Introduction

The centres of origin are geographical areas where plants were first domesticated and cultivated. These regions are rich in genetic diversity, making them essential for breeding programs and the improvement of modern crop varieties. This concept was first systematically studied and developed by Nikolai Vavilov, a Russian botanist and geneticist, in the early 20th century.

Vavilov’s work emphasized that understanding the origin of crops could help identify their wild relatives, which serve as a source of useful traits like disease resistance, stress tolerance, and improved productivity.

Concepts Related to Centres of Origin

1. Centre of Origin: The area where a plant species was first domesticated from its wild ancestors.
2. Centre of Diversity: A region where a high degree of genetic variation in cultivated plants and their wild relatives exists, which may not necessarily be the same as the centre of origin.
3. Primary and Secondary Centres:
   • Primary Centre: The region where the crop originated.
   • Secondary Centre: Regions outside the primary centre where the crop has been grown for a long time, leading to additional diversity.

Nikolai Vavilov’s Contribution

Vavilov identified 8 major centres of origin for cultivated plants by conducting extensive fieldwork across various countries. He proposed that:

• Centres of origin are regions with the highest morphological and genetic diversity in crops.
• Wild relatives of crops are commonly found in these areas, providing evidence of their domestication history.

Importance of Centres of Origin

1. Genetic Resources for Breeding:
   • Provide genes for resistance to diseases, pests, and environmental stresses.
   • Example: Wild relatives of rice (Oryza rufipogon) in Asia contribute genes for drought and flood tolerance.
2. Food Security:
   • The diversity found in these centres ensures adaptability and resilience of crops to changing climates.
3. Preservation of Biodiversity:
   • Centres of origin serve as natural gene banks, safeguarding the genetic material for future agricultural use.

Vavilov’s Eight Centres of Origin

Here are the centres of origin identified by Vavilov, along with examples of crops:

1. Chinese Centre

• Location: Central and Western China.
• Crops:
  • Cereals: Rice (Oryza sativa), foxtail millet (Setaria italica).
  • Legumes: Soybean (Glycine max).
  • Fruits: Peach (Prunus persica), apricot (Prunus armeniaca).
  • Other Crops: Tea (Camellia sinensis), bamboo.
• Significance: Oldest centre for rice and soybean cultivation.

2. Indian Centre

• Location: India and parts of Burma (Myanmar).
• Crops:
  • Cereals: Pearl millet (Pennisetum glaucum), sorghum (Sorghum bicolor).
  • Legumes: Black gram (Vigna mungo), pigeon pea (Cajanus cajan).
  • Fruits: Mango (Mangifera indica), banana (Musa spp.).
  • Spices: Turmeric (Curcuma longa), ginger (Zingiber officinale).
• Significance: Rich in tropical fruits, legumes, and spices diversity.

3. Central Asiatic Centre

• Location: Afghanistan, Turkestan, and neighboring areas.
• Crops:
  • Fruits: Apple (Malus domestica), pear (Pyrus spp.), cherry (Prunus avium).
  • Vegetables: Onion (Allium cepa), garlic (Allium sativum).
  • Oilseeds: Flax (Linum usitatissimum).
• Significance: Primary centre for temperate fruits and vegetables.

4. Near Eastern Centre (Fertile Crescent)

• Location: Modern-day Iraq, Syria, Lebanon, Israel, and Jordan.
• Crops:
  • Cereals: Wheat (Triticum spp.), barley (Hordeum vulgare).
  • Legumes: Chickpea (Cicer arietinum), lentil (Lens culinaris).
  • Fruits: Fig (Ficus carica), pomegranate (Punica granatum).
• Significance: Known as the cradle of agriculture, it is the site of early domestication of cereals and pulses.

5. Mediterranean Centre

• Location: Mediterranean Basin (Southern Europe, North Africa, and Western Asia).
• Crops:
  • Vegetables: Cabbage (Brassica oleracea), lettuce (Lactuca sativa).
  • Fruits: Olive (Olea europaea), grape (Vitis vinifera).
  • Cereals: Oats (Avena sativa).
• Significance: Centre of diversity for olives and grapes, key to the Mediterranean diet.

6. Ethiopian Centre

• Location: Ethiopia and parts of East Africa.
• Crops:
  • Cereals: Sorghum (Sorghum bicolor), finger millet (Eleusine coracana), teff (Eragrostis tef).
  • Beverages: Coffee (Coffea arabica).
• Significance: Known for coffee and drought-resistant crops like teff.

7. Central American Centre

• Location: Mexico, Guatemala, and surrounding regions.
• Crops:
  • Cereals: Maize (Zea mays).
  • Legumes: Common bean (Phaseolus vulgaris).
  • Vegetables: Chili peppers (Capsicum spp.), squash (Cucurbita spp.).
• Significance: Domestication of maize, one of the most widely grown crops globally.

8. South American Centre (Andean Region)

• Location: Andes Mountains (Peru, Bolivia, Ecuador).
• Crops:
  • Tubers: Potato (Solanum tuberosum), sweet potato (Ipomoea batatas).
  • Grains: Quinoa (Chenopodium quinoa).
  • Fruits: Tomato (Solanum lycopersicum), pineapple (Ananas comosus).
• Significance: The centre for tubers and pseudocereals.

Center of Diversity

• Centre of Diversity: A region with the maximum genetic variability for a crop or its wild relatives.
• It serves as a natural gene bank, offering diverse traits for use in crop improvement programs.

Concept of Diversity

• Centres of diversity are not always synonymous with centres of origin.
• Example: Potato originated in the Andes but shows significant diversity in regions like Mexico, indicating a secondary centre of diversity.
• These regions include wild relatives, landraces, and domesticated varieties of plants.

Importance of Centres of Diversity

1. Genetic Resources for Plant Breeding:
   • Provide traits for disease resistance, stress tolerance, and adaptability.
   • Example: Wild Oryza species in Asia for improving rice.
2. Conservation of Biodiversity:
   • Preserve rare and unique alleles crucial for the future of agriculture.
3. Adaptation to Climate Change:
   • Diversity allows for selection of traits suitable for evolving climatic conditions.
4. Domestication Research:
   • Helps understand the evolutionary processes and domestication pathways of crops.

Difference Between Centres of Origin and Centres of Diversity

Examples of Centres of Diversity

1. Rice (Oryza sativa)

• Primary Centre of Diversity: South and Southeast Asia.
• Diverse Traits: Drought tolerance, disease resistance, high yield potential.

2. Wheat (Triticum spp.)

• Primary Centre of Diversity: Fertile Crescent.
• Secondary Centres: Europe, Central Asia.

3. Maize (Zea mays)

• Primary Centre: Mesoamerica (Mexico).
• Secondary Centre of Diversity: Southern U.S. and Andean region.

4. Potato (Solanum tuberosum)

• Primary Centre: Andes Mountains (Peru, Bolivia, Ecuador).
• Secondary Centre of Diversity: Mexico and parts of Europe.

5. Banana (Musa spp.)

• Primary Centre: Southeast Asia (Malaysia and Philippines).
• Secondary Centres: Africa and Latin America.

6. Coffee (Coffea arabica)

• Primary Centre: Ethiopia.
• Secondary Centre of Diversity: Brazil and Central America.