatives. Therefore, CWRs are wild plants related to socio-economically important species including food, fodder and forage crops, medicinal plants, condiments, ornamental, and forestry species, as well as plants used for industrial purposes, such as oils and fibres, and to which they can contribute beneficial traits. A CWR can be defined as "... a wild plant taxon that has an indirect use derived from its relatively close genetic relationship to a crop...”
Conservation of crop wild relatives
CWRs are essential components of natural and agricultural ecosystems and hence are indispensable for maintaining ecosystem health. Their conservation and sustainable use is very important for improving agricultural production, increasing food security, and maintaining a healthy environment.
The natural populations of many CWRs are increasingly at risk. They are threatened by habitat loss through the destruction and degradation of natural environment or their conversion to other uses. Deforestation is leading to the loss of many populations of important wild relatives of fruit, nut, and industrial crops. Populations of wild relatives of cereal crops that occur in arid or semi-arid lands are being severely reduced by over grazing and resulting desertification. The growing industrialization of agriculture is drastically reducing the occurrence of CWRs within the traditional agro-ecosystems. The wise conservation and use of CWRs are essential elements for increasing food security, eliminating poverty, and maintaining the environment.
Conservation strategies for CWRs often consider both in situ and ex situ conservation. These are complementary approaches to CWR conservation, since each has its own advantages and disadvantages. For example, whilst ex situ conservation protects CWR (or more correctly, their genes) from threats in the wild, it can limit evolution and adaptation to new environmental challenges.
In 2016, 29% of wild relative plant species were completely missing from the world’s genebanks, with a further 24% represented by fewer than 10 samples. Over 70% of all crop wild relative species worldwide were in urgent need of further collecting to improve their representation in genebanks, and over 95% were insufficiently represented with regard to the full range of geographic and ecological variation in their native distributions. While the most critical priorities for further collecting were found in the Mediterranean and Near East, Western and Southern Europe, Southeast and East Asia, and South America, crop wild relatives insufficiently represented in genebanks are distributed across almost all countries worldwide.
Examples of wild relatives
Grains
Oats (Avena sativa) – Avena byzantina
Quinoa (Chenopodium quinoa) – Chenopodium berlandieri
Finger Millet (Eleusine coracana) – Eleusine africana
Barley (Hordeum vulgare) – Hordeum arizonicum and Hordeum spontaneum
Rice (Oryza sativa) – Oryza rufipogon
African Rice (Oryza glaberrima) – Oryza barthii
Pearl Millet (Pennisetum glaucum) – Pennisetum purpureum
Rye (Secale cereale subsp. cereale) – Secale cereale subsp. dighoricum
Sorghum (Sorghum bicolor) – Sorghum arundinaceum and Sorghum halepense
Broom millet (Panicum miliaceum) – Panicum fauriei
Wheat (Triticum aestivum) – Einkorn wheat (Triticum monococcum)
Maize (Zea mays subsp. mays) – Zea diploperennis
Vegetables
Note: Many different vegetables share one common ancestor, particularly in the Brassica genus of plants (cruciferous vegetables). Many vegetables are also hybrids of different species, again this is particularly true of Brassicas (see e.g. triangle of U).
Asparagus (Asparagus officinalis) – Asparagus dauricus
Beet (Beta vulgaris subsp. vulgaris) – Beta vulgaris subsp. maritima
Black Mustard (Brassica nigra) – Wild mustard (Sinapis arvensis)
Cabbage (Brassica oleracea var. capitata) - Brassica elongata
Carrot (Daucus carota) – Daucus gracilis
Garlic (Allium sativum var. sativum) – Allium atroviolaceum
Leek (Allium ampeloprasum) – Welsh onion (Allium fistulosum)
Lettuce (Lactuca sativa) – Prickly lettuce (Lactuca serriola)
Mustard (Brassica juncea subsp. juncea) – Brassica carinata
Onion (Allium cepa var. cepa) – Allium galanthum
Rape (Brassica napus var. napus) – Common dogmustard (Erucastrum gallicum)
Spinach (Spinacea oleracea) – Spinacia turkestanica
Squash (Cucurbita pepo subsp. pepo) – Cucurbita okeechobeensis
Turnip (Brassica rapa subsp. rapa) – Brassica rapa
Fruits
Almond (Prunus dulcis) – Chinese plum (Prunus salicina and many others)
Apple (Malus domestica) – mostly Malus sieversii, but with some cultivars perhaps belonging to Malus sylvestris or being a hybrid of the two.
Apricot (Prunus armeniaca) – Prunus brigantina
Avocado (Persea americana) – Persea schiedeana
Banana – Musa acuminata, Musa balbisiana and Musa schizocarpa
Breadfruit (Artocarpus altilis) – Jackfruit (Artocarpus heterphyllus)
Cacao (Theobroma cacao) – Theobroma angustifolium
Cherry (Prunus avium) – Prunus mahaleb
Cucumber (Cucumis sativus) – Cucumis hystrix
Eggplant (Solanum melongena) – Thorn apple (Solanum incanum), Solanum insanum
Grape (Vitis vinifera) – European wild grape (Vitis sylvestris). Hybrids exist also including other Vitis species.
Grapefruit (Citrus paradisi) – Citrus medica
Lemon (Citrus limon) – Citrus indica
Mango (Mangifera indica) – Mangifera altissima
Orange (Citrus sinensis) – Key lime (Citrus aurantiifolia)
Papaya (Carica papaya) – Jarilla chocola
Peach (Prunus persica var. persica) – Prunus tomentosa
Pear (Pyrus communis) – Pyrus pyraster and Pyrus caucasica
Pepper (Capsicum annuum) – Capsicum baccatum
Pineapple (Ananas comosus) – Ananas bracteatus
Plum (Prunus domesticus subsp. domestica)- Prunus spinosa and Prunus cerasifera
Pumpkin (Cucurbita maxima subsp. maxima) – Cucurbita ecuadorensis
Strawberry (Fragaria× ananassa)
Tomato (Solanum lycopersicum) – Solanum chilense
Watermelon (Citrullus lanatus var. lanatus) – Bitter apple (Citrullus colocynthis)
Oilseeds
Peanut (Arachis hypogaea subsp. hypogaea) – Arachis duranensis
Sunflower (Helianthus annuus) – Helianthus exilis
Soya (Glycine max) – Glycine clandestina
Safflower (Carthamus tinctorius) – Carthamus creticus
Rapeseed (Brassica napus) – Brassica rapa, Brassica oleracea
Pulses
Lentil (Lens culinaris) – Lens ervoides
Garden Pea (Pisum sativum) – Pisum fulvum
Butter Bean (Phaseolus lunatus) – Phaseolus augusti
Garden Bean (Phaseolus vulgaris) – Phaseolus coccineus
Faba Bean (Vicia faba) – Vicia johannis
Grasspea (Lathyrus sativus) – Lathyrus tuberosus
Cowpea (Vigna unguiculata) – Vigna monantha
Bambara groundnut (Vigna subterranea) – Vigna hosei
Pigeonpea (Cajanus cajan) – Cajanus albicans, Cajanus scarabaeoides, Cajanus sericeus, Cajanus acutifolius
Chickpea (Cicer arietinum) – Cicer reticulatum, Cicer echinospermum
Vetch (Vicia sativa) – Vicia barbazitae
Adzuki bean (Vigna angularis var. angularis) – Vigna umbellata
Black gram bean (Vigna mungo var. mungo) – Vigna grandiflora
Mung bean (Vigna radiata var. radiata) – Vigna stipulacea
Forages
Alfalfa (Medicago sativa) - Medicago arborea and Medicago truncatula
Tubers
Sweet potato (Ipomoea batatas) – Ipomoea triloba, Ipomoea cynanchifolia, Ipomoea leucantha and Ipomoea trifida
Cassava (Manihot esculenta subsp. esculenta) – Manihot walkerae
Potato (Solanum tuberosum) – Solanum chacoense
See also
List of domesticated plants
Wild type
Agricultural biodiversity
Agriculture
Agronomy
Gene pool
Australian Grains Genebank
Plant genetic resources
References
External links
Crop Wild Relatives Inventory and Gap Analysis
European Crop Wild Relative Diversity Assessment and Conservation Forum
Beyond the Gardens: The Crop Wild Relatives Project (Vimeo Video)
A short video on emmer wheat.
Short DIVERSEEDS video on crop wild relatives in the fertile crescent in Israel
Atlas of Guatemalan Crop Wild Relatives
Bioversity International - Crop Wild Relatives
Agroecology
Crops
Habitat management equipment and methods