centres of origin GPB202

Dr. NAVEENKUMAR K.L
Assistant Professor
Dept. Of Genetics and Plant Breeding

1. Dr. NAVEENKUMAR K.L
Assistant Professor
Dept. Of Genetics and Plant Breeding
UAHS Shivamogga
Centers of Origin of Crop Plants

2. Centres of Origin of Crop Plants
Cultivatedplantsarenotdistributeduniformlythroughout
theworld.
Someoftheofthecropspeciesshowgreatervariability
andtheirwildrelativesincertainareasoftheworld
In1926,N.I.VavilovproposedCentresofOrigin
Primarycentresoforigin:cropplantsevolvedfromwild
speciesintheareasshowinggreaterdiversityandcalled
themasPrimarycentresoforigin
Secondarycentresoforigin:insomeareasalthoughcertain
cropsshowdiversitybutdidnotoriginatethere

3. Why study of origin of crops is important?
1.Search for resistanceto diseases and pests.
2. Helps in directing efforts towards crop improvement
Eg: *In sugarcane S. Barberi and S. Sinensis are the result of
crosses between S. officinarum x S. Sportaneum As a result,
nobalizationof canes in sugarcane took place.
*In wheat A B D genomes have come from three different wild Sp.
namely T. monococcum, T. speltoids & T. squarrosato give rise to
cultivated hexaploid.
3. Useful in development of new crops
4. Useful in making collections

4. How to determine centresof origin ?
I. Based on presence ofwild Spp(Decondelle):in the areas of max.
diversity.
Problems 1. Difficult to establish true wild Spp.
2. Some crops lack wild Sp. Eq. Vicia faba
II. a) Archeological :
b) Historical :
c) Linguistic:
III. Evidences from Taxonomy
IV. Combination of I, II and III

5. 9. USA centre: Sunflower and H. tuberoses
Centres of Origin

6. Centers of Origin of Crop Plants
The eight Vavilovian Centres of Origin for crop plants.

8. Thelargestindependentcenterwhichincludes
themountainousregionsofcentralandwestern
China,andadjacentlowlands.
OLD WORLD
1. Apricot
2. Peach
3. Soybean
4. Adzuki bean
5. Velvet bean
6. Chinese yam
7. Radish
8. Chinese cabbage
9. Onion
10. Cucumber
Atotalof136endemicplantsarelisted,amongwhich
areafewknowntousasimportantcrops.

9. II.
This area has two sub-centers.
A. Main Center (Hindustan): Includes Assam and
Burma, but not Northwest India, Punjab, Northwest
Frontier Provinces.
1. Rice
2. Chickpea
3. Pigeon pea
4. Urd bean
5. Mung bean
6. Cowpea
7. Eggplant
8. Mango
9. Tamarind

10. Agro ecological zones of India -20
(for planning of agricultural development s well as sustainable
use of plant genetic resources for enhancement of crop
production and productivity)
Biogeographic classification of India -10 Zones
(Based on geography climate and pattern of vegetation).
Agro-climatic zones of India-15
(Based on the criteria of homogeneity in agrocharactestics –
Rain fall, temperature, soil, cropping and farming system)

11. Eight agro-ecological regions have been identified According to
chatterjee (1939) there are
1. Western HimalayasWheat, maize, ragi, rice, potato
2. Eastern HimalayasRice, wheat, jute, tea, maize
3. North Easter regionRice, maize, barley, citrus, banana,
Pineapple, cotton, sugarcane
4. Gangetic plainsRice, millets, Chickpea, Sorghum
5. Indus plainsDurum wheat, sesame, Tara Meera
6. Eastern peninsular (Eastern ghats) Rice, millets, grams,
Taros
7. Western peninsular Rice, sorghum, millets, grams, sugarcane,
turmeric,
8. Island region Coconut, chilli, Taros.
Phyto Geographical Zones of India

12. II B. Indo-Malayan Center: Includes Indo-China
and the Malaya .
Fifty-five plants were listed, including:
1. Yam
2. Banana
3. Coconut palm
4. Sugarcane
5. Clove
6. Black pepper
7. Pamelo

13. IncludesNorthwestIndia(Punjab,NorthwestFrontier
ProvincesandKashmir),
Afghanistan,Tadjikistan,Uzbekistan,andwesternTian-Shan.
Thiscenterlists43plantsincludingmanywheats.
1. Common wheat, T. vulgare
2. Club wheat, T. compactum
3. Shot wheat, T. sphaerocoecum
4. Pea
5. Lentil
6. Horse bean
7. Onion
8. Garlic
9. Grape
10. Apple
III. Central Asian Centre

14. IIncludes interior of Asia Minor (Anatolian peninsula in
Asian part of turkey), Iran and the highlands of
Turkmenistan.
This region lists 83 species including 9 species of wheat.
IV. Near-Eastern Center/Asian minor:

15. 1. Einkorn wheat, Triticum monococcum(2n= 14)
2. Durum wheat, Triticum durum(2n= 28)
3. Poulard wheat, Triticum turgidum(2n= 28)
4. Common wheat, Triticum vulgare(2n= 42)
5. Oriental wheat, Triticum orientale
6. Persian wheat, Triticum persicum(2n= 28)
7. Triticum timopheevi(2n= 28)
8. Triticum macha(2n= 42)
9. Triticum vavilovianum, branched (2n= 42)
IV. Near-Eastern Center/Asian minor:

16. Includes the borders of the Mediterranean Sea (Greece,
Italy, France).:
This region lists 84 plants including oliveand many
cultivated vegetables and forages.
V. Mediterranean Center:

17. 1. Durum wheat, Triticum durum expansum
2. Emmer, Triticum dicoccum(one of the centers)
3. Pea, Pisum sativum(large seeded varieties)
4. Lupine
5. Black mustard
6. Olive
7. Cabbage
8. Lettuce
9. Asparagus
10. Celery
V. Mediterranean Center:

18. Includes Abyssinia, Eritrea, Ethiopia and part of Somali.
This center lists 38 species; rich in wheat and barley.
VI. Abyssinian Center:

19. 1. Abyssinian hard wheat, Triticum durum abyssinicum
2. Grain sorghum, Andropogon sorghum
3. Pearl millet, Pennisetum spicatum
4. Cowpea, Vigna sinensis
5. Flax, Linum usitatissimum
6. Sesame, Sesamum indicum(basic center)
7. Castor bean, Ricinus communis(a center)
VI. Abyssinian Center:

20. VII. South Mexican and Central American Centre:
Includes southern sections of Mexico, Guatemala,
Honduras and Costa Rica.
NEW WORLD

21. 1. Maize, Zea mays
2. Common bean, Phaseolus vulgaris
3. Lima bean, Phaseolus lunatus
4. Sweetpotato
5. Pepper, Capsicum annuum, C. frutescens
6. Papaya, Carica papaya
7. Guava, Psidium guayava
8. Cashew, Anacardium occidentale
VII. South Mexican and Central American Centre:

22. VIII. South American Center:
1. Andean potato
2. Pepper
3. Tomato
4. Pumpkin
5. Egyptian cotton
6. Guava
7. Tobacco
Two sub-centers are found.
A. Peruvian, Ecuadorean, Bolivian Center: Comprised
mainly the high mountainous areas of Peru, Bolivia,
Ecuador.

23. VIII B. Brazilian-Paraguayan Center
1. Cassava
2. Groundnut
3. Rubber
4. Pineapple
5. Cashew

24. PRIMARYCENTRESOFDIVERSITYSITY.
1.Regionswithvastgeneticdiversity
2.Largenumberofdominantgenes
3.Mostlycropshaveevolvedfromwildspecies
4.Naturalselectionhasaconsiderableroletoplay.
SECONDARY CENTERSOFDIVERSITY
1.Areasoflessergeneticdiversity,butinsomecropsconsiderablevariationcanbe
found
2.Largenumberofrecessivegenes
3.Cropplantstendtohavemoredesirablefeatures
4.Bothnaturalandartificialselectionsoperate.
CENTRES OF DIVERSITY
CentresofDiversityareareaswherecultivatedplantspeciesandortheirwild
relativesshowsmuchgreatervariationthananywhereintherestofworld.

25. MICROCENTERS (Harlan1951):arethesmallareaswithin
thecentresofdiversityexhibitingtremendousgenetic
diversityofsomecropplants.
1.Smallareaswithinthepco/scoexhibitingtremendousgenetic
diversity.
2.Cropevolutiontendstoproceedatafasterrateinsuchareas
3.Importantforplantcollection&experimentalstudyof
evolutionofcultivatedspecies.
Nuclearcentres:Hawkes(1983)-4
Linkedthenuclearcentreswiththearchaeologicalevidenceto
providestrongproofsofagriculturalorigins

26. Zevan and Zhukovsky (1975)-proposed 12 mega gene centres.
1. Chinese –Japanese 7. Mediterranian
2. Indo-chinese Indonesian 8. European Siberian
3. Australian 9. African region
4. Hindustan 10. South American region
5. Central Asian 11. Central American
6. Near East-region 12. North American
MEGACENTERS :Centreswheretheplacewherecultivated
plantspeciesexhibitdiversityandmicrogenecentreisplace
wherewildspeciesoccur.
*Zhukovsky(StudentofNIVavilov)

27. SIR. N. I. VAVILOV
RussianbotanistNikolaiIvanovichVavilovorganizedand
tookpartinover100germplasmcollectionmissions.
HismajorexpeditionsincludedthosetoIran(1916),the
UnitedStates,CentralandSouthAmerica(1921,1930,
1932),theMediterraneanandEthiopia(1926-1927).
LAWOFHOMOLOGOUS SERIESOFVARIATION(1922)
-Characterfoundinonespeciesalsooccursinotherrelated
species
If you have a trait in one species it will probably be the same in
related species
Genetically closely related species and genera are characterized
by similar series of hereditary variation.
Ex:Diploid,Tetraploid,Hexaploidwheatsshowseriesifidentical
contrastingcharacters

28. Domestication

29. Domesticationistheprocessofbringing
wildspeciesunderhumanmanagement
Gopher plant (Hevea sp.)
Milkweed (Euphorbia lathyrus),
Kala jeera (Bunium persicum),
Domestication:

30. SelectionunderDomestication
Whendifferentgenotypespresentinapopulation
reproduceatdifferentrates,itiscalledselection.
Selectionisgroupedintotwotypes,onthe
basisoftheagencyresponsibleforit.
Apopulationmaybesimplydefinedasthegroupof
individuals,whichmateorcanmatefreelywitheachother.
1.Natural
2.Artificial

31. NaturalSelection:Theselectionthatoccursduetonatural
forceslikeclimate,soil,biologicalfactors(e.g.,diseases,
insectpests,etc.)andotherfactorsoftheenvironmentis
callednaturalselection.
In1962,Nichlsonproposedthatnaturalselectionmaybe
seentooperatethroughtwomechanisms,
viz.;(l)environmentalselectionand(2)competition.
Environmentalselectionactsagainstallsuchgenotypes
thatareunabletocopewiththeenvironmentalstresses.

32. Naturalselectionthroughcompetitionoccursincrop
populationswhereaplanttakesupmorewater,nutrientsorlight
thananotherattheexpenseoftheother.
ArtificialSelection:iscarriedoutbymanandisconfinedto
domesticatedspecies.Itallowsonlytheselectedplantsto
reproduce,ordinarily.makesplantsmoreusefultomanand
generallyleadstoamarkeddeclineingeneticvariabilityinthe
selectedprogenies/populations.
TypesofSelection
(1)Directionalselection,
(2)Stabilizingselection
(3)Disruptiveselection.

33. DirectionalSelection:Whenindividualshavingtheextreme
phenotypeforatraitoragroupoftraitsareselectedfor,itis
calleddirectionalselection.
Eg.Heavymetaltolerance
StabilizingSelection:When selectionfavoursthe
intermediatephenotypeandactsagainsttheextreme
phenotypes,itistermedasstabilizingselection
DisruptiveSelection:Ineach'ecologicalniche'adifferent
'phenotypicoptima'isselectedforsothatthepopulation
ultimatelyconsistsoftwoormorerecognizableforms;sucha
selectioniscalleddisruptiveselection..

34. Plant Introduction

35. Plant Introduction
Taking a genotype or group of genotypes of a plant into a
new area or region where they are not grown previously.
It may be introduction of new variety, wild relatives of crop
species or new plant species
It may be between countries or within a country
Ex: bIntroduction of Potato and tomato into India
y: Introduction of Wheat in West Bengal and Rice in
Punjab

36. Types of Plant Introduction
•Primary Introduction:
–Introduced genotype is directly released for commercial
cultivation without any alteration.
–Ex: Semi-dwarf wheat varieties, Sonora 64, Lerma Rojo,
•Secondary Introduction:
–The introduced variety is improved by selection or hybridization
with local genotypes to transfer one or few characters from
introduced variety into local variety.
–Ex: Wheat varieties, Kalyansonaand Sonalika

37. Purpose of Plant Introduction
1.Entirely new crop:To bring under cultivation
New crop species which is not under cultivation
Ex: Maize, Potato, Tomato in India
2.New Varieties:
3.Utilization in crop improvement
programme
4.Utilization in scientific studies: To study
origin, evolution, biosystematics of crop plants.
5.Used for Aesthetic value: Ornamental crops
6.To protect from pest and disease:
Introduction of coffee from south Africa to South
America to protect from leaf rust.

38. Merits of Plant Introduction
1.It provides entirely new crop
2.New variety either by primary or secondary
introduction
3.To protect variability from genetic erosion
4.Quick and economical method of crop
improvement
5.Crop species may be free from disease and pest in
new areas

39. Demerits of Plant Introduction
•Introduction of
–New weeds: Argemone mexicana, Phylaris minor
etc into India
–Diseases: Late blight of potato from Europe,
Coffee rust, bunchy top of Banana
–Insect pest: Potato tuber moth, Woolly aphid of
apple
•Ornamentals-turned-weeds
–Water hyacinth and Lantana camara

40. Acclimatization
•Factors affecting acclimatization:
–Mode of pollination
•Cross pollinated crops adapt faster than self pollinated
crops
–Extent of genetic variability
•Higher the variability faster the adaptability
–Duration of life cycle
•Annual crops acclimatize faster than perennials
•It is the ability of a crop or crop variety to
become adapted to new climatic conditions