PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY

College of Agriculture, Rajendranagar, Hyderabad- 500030

Presented by, Ajay Kumar Chandra

RAM/14-97

M.Sc. (Ag) Mol. Biology & Biotechnology

CENTRES OF ORIGIN- BIODIVERSITY AND ITS

SIGNIFICANCE

Introduction

• Center of origin is the region of the world where a crop is believed to have originated.

• Knowledge of time and place of origin is important - For taxonomists and plant breeders. - Present day plants are much different than the wild varieties.

Genetically and morphologically different Several genes (characteristics) are selected

- Loss of plants is loss of gene pools from which new traits can be retrieved. - Breeders used it to identify diverse forms of the species with useful traits

or characters for crop improvement. - Used by crop protectionist in designing biological control e.g. cassava

meal bug .

Where did our crops originate?

• Evidence for the origins of agriculture comes from archaeological excavations and botanical observations on the distribution of the relatives of our domesticated crops.

Alphonse De Candolle(1883)• Wrote a book “PHYTOGRAPHIE” on the origin of cultivated plants.

• Wild relatives of the major crops (rice, wheat, beans).

• French systematic botanist (taxonomist) proposed that the crops of the world originated in 3 centers:

1). Mesoamerica 2). the Fertile Crescent of the Middle East 3). South East Asia.

• Criteria for recognizing centers of origin– Places where a plant grows spontaneously in a wild state.– Places where fragments of plants in old deposits and buildings (archeological

and palaeobotanical) are found.– Archives describing the adventures of travelers.– Philogical (naming) origin.

N. I. Vavilov (1926)

• Vavilov concluded that the most likely areas of origin were, where the plant was cultivated and the wild ancestors grew.Further, the areas of origin should be areas in which there was lots of variation.

• He was interested in the presence of wild ancestors.

In 1926 he published "Studies on the Origin of Cultivated Plants" which described his theories on the origins of crops.

• Based on genetics, chromosome studies, and anatomical data.

(1) Mexico-Guatemala, (2) Peru-Ecuador-Bolivia, (2A) Southern Chile, (2B) Southern Brazil, (3) Mediterranean, (4) Middle East, (5) Ethiopia, (6) Central Asia, (7) Indo-Burma, (7A) Siam-Malaya-Java, (8) China and Korea.

Cont….• Vavilov concluded that each crop has a characteristic primary center of

diversity which is also its center of origin.

• Eight areas were recognized and suggested as centers from which all of our major crops were domesticated. Later, he modified his theory to include "secondary centers of diversity" for some crops.

• 1n 1926, N.I. Vavilov, proposed and classified as 1). Primary centers of origin - Crops evolved from wild species in the areas showing maximum

diversity. 2). Secondary centers of origin - in some areas, certain crop species show considerable

diversity of forms, although they did not originate there.

• largest & oldest independent center . - Includes the mountainous regions of central and western China, and

adjacent lowlands. - A total of 136 endemic plants are listed. a). Primary center of origin- soybean, radish, orange, pear, millets,

oats and Chinese cabbage. b). secondary center of origin- maize, rajma, cowpea, turnip and

sesame.

Chinese Center of origin

Mediterranean Center• Includes the borders of the Mediterranean Sea. • 84 plants are listed for Cereals and Legumes: durum wheat, Mediterranean oats, sand oats,  pea. Forage Plants: Egyptian clover, white clover Fiber Plants: flax, rape, black mustard, olive Vegetables: garden beet, cabbage, turnip, lettuce, asparagus. Ethereal Oil and Spice Plants: peppermint.

Indian (Hindustan) Center• Two sub-centers 1). Indo-Burma: Main Center (India): Includes Assam and Burma, but not

Northwest India, Punjab, nor Northwest Frontier Provinces. - includes 117 plants, such as Cereals and Legumes: rice, chickpea, pigeonpea, mung bean,  cowpea. Vegetables and Tubers: eggplant, cucumber, radish, taro, yam Fruits: mango, orange, tangerine, citron, tamarind Sugar, Oil, and Fiber Plants: sugar cane, coconut palm, sesame,  safflower,

 cotton, jute. Spices, Stimulants, Dyes, and Miscellaneous: hemp, black pepper, 

 sandalwood, bamboo. 2). Siam-Malaya-Java: Includes Indo-China and the Malay Archipelago,

- includes 55 plants, such as Fruits: banana Miscellaneous: : coconut palm, sugarcane, clove

Central Asiatic Center• Includes Northwest India (Punjab, Northwest Frontier Provinces and Kashmir),

Afghanistan, Tadjikistan, Uzbekistan, and western Tian-Shan.• includes 43 plants species, such as Grains and Legumes: wheat,  peas, lentil, chickpea,  mustard,   sesame, mung

bean. Fiber Plants: hemp, cotton Vegetables: onion, garlic, spinach, carrot Fruits: pear, almond, grape, apple.

Middle East or Persian• Includes interior of Asia Minor, all of Transcaucasia, Iran, and the highlands of Turkmenistan. 83 plants species Grains and Legumes: common wheat, oriental wheat, Persian wheat, lentil

rye, Mediterranean oats, common oats. Forage Plants: alfalfa, Persian clover Fruits: fig, pomegranate, apple, pear,  cherry.

Ethiopia• Includes Abyssinia, Eritrea, and part of Somaliland. • 38 species listed; rich in wheat and barley. Grains and Legumes: Abyssinian hard wheat, barley, sorghum, pearl

millet, African millet, cowpea. Miscellaneous: sesame, castor bean, coffee, okra.

Central American or South Mexican Center

• Includes southern sections of Mexico, Guatemala, Honduras and Costa Rica. Grains and Legumes: maize, common bean,  jack bean, grain amaranth Melon Plants: malabar gourd, winter pumpkin. Fiber Plants: upland cotton, bourbon cotton, henequen (sisal) Miscellaneous: sweetpotato,  pepper, papaya, guava, cashew, wild black

cherry,  cherry tomato, cacao.

South American Center• 62 plants listed.• Three sub centers i) Peru, Ecuador, Bolivia Center: - Comprised mainly of the high mountainous areas Root Tubers: Andean cultivated potato species. Grains and Legumes: starchy maize, lima bean, common bean Vegetable Crops:  tomato, ground cherry, pumpkin, pepper Fiber Plants: Egyptian cotton Fruit and Miscellaneous: cocoa,  guava, quinine tree, tobacco ii) Chile Center (Island near the coast of southern Chile) Common potato , Chilean strawberry iii) Brazil-Paraguay Center peanut, rubber tree, pineapple, Brazil nut, cashew.

USA centre• No major cultivated crop origins

- relies on introduced crops - many minor fruit and nut crops: American grapes and plums,

pecan, chestnut, hickory nut, hazelnut, black walnut, persimmon, blueberry, raspberry, blackberry, and cranberry.

- Additional crops: sunflower ,Jerusalem artichoke- some grasses- many ornamentals- Timber tree species

• Opposed Vavilov’s eight centers.

• Harlan concluded that there were three "centers": 1). Near East 2). Northern China 3). Meso-America

• Three other areas with diffuse origins (S.E. Asia, S. America, and much of Africa) that he called "non-centers". Further, it had become clear that a "center of origin" often was not the same as a "center of diversity". • Harlan concluded that it is very difficult to separate the origin and later expansion of a successful crop.

Jack R. Harlan

Biodiversity and Agriculture are strongly interdependent

• Biodiversity is the basis of agriculture. It has enabled farming systems to evolve ever since agriculture was first developed some 10,000 years ago.

• Biodiversity is the origin of all species of crops and domesticated livestock and the variety within them.

• It is also the foundation of ecosystem services essential to sustain agriculture and human well-being. Today's crop biodiversity are the result of many thousands years of human intervention.

• Biodiversity and agriculture are strongly interrelated because while biodiversity is critical for agriculture, agriculture can also contribute to conservation and sustainable use of biodiversity.

Indeed, sustainable agriculture both promotes and is enhanced by biodiversity.

• Maintenance of this biodiversity is essential for the sustainable production of food and other agricultural products and the benefits these provide to humanity, including food security, nutrition and livelihoods.

Biodiversity

• Biodiversity refers to the total variability present within and among species of all living organisms and their habitats.

Or Biodiversity is the totality of genes, species and ecosystem in a region.

• Three types 1). Genetic diversity - Variation within genetic constitution of an organism. 2). Species diversity - variation of species within a region. 3). Ecosystem diversity - variation in ecosystems within a country.

• Crop genetic diversity provides an insurance against crop losses due to disease and pest. E.g. land races provides protection from biotic and abiotic stresses due to genetic

diversity.

• Biodiversity is getting eroded due to factors responsible for genetic erosion.

Center of Diversity• Center of diversity is the region of the world where the greatest variability in crop species is

believed to have occurred.

•  Centers of origin are also considered centers of diversity.

• A Vavilov Center (or, Vavilov Center of Diversity) is a region of the world first indicated by Dr. Nikolai Ivanovich Vavilov to be an original center for the domestication of plants.

• Types of centers of diversity 1). Primary center of diversity 2). Secondary center of diversity, and 3). Micro-centres

Center of DiversityFeature Primary centres of diversity Secondary centres of diversity

Definition Regions of vast genetic diversity of crop plants

Valuable forms of crop plants are found far away from their primary areas of origin.

Genetic diversity Wide Lesser than primary

Regions includes Original homes of the crop plants which are generally uncultivated areas like mountain, hills, river valleys.

Generally cultivated areas

Genetic activity Dominant genes Recessive genes

Characters contains Wild Characters Desirable Characters

Crossing over Exhibits lesser Exhibits more

Selection operates Only natural Both natural and artificial

Microcenters

• J. R. Harlon made exploration to turkey and added micro centres.

• Small areas within the centres of diversity exhibit tremendous genetic diversity of some crop plants, referred as micro centres.

• These are important sources for the collecting valuable plant forms and also for the study of evolution of cultivated species.

• The main features are: a). They represents small areas within the centres of diversity. b). Exhibit tremendous genetic diversity. c). The rate of natural evolution is faster than larger areas. d). They are important sites for the study of crop evolution.

Mega- gene centres• Zeven- zhukovsksy (1975) and zeven-de Wet (1982), recognised 12- mega gene

centres of crop plant diversity and a number of micro gene centres of wild growing species related to our crop plants.

• These includes: 1). Chinese- Japanese region 2). Indo- Chinese- Indonesian region 3). Australia - New Zealand region 4). Indian (Hindustan) region 5). Central Asian region 6). Near eastern Asian region 7). Mediterranean region 8). African 9). Europe - Siberia 10). South American 11). Mexico & Central America 12). North America

Genetic erosion in Agricultural biodiversity

• Genetic erosion in agricultural biodiversity is the loss of genetic diversity, including the loss of individual genes, and the loss of particular combinations of genes (or gene complexes) such as those manifested in locally adapted landraces or breeds.

• The major driving forces behind genetic erosion in crops are: - Variety replacement - Land clearing - Overexploitation of species - Population pressure - Environmental degradation -  Overgrazing - Govt. policy and - Changing agricultural systems.

Why Agricultural biodiversity matters?

• Foundation of agriculture.• Can provide a cost-effective way for farmers to manage pests and diseases.• Gives farmers options to manage climate risks.• Can contribute to health and nutrition.• Can play a role in sustaining soil health, food and habitat for important

pollinators and natural pest predators that are vital to agricultural production.• Traditional knowledge and culture is often based on local species diversity and

its use.

Important:

What's the Problem?

• Agriculture has to face two main challenges in relation with biodiversity: 1). To sustain agricultural biodiversity and ecosystem services provided by, and

necessary for agriculture, and 2). To mitigate the negative impacts of agricultural systems and practices on biodiversity

which is not used directly whether in the same or other ecosystems?

• The major challenge for agriculture is to ensure food security, adequate nutrition and stable livelihoods for all, now and in the future, by increasing food production while adopting sustainable and efficient agriculture, sustainable consumption of resources, and landscape-level planning to ensure the preservation of biodiversity.

Organizations, technology and solutions

The implications of crop diversity are at both the local and world level, and numerous organizations are emerging with great global backing in response to this ideology.

• Plant Genetic Resources Institute (IPGRI – now known as Biodiversity International), the International Institute of Tropical Agriculture (ITTA), the Borlaug Global Rust Initiative, and the International Network for Improvement of Banana and Plantain (INIBAP), Members of the United Nations, at the World Summit on Sustainable Development 2002 at Johannesburg.

• The Global Crop Diversity Trust ,ensure the conservation and availability of crop diversity for food security worldwide.

• The Consultative Group on International Agricultural Research (CGIAR) is a consortium of International Agriculture Research Centers (IARC) conduct research on and preserve germplasm..

• National germplasm storage centers including the U.S. Department of Agriculture's National Center for Genetic Resources Preservation, India's National Bureau of Plant Genetic Resources (NBPGR), and the Australian Network of Plant Genetic Resource Centers.

• Organizations such as the World Resources Institute (WRI) and the World Conservation Union (IUCN) are non-profit organizations that provide funding and other support to off site and on site conservation efforts.

Thanks have a nice day…