Dr.R.Kuralarasi, Assistant Professor Department of Biotechnology Ayya Nadar Janaki Ammal College, Sivakasi Tamilnadu India

1. Centers of origin of cultivated
crops
Dr. R. Kuralarasi
Assistant Professor
Department of Biotechnology
Ayya Nadar Janaki Ammal College
Sivakasi – 626 124

2. Centres of origin of cultivated
crops

3. Introduction:
Vavilov (1926, 1949-50), an outstanding plant
geographer and a renowned geneticist of the former
soviet union, undertook a detailed exploration of the
crop taxa in many less developed and largely
montane terrains of the world, considered by him
areas of ancient agricultural civilisation.
He believed that in these areas the indigenous crop
varieties would not yet have given rise to cultivars
selected by plant breeders.

4. Based on detailed study of the geographic distribution
of genetic diversity in various crop species, he
identified many areas as center of genetic diversity;
he also believed that the centres of great genetic
diversity are like wise the centres of origin of
cultivated plants.
He identified these centres on the bases of varietal
diversity, homologous variation, endemism,
dominant allele frequencies and disease
resistance and recognised eight centres of origin
of domesticated plants popularly called Vavilov
centres or germplasm treasures later (Khohsoo
1991).

5. The eight centres are
1. East Asia(Chinese centre)
2. Tropical Asia (Indian and Indo-Malayan centre)
3. South –west Asia (inner Asiatic centre)
4. The Near East (Asia Minor centre)
5. Mediterranean centre
6. Abyssinia centre
7. Andean centre and
8. Central America including Southern Mexico.

6. Vavilov centres of origin of cultivated
taxa and the most important
cultivated taxa belonging to them

7. 1.Chinese centre Millets, Sorghum, buck wheat,
soybean, kidney bean, yam, radish,
cannabis, tea (total cultivated taxa:
136).
2.(a) Indian centre
(b) indo-Malayan centre
Rice, Finger millet, Pigeon pea, Green
gram, Horse gram, Winged bean,
Cluster bean, Amaranthus sp., Brinjal,
Bitter gourd, Bottle gourd, Snake
gourd, Taro, Mango, Orange, Lemon,
Myrobalan, Breadfruit, Tamarind,
Sugar-cane , Mustard ( total: 117).
Coix, Velvet bean, Zinger, Pomelo,
Litchi, Banana, Durio, Coconut,
Cardamom, Black pepper, Turmeric,
Gutta-percha (total: 55).

8. 3. Inner Asiatic
centre
Peas, Lentils, Chick-pea, Flax, Safflower,
Melon, Carrot, Onion, Basil, Pistachio, Paer,
Grapevine(total: 55) .
4.Asia Minor Eincom type Wheat, Soft Wheat, Secabe,
Cereals, Pea, Alfalfa, Vetch, Sesame, Castor,
Figs, Poppy, Pumpkin(total:83).
5.Mediterranean
centre
Artichoke, emmer, oats, barley, lentils, horse
bean, chick-pea, flax, black mustard, olive,
beetroot, cabbage, Onion, Cumin, Fennel,
Lavender(total:84) .
6.Abyssinian
centre
Triticum durum, Barley, Finger millet, Lentil,
Fenugreek, Niger, Safflower, Sesame,
coriander, Coffee, Bhendi, Pearl millet,
Sorghum(total:38).

9. 7.South Mexican &
Central American
centre
Maize, Jack- bean, Squash, Chayote,
Pumpkin, Sweet potato, Pepper, Chilli, Upland
cotton, Sisal, Papaya, Guava, Cherry, Tomato,
Cocoa, Avocado(total:49).
8.(a) South
American (Peru,
Ecuador, Bolivia)
centre
(b)Chilean centre
(c)Brazil-Paraguay
centre
Potato, Lupine, Maize, Tomaato, Peanut,
Tobacco(total:45).
Strawberry(total:4).
Manihot, Peanut, Hevea rubber, Pineapple,
Yam, Cassava(total:13).

10. Vavilov concept underwent modifications due to very
interesting further work on those eight centres.
Harlan (1971, 1975 a) recognised that some Vavilov
centres do indeed fit the geographical concept of
centre's and non- centre's the latter covering vast
areas of very great physical and cultural
diversity. Thus he designated 12 areas in the
world, including Vavilov’s eight centres, as
domestication areas.

11. Areas of the world where plants were
domesticated along with the most common
domesticated taxa of these areas (after
Harlan 1976)

12. 1.North America Sunflower, Tepary bean
2.Mesoamerica Maize, Tomato, Cotton*, Avocado, Papaya,
Cocoa, Cassava* ,Sweet potato*, Common
bean*
3.Lowland South
America
Yam, Pineapple, Cassava*, Sweet potato*,
Cotton*
4.Highland South
America
Potato, Peanut, Lima bean, Cotton*, Bean*
5.Europe Oats, Sugar-beet, Rye, Cabbage, Grapes*,
Olive*
6. Africa Sorghum, Pearl millet, Yam, Watermelon,
Cowpea, Africa rice, Coffee, Cotton?*,
Sesame?*

13. 7. Near East Wheat, Barely, Onion, Pea, Lentil, Chick-pea, Fig,
Date, Flax, Pear, Pomegranate, Grapes*, Olive*,
Apple?
8.Central Asia Common millet, Buckwheat, Alfalfa, Hemp, Foxtail
millet*, Grapes*, Broad- bean?
9.India Pigeon-pea, Eggplant, Cucumber, Cotton*, Sesame*
10.China Soybean, Cabbage, Onion, Peach, Foxtail millet*
11.South-east
Asia
Oriental rice, Banana, Citrus, Yam, Mango, Sugar-
cane, Tea, Taro
12.South Pacific Sugar-cane, coconut, Breadfruit
*taxa that were probably domesticated independently in
different areas.

14. Harlan’s work showed that different species of the
same crop were different domesticated in places
and that independent domestication of the same
species of the crop occurred in different places and
at different times. Consequently one single centre
of origin cannot be identified for all crops.
The ‘centres of origin’ concept sometimes gives rise
to certain misconception because it ignores
phenomena such as Transdomestication
(Hymowitz 1972).

15. Dispersal and diversification
Man has played a very important role in the
diversification of gene pools of crop Plants.
Archaeological evidence from many parts of world
has shown that several cultivated spices have had a
fairly rapid spread through different parts of the world,
mainly through human activity. In all places where
they spread, they were subjected to modifications by
the prevailing local cultivation practices. Secondary /
tertiary centers of diversities evolved in those places
where further genetic differentiation was favored in
the crop plants.

16. Ethiopia, for example, become a secondary centre of crop
plant diversification for Middle East crops such as barley,
emmer wheat, peas, Lentil and many others, Latin
America formed secondary centers for beans, ground-nut,
maize, cassava and rubber and the Mediterranean for rye
and Oats.
During the Process of dispersal to and establishment in
places other than the centers of origin, crop plant genomes
underwent changes due to frequent or sporadic
recombination within primary gene pools (Harlan and de
wet 1971 and due to mutation or polyploidy that were
effected to confer resistance to parasites/predators or other
biotic or Abiotic stresses encountered in those places.

17. Diversity in Domesticated Species
The overall result of domestication was as follows:
As the number of cultivated species increased, the number
of wild species used for food (Flannery 1969) and other
purposes decreased. Of the 511 plant families currently
recognized (Brummitt 1992), only 173 have cultivated
representatives.
Of these 173 families, Poaceae has the largest number of
domesticated species-380 (15.2% of all domesticated
taxa), Leguminosae (sensu lato) follows with about 340
species (13.6%), Rosaceae ranks third with about 158
species (6.32%), followed by Solanaceae (155 species,
4.6%) Asteraceae (86 species, 3.44%), Cucurbitaceae
(53 species, 2.12%), Lamiaceae (52 species, 2.08%),
Rutaceae (44 species, 1.76%),

18. Rutaceae (44 species, 1.76%), Brassicaceae (43
species, 1.72%), Apiaceae (41 species, 1.64%),
Chenopodiaceae (34 species, 1.36%), Zingiberaceae
(31 species, 1.24%) and Arecaceae (30 species,
1.2%).
Many families, numbering about 50, have only one
domesticated species. Although the majority of
domesticated taxa are used as sources of food, some
were selected for domestication for their fibres
(cotton, hemp, flax etc.,).
Among the 25,000 plants believed to be useful/used in
various system of medicine, only a very few have

19. The number of cultivated taxa increased as a result of
diversification of human needs, only to be drastically
reduced in the last one hundred years. Of the 400,000 plants
species estimated and 300,00 species documented, 4000
species are edible. According to Mangelsdorf (1966), of
these early man used at least 3000 plants species as food,
but resorted to active cultivation of only 150-200 of them
(see Boyle and Lenne 1997).
Even among these, only 4 are major crop species (rice,
wheat, maize, and potato), providing for more than 50% of
the food requirements of people.
Thus the levels of genetic diversity of cultivated crop species
have been subjected to profound changes at the species
level from the time of their initial selection (i.e., in the pre
agricultural hunter-gatherer stage) up to about 100 years
ago.

20. Although the total number of species of domesticated crops
was reduced, efforts to increase the infraspecific diversity
within the selected species were well underway i.e., variation
within selected species increased immensely. For example,
there are an estimated 130,000 distinct varieties within the
rice species Oryza sativa (Chang 1995).
In the last two to three decades, due to modern scientific
breeding, there has been a very drastic reduction in use of
infraspecific variation as a result of human preferences, cost
of production, yield/performance potential, etc. there has
also been a drastic reduction in area cultivated for local
varieties, resulting very few elite varieties in each crop
possessing greater genetic vulnerability, defined as the
genetic constitution of crop. Such varieties are very uniform
and homogeneous and replace the vulnerable varieties. This
has substantially eroded the genetic the genetic diversity of
crop species. Certain specific examples will illustrate this
point.

21. Philippino farmers were using several hundreds of rice
varieties earlier, but in recent years two varieties alone
account 90% of the area planted (Friis-Hansen 1994;
NRC 1993).
In Argentina local varieties of Amaranthus have been
almost totally replaced by modern varieties; in China, of
the 10,000 wheat varieties used in 1949, only 1000
were use by 1975; and in Sri Lanka, of the 2000 rice
varieties in 1959, only five are presently cultivated (see
Virchow 1998).
In the USA, of the 7098 apple varieties documented in
the US Department of Agriculture as having been use
up to 1904, approximately 86% have been lost. Similar

22. The extinction rates of vegetable varieties of asparagus,
beets, onions and others in the USA between 1903 and
1983 ranged between 87 and 98% (Fowler and Mooney
1990)
The present-day plant diversity of each crop thus ranges at
the evolutionary level from wild ancestors (as in oil palm)
to very advanced cultivars (as in wheat); at the ecological
level, from components of a ‘primeval ecosystem to those
of high-input agriculture and horticulture’; and at the
genetic level, ‘from population to genes’ (Frankel et al.
1995). A functional classification of crop plant germplasms
(or genetic resources) into the following categories was
introduced by the International Biological Programme
(IBP 1966; see also Frankel and Bennett 1970): Land
races, Advanced cultivars, Wild species used by man. To
these Frankel et al. (1995) have added Genetic stocks
and Cloned Genes.