Plant introduction and domestication

1. origin
&
Plant
Introduc
tion
Dr. Kirpa Ram
(Assistant Professor, Botany)
Ph. +91-9468393474,
Mail-
dr.kirparamjangra@gmail.com

2. Concepts of center of origin
• Many people believed that centers of origin are also centers of diversity. But,
the centers of diversity may not represent the centers of origin of crop plants.
• Although a few species may have been originated separately at more than
one place, but most species had their origin at a certain place and then
spread elsewhere.
• In other words, in the center of origin a crop is generally confined to one
place, whereas the center of diversity may be found at more than one place.
What is Center of Origin?
The center of origin is a geographical area where the particular group of
organisms (either domesticated or wild) first originated on earth.

3. 1. China; 2. India; 2a. the Indo-Malayan region; 3. Central Asia (including Pakistan, Punjab,
Kashmir, Afghanistan and Turkestan); 4. the Near East (Fertile Crescent); 5. the
Mediterranean; 6. Ethiopia; 7. Southern Mexico and Central America; 8. South America
(small regions of Ecuador, Peru, Bolivia, Chile, and Brazil-Paraguay).

4. Nikolai Ivanovich Vavilov
A prominent Russian and Soviet agronomist, botanist
and geneticist best known for having identified the
centres of origin of cultivated plants. He devoted his life
to the study and improvement of wheat, corn, and other
cereal crops that sustain the global population. The
concept of centres of origin was developed by him in
1926. Vavilov elaborated on the work of Engelbrecht
(1916) and considered the regions showing the greatest
diversity with presence of wild relatives as the centres of
origin of the crop plant.
Vavilov and his colleagues visited several countries and
collected a large number of crop plants and their wild
relatives. They used this collection in Russian breeding
programme of developing improved varieties. His
deductions were based on evidences from morphology,
anatomy, cytology, genetics, plant geography and
distribution.

5. What is the Vavilov’s work?
Vavilov was a follower of De Candolle. He travelled over hundred locations around the world for
germplasm collection and study crop variability.
• In 1920 he proposed the law of homologous series of variation, which states that the related
species share certain common characters.
• Vavilov noted that the centers of origin of cultivated plants occurred mostly in mountainous
regions between the Tropic of Capricorn (23°28′) south of the equator and about 45°N of the
equator in the Old World.
• In the New World crop domestication occurred between the two tropics (Cancer and Capricorn)
approximately.
• Vavilov considered that “as a rule the primary foci of crop origins were in mountainous
regions, characterized by the presence of dominant alleles.”
• In his work entitled The Phytogeographical Basis for Plant Breeding (Vavilov 1935) he
summarizes and pulls together all his previous work on centers of origin and diversity. In this he
recognizes eight primary centers, as follows. These centers are still recognized in spite of several
arguments against them.

6. Types of Centers of Origin
• Primary Center: Where the crop has been
actually domesticated- expected to be
centers of diversity (8 primary centers).
• Regions of vast genetic diversity of crop
plants.
• These are original homes of the crop plants
which are generally uncultivated areas like,
mountains, hills, river valleys, forests, etc.
• Wide genetic diversity
• Large number of dominant genes
• Wild characters
• Exhibit less crossing over
• Natural selection operates
• Secondary Center: Where it has been
introduced from primary center and
adapted to show high variation – often
showing higher diversity of a particular
crop than in its primary center ( 3
secondary centers)
• Vavilov suggested that valuable forms of
crop plants are found far away from their
primary area of origin which he called
secondary centers of origin or diversity.
• These are generally the cultivated areas.
• Lesser genetic diversity
• Large number of recessive genes
• Mostly desirable characters
• Exhibit more crossing over
• Both natural and artificial selections
operate

7. I. The Chinese Center - in which he recognizes 138 distinct species of
which probably the earlier and most important were cereals, buckwheats
and legumes.
II. The Indian Center (including the entire subcontinent) - based
originally on rice, millets and legumes, with a total of 117 species.
III. The Inner Asiatic Center (Tadjikistan, Uzbekistan, etc.) - with wheats,
rye and many herbaceous legumes, as well as seed-sown root crops and
fruits, some 42 species.
IV. Asia Minor (including Transcaucasia, Iran and Turkmenistan) - with
more wheats, rye, oats, seed and forage legumes, fruits, etc., some 83
species.
Primary Centers of Origin

8. V. The Mediterranean Center - of more limited importance than the others
to the east, but including wheats, barleys, forage plants, vegetables and
fruits -especially also spices and ethereal oil plants, some 84 species.
VI. The Abyssinian (now Ethiopian) Center - of lesser importance, mostly a
refuge of crops from other regions, especially wheats and barleys, local
grains, spices, etc., some 38 species.
VII.The South Mexican and Central American Center - important for
maize, Phaseolus and Cucurbitaceous species, with spices, fruits and fibre
plants, some 49 species.
VIII.South America Andes region (Bolivia, Peru, Ecuador) - important for
potatoes, other root crops, grain crops of the Andes, vegetables, spices and
fruits, as well as drugs (cocaine, quinine, tobacco, etc.), some 45 species.

9. • IIa. The Indo-Malayan Center (including Indonesia, Philippines, etc.) -
with root crops (Dioscorea spp., Tacca, etc.) preponderant, also with fruit
crops, sugarcane, spices, etc., some 55 species.
• VIIIa. The Chilean Center - only four species - outside the main area of
crop domestication, and one of these (Solarium tuberosum) derived from
the Andean center in any case. This could hardly be compared with the
eight main centers.
• VIIIb. Brazilian-Paraguayan Center - again outside the main centers
with only 13 species, though Manihot (cassava) and Arachis (peanut) are of
considerable importance; others such as pineapple, Hevea rubber,
Theobroma cacao were probably domesticated much later.
Secondary Centers of Origin

10. Plant Introduction
Plant introduction is a process of introducing plants (a genotype or a group of
genotypes) from their own environment to a new environment.
• The process of introduction may involve new varieties of crop or the wild
relatives of crop species or totally a new crop species for the area.
Objectives of Plant Introduction
1. To introduce high yielding varieties to increase food production. E.g.
Rice and wheat.
2. To enrich the germplasm collection. E.g. Sorghum, Groundnut.
3. To get new sources of resistance against both biotic and abiotic
stresses.
4. To introduce new plant species there by creating ways to build up new
industries.E.g. Oil palm

11. History of plant introduction
During the sixteenth century and later, the Portuguese, British, French and
Dutch, in the process of colonisation, introduced many plants in different
regions.
• In India, Portuguese introduced new-world crops, such as maize,
groundnut, chilli, potato, sweet potato, guava, custard apple, pineapple,
cashewnut and tobacco
• British East India Company introduced - tea, litchi and loquat from China,
and cabbage, cauliflower and other winter vegetables
• Classical examples ,
1. Introduction of sunflower to USSR from Central Mexico/USA
2. Chinese soybean to North America
3. Ethiopian coffee to Central and South America

12. Types of Plant Introduction
• Based on adaptation
1. Primary Introduction - Variety is well adapted to the new environment,
released for commercial cultivation without any alteration in the original
genotype. Sonora 64, Lerma Roja in wheat and TN-1, IR-8 and IR-36 in
rice.
2. Secondary Introduction - Introduced variety may be subjected to
selection & hybridization to isolate a superior variety. Kalyan Sona and
Sonalika wheat varieties selected from material introduced from
CIMMYT, Mexico.
• Based on utilization
1. Direct Introduction - New variety takes no time for establishment.
2. Indirect Introduction - New variety takes some time for establishment.

13. Procedure of Plant Introduction
(a) Ways of Procurement of Plants or
Germplasm:
• Requisition for introduction of new crop
plant or new varieties should be
submitted to NBPGR (National Bureau
of Plant Genetic Resources) within the
country or to IBPGR (International
Bureau of Plant Genetic Resources).
• The material may be obtained on an
exchange basis from friendly countries
• or the material can also be purchased or
obtained as free gift from individuals or
organizations.
(b) Packaging and Despatch:
• part of the plant for propagation
of that species is known as
propagule
• propagule may be seeds, tubers,
runners, suckers, stolons, bulbs,
root cuttings, buds
• Propagule are packed carefully
and despatched

14. c) Entry and Plant Quarantine:
• On receipt of the material the entry inspection is done by the country for
other contaminants and the presence of insect, diseases, nematodes are
checked.
• The materials are treated with insecticides, fungicides or nematicides and
then released to the user.
(d) Cataloguing:
• Introduced specimen is given a number regarding species, variety, place of
origin and the data are recorded.
(e) Evaluation:
• performance at different substations are evaluated
• evaluated under different environments.
(f) Multiplication and Distribution:
• Promising introduced materials are propagated and then released as
varieties after necessary trials.

15. Plant Introduction Agencies in India
In India centralized plant introduction agency was initiated at IARI in 1946 at
New Delhi.
• In 1956 it was expanded as the "Plant Introduction and Exploration
Organization" and in 1961, it was made an independent division in IARI as
the "Division of Plant Introduction".
• In 1976 division was reorganized as NBPGR. This bureau is responsible for
the introduction and maintenance of germplasm of agricultural and
horticultural crops.
In addition to bureau there are some other agencies,
i. FRI (Forest Research Institute),
ii. Botanical Survey of India,
iii. The Central Research Institute e.g. Tea, Coffee. Sugarcane, Potato,
Tobacco etc.

16. Import rules and regulations
The import and export of seeds, plants, plant products and planting material in India
are regulated by the rules and regulations framed under the Destructive Insects and
Pests Act (DIP Act) of 1914
The main features of the Act are:
1. The Central Government may prohibit or regulate importation into India of any
article or class of articles likely to be injurious to any crop.
2. The Central Government may prohibit or regulate the export from a State or the
interstate transport of any article or class of articles likely to be injurious to any
crop.
3. The Central Government may make rules prescribing the nature of documents to
accompany any article or class of articles.
4. The State Government may make rules concerning the detention, inspection,
disinfestation or destruction of any article or class of articles likely to be injurious
to any released variety.
5. Seed were not originally included in the DIP Act, the Government of India passed
the Plants,Fruits and Seeds (Regulation of Imports into India) Order of 1984, had
17 crops are included and conditions for their import are stipulated.

17. Merits/ Demerits of Plant Introduction
Merits of Plant Introduction
1. Entirely new crop plant is derived.
It provide new crop varieties.
2. Quick & economical method of crop
improvement.
3. Protection of crops from damage by
introducing them in to disease free
areas.
4. Development of superior varieties
through selection & hybridization by
using introductions.
Demerits of Plant Introduction
1. Introduction of weeds along with
introduced materials.
2. Introduction of diseases along with
introduced materials.
3. Introduction of insect pest along with
introduced materials.
4. Some plants introduced as
ornamental species became noxious
weeds.
5. Some introduced plants are threat to
the ecological balance.