Center of origin and diversity

Introduction

A center of origin, also known as a center of diversity, is a specific geographical location where a group of organisms, whether domesticated or wild, first exhibited their unique characteristics. These areas are recognized as centers of diversity as well. The concept of centers of origin was first introduced by Nikolai Vavilov in 1924.

There is substantial evidence indicating that cultivated plants were not evenly distributed across the globe. Even in contemporary times, certain regions display significantly greater diversity compared to others regarding specific cultivated crops and their wild relatives. N.I. Vavilov suggested that crop plants evolved from wild species in regions characterized by high diversity, which he designated as primary centers of origin. Subsequently, crops were transported to other regions primarily due to human activities. These latter areas typically lack the variety found in the primary centers of origin. However, in some regions, certain crop species exhibit notable diversity in forms, even though they did not originate there. Such regions are classified as secondary centers of origin for these species.

Objectives

• To gain a comprehensive understanding of centers of origin and diversity

• To identify various centers of origin and the crops that originated from those locations

• To explore the life history of N.I. Vavilov

• To establish connections between centers of origin and centers of diversity

Fig. Vavilov, father of the centre of origin

Into the life of Vavilov

Vavilov was born into a merchant family in Moscow and was the elder brother of the distinguished physicist Sergey Ivanovich Vavilov. As the son of a Moscow merchant who had grown up in a poor rural village afflicted by persistent crop failures and food shortages, Vavilov developed a deep-seated passion from a young age for eradicating famine in both his homeland of Russia and globally.

He completed his studies at the Moscow Agricultural Institute in 1910, presenting a dissertation focused on snails as agricultural pests. Between 1911 and 1912, he was employed at the Bureau for Applied Botany and the Bureau of Mycology.

Subsequently, in 1935, Vavilov established a new center of origin known as the U.S.A. Center of Origin. Two plant species, namely the sunflower and the Jerusalem artichoke, are believed to have originated from this U.S.A. center of origin.

Fig. Vavilov centre of origin

World centers of origin of cultivated plants

1) South Mexican and Central American Center 

• Encompasses the southern regions of Mexico, Guatemala, Honduras, and Costa Rica.

• Grains and Legumes: maize, common bean, lima bean, tepary bean, jack bean, grain amaranth

• Melon Plants: malabar gourd, winter pumpkin, chayote

• Fiber Plants: upland cotton, bourbon cotton, henequen (sisal)

• Miscellaneous: sweetpotato, arrowroot, pepper, papaya, guava, cashew, wild black cherry, cochineal, cherry tomato, cacao.

2) South American Center 

•  62 plants identified; three subcenters

• 2) Peruvian, Ecuadorean, Bolivian Center:

• Root Tubers: Andean potato, other endemic cultivated potato species. Fourteen or more species with chromosome counts ranging from 24 to 60, edible nasturtium

• Grains and Legumes: starchy maize, lima bean, common bean

• Root Tubers: edible canna, potato

• Vegetable Crops: pepino, tomato, ground cherry, pumpkin, pepper

• Fiber Plants: Egyptian cotton

• Fruit and Miscellaneous: cocoa, passion flower, guava, heilborn, quinine tree, tobacco, cherimoya, coca

• 2A) Chiloe Center (Island off the southern coast of Chile)

• Common potato (48 chromosomes), Chilean strawberry

• 2B) Brazilian-Paraguayan Center

• manioc, peanut, rubber tree, pineapple, Brazil nut, cashew, Erva-mate, purple granadilla.

3) Mediterranean Center 

• Covers the regions bordering the Mediterranean Sea. 84 plants listed

• Cereals and Legumes: durum wheat, emmer, Polish wheat, spelt, Mediterranean oats, sand oats, canarygrass, grass pea, pea, lupine

• Forage Plants: Egyptian clover, white clover, crimson clover, serradella

• Oil and Fiber Plants: flax, rape, black mustard, olive

• Vegetables: garden beet, cabbage, turnip, lettuce, asparagus, celery, chicory, parsnip, rhubarb,

• Ethereal Oil and Spice Plants: caraway, anise, thyme, peppermint, sage, hop.

4) Asia Minor  

•  Encompasses the interior regions of Asia Minor, all of Transcaucasia, Iran, and the highlands of Turkmenistan. 83 species

•  Grains and Legumes: einkorn wheat, durum wheat, poulard wheat, common wheat, oriental wheat, Persian wheat, two-row barley, rye, Mediterranean oats, common oats, lentil, lupine

•  Forage Plants: alfalfa, Persian clover, fenugreek, vetch, hairy vetch

•  Fruits: fig, pomegranate, apple, pear, quince, cherry, hawthorn.

5) Abyssinian  

•  Comprises Abyssinia, Eritrea, and a portion of Somalia. 38 species are documented; abundant in wheat and barley.

•  Grains and Legumes: Abyssinian hard wheat, poulard wheat, emmer, Polish wheat, barley, grain sorghum, pearl millet, African millet, cowpea, flax, teff

•  Miscellaneous: sesame, castor bean, garden cress, coffee, okra, myrrh, indigo, enset.

6) Central Asiatic Center  

•  Covers Northwest India (Punjab, Northwest Frontier Provinces, and Kashmir), Afghanistan, Tajikistan, Uzbekistan, and western Tian-Shan. 43 plants

•  Grains and Legumes: common wheat, club wheat, shot wheat, peas, lentil, horse bean, chickpea, mung bean, mustard, flax, sesame

•  Fiber Plants: hemp, cotton

•  Vegetables: onion, garlic, spinach, carrot

•  Fruits: pistachio, pear, almond, grape, apple.

7) Hindustan Center

• Two subcenters

• 7) Indo-Burma: Main Center (India): Encompasses Assam, Bangladesh, and Burma, excluding Northwest India, Punjab, and Northwest Frontier Provinces, with 117 plant species

• Cereals and Legumes: chickpea, pigeon pea, urd bean, mung bean, rice bean, cowpea,

• Vegetables and Tubers: eggplant, cucumber, radish, taro, yam

• Fruits: mango, tangerine, citron, tamarind

• Sugar, Oil, and Fiber Plants: sugar cane, coconut palm, sesame, safflower, tree cotton, oriental cotton, jute, crotalaria, kenaf

• Spices, Stimulants, Dyes, and Miscellaneous: hemp, black pepper, gum arabic, sandalwood, indigo, cinnamon tree, croton, bamboo, turmeric,

• 7A) Siam-Malaya-Java: also known as the Indo-Malayan Center: Covers Indo-China and the Malay Archipelago, with 55 plant species

• Cereals and Legumes: Job's tears, velvet bean

• Fruits: pummelo, banana, breadfruit, mangosteen

• Oil, Sugar, Spice, and Fiber Plants: candlenut, coconut palm, sugarcane, clove, nutmeg, black pepper, manila hemp.

8) Chinese Center

• A total of 136 endemic plant species are documented in the largest independent center

• Cereals and Legumes: for instance, rice, broomcorn millet, Italian millet, Japanese barnyard millet, sorghum, buckwheat, hull-less barley, soybean, Adzuki bean, velvet bean

• Roots, Tubers, and Vegetables: for example, Chinese yams, radish, Chinese cabbage, onion, and cucumber

• Fruits and Nuts: for instance, pear, Chinese apple, peach, apricot, cherry, walnut, litchi, orange

• Sugar, Drug, and Fiber Plants: for example, sugar, opium poppy, ginseng, camphor, hemp.

Conclusion

The notion that centers of diversity equate to centers of origin has been subjected to significant scrutiny. Plants belonging to a species that thrive in various environments are likely to exhibit differences, that is, diversity. Consequently, a species is expected to demonstrate greater variation in regions characterized by diverse climatic and ecological conditions. Areas featuring mountains and valleys present considerable environmental variation. Therefore, plant species are likely to display greater variation in such mountainous and valley regions. Moreover, the centers of diversity for numerous species have evolved over time. This evolution in diversity has been influenced by changes in the regions of extensive cultivation and the introduction of species into areas with heightened ecological diversity. These dynamics have led to the emergence of secondary centers of diversity. As a result, several species may possess two or more centers of diversity, making it challenging to ascertain which one is the authentic center of origin.

Thus, the term center of origin may be more accurately referred to as the center of diversity. These centers may not necessarily represent the original centers of the species in question, but they do signify the regions of maximum diversity for these species. This information serves as an invaluable resource for plant explorers seeking to identify variations within a specific species. Within the expansive centers of diversity, smaller regions may demonstrate significantly greater diversity than the centers themselves. These smaller regions are referred to as microcenters. The evolution of crops appears to advance at a more accelerated pace within these microcenters. Microcenters are crucial for plant collection and for conducting experimental studies on plant evolution.

References
• Candolle, A. De (1886). Origin of Cultivated Plants. New York: Appleton.
• Crow, J.F. (1993). N.I. Vavilov, Martyr to Genetic Truth. Genetics, 134(1):1-4. http://www.ncbi.nlm. nih.gov/pmc/articles/PMC1205417/. Accessed January 10th, 2013.
• Dorofeyev, V.F., Filatenko, A.A. (1992). Preface in Vavilov N. I., Origin and Geography of Cultivated Plants.  Translation by Doris Love. London: Cambridge University Press.
• Harlan, J.R. (1971). Agricultural Origins: Centers and Noncenters. Science, 174: 468-474.
• Ebeling, W. (1979). The Fruited Plain. The Story of American Agriculture. Berkeley: University of California Press.
• Oryza sativa. Proceedings of The National Academy of Sciences of the USA, 103 (25): 9578-9585. Loskutov, I.G. (1999). Vavilov and His Institute. A History of the World Collection of Plant Genetic Resources in Russia. Rome: IPGR.
• Pringle, P. (2008). The Murder of Nikolai Vavilov: The Story of Stalin’s Persecution of One of the Great Scientists of the Twentieth Century. New York: Simon & Schuster.
• Vavilov, N.I. (1997). Origin and Geography of Cultivated Plants. St. Petersburg: VIR.
• Zohary, D., & Hopf, M. (1993). Domestication of Plants in the Old World. The Origin and Spread of Cultivated Plants in West Asia, Europe, and the Nile Valley. Oxford: Clarendon Press.
• Shumnyĭ, V. K. (2007). "Two brilliant generalizations of Nikolai Ivanovich Vavilov (for the 120th anniversary)". Genetika. 43 (11): 1447–1453.
• Cohen, B. M. (1991). "Nikolai Ivanovich Vavilov: The explorer and plant collector a". Economic Botany. 45: 38–46. doi:10.1007/BF02860048
• Zakharov, I. A. (2005). "Nikolai I Vavilov (1887–1943)". Journal of Biosciences. 30 (3): 299–301. doi:10.1007/BF02703666
• Pringle, Peter (2008). The Murder of Nikolai Vavilov. Simon & Schuster. p. 300. ISBN 978-0-7432-6498-3.
• Ladizinsky, G. (1998). Plant Evolution under Domestication. The Netherlands: Kluwer Academic Publishers
• Vavilov, N. I.; Löve, Doris (trans.) (1992). Origin and Geography of Cultivated Plants. Cambridge University Press. p. xxi. ISBN 978-0521404273.
• Corinto, Gian Luigi (2014). "Nikolai Vavilov's Centers of Origin of Cultivated Plants With a View to Conserving Agricultural Biodiversity". Human Evolution. 29 (4): 285–301.
• Khoury, C.K.; Achicanoy, H.A.; Bjorkman, A.D.; Navarro-Racines, C.; Guarino, L.; Flores-Palacios, X.; Engels, J.M.M.; Wiersema, J.H.; Dempewolf, H.; Sotelo, S.; Ramírez-Villegas, J.; Castañeda-Álvarez, N.P.; Fowler, C.; Jarvis, A.; Rieseberg, L.H.; Struik, P.C. (2016). "Origins of food crops connect countries worldwide". Proc. R. Soc. B. 283 (1832): 20160792. doi:10.1098/rspb . 2016.0792