Plant genetic resources their utilization and conservation in crop improvement

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
PLANT GENETIC RESOURCES

2. PLANT GENETIC RESOURCES

3. Whatareplantgeneticresources?
Plantgeneticresources(PGR)arethemostvaluable
andessentialbasicrawmaterialstomeetthe
currentandfutureneedsofcropimprovement
programmes.
Aimedatdevelopingnewvarietiesforincreasedcrop
productions.
Comprisesnativelandraces,localselections,elite
cultivarsandwildrelativesofcropplants.

4. PLANT GENETIC RESOURCES?
Plant genetic resources
24,000 plant species –described
3000 –human use
30 plant species –95% basic needs
Thesumtotalofallhereditarymaterial/
allelicsourcesofvariousgenespresentina
cropspeciesanditswildrelatives.
OR
Itisthegeneticwealthofacropovera
periodofevolution.Itistherawmaterial
forfurthercropimprovement

5. PLANT GENETIC RESOURCES
Representstheentiregeneticvariabilityor
diversityavailableinacropspecies.
Consistsof
1.Landraces
2.Moderncultivars,
3.Obsoletecultivars,
4.Advancebreedinglines/Breedingstocks,
5.Wildformsofcultivatedspecies
6.Wildrelatives
7.Mutants
Includesbothcultivatedandwildspeciesand
relativesofcropplants.

6. Landraces
Primitivecultivarsselectedandcultivated
bythefarmersfrommanygenerations.ex:
Featuresoflandraces:
Landraceswerenotdeliberatelybred
likemoderncultivars.
Landraceshavehighlevelofgenetic
diversitywithresistancetobioticand
abioticstresses.
Landraceshavebroadgeneticbasefor
wideradaptability.
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

7. Theydifferinadaptationtotype,timeofseeding,date
ofmaturity,height,nutritivevalueandotherproperties.
Littleresponsetoselectionforhighyield
Theyarelessuniformandlowyielders.

8. Obsolete cultivars
•Improved varieties of recent past are known
as obsolete cultivars.
•They are the varieties which were popular
earlier and now have been replaced by new
varieties.
•These varieties have several desirable
characters & constitute an important part of
genepool.
•Ex: wheat varieties of K68, K65, Pb591
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

9. Modern cultivars
Currently cultivated high yielding varieties
Also known as improved cultivars or advance
cultivars.
Used as parents in the breeding programmes
High yield potential and uniformity as compared
to obsolete varieties and land races.
Modern cultivars have narrow genetic base and
low adaptability compared to land races.
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

10. Advanced breeding lines
•advanced cultures which are not yet
ready for release to farmers
•Sometimes they are not very much
productive, but valuable for various
economic characters.
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

11. Wild forms of cultivated species
Highdegreeofresistancetobioticand
abioticstresses
Theycaneasilycrosswithcultivated
species.
Wildformsofmanycropspeciesare
extinct.
Theyconstitutesmallpartofgenepool.
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

12. •Those naturally occurring plant species which
have common ancestry with crops
•can cross with crop species
•important sources of resistance to biotic
abiotic stresses
•It is used as last resort in crop improvement
programmes,
–(1) hybrid sterility
–(2) hybrid viability and
–(3) transfer of several undesirable genes to the
cultivated species along with desirable alleles.
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relativesand
•(7) Mutants.
Wild relatives

13. Mutants
Whenthedesiredcharacternotfoundin
cultivatedandtheirwildrelatives
Naturalandinducedmutations
Extravariabilitycreatedthroughinduced
mutations
Maynotbereleasedasavariety,butthey
areaddedinthegenepool.
Ex:rice-jaganth,wheat-Norin10
Components of Genetic
Resources
•(1) Land races,
•(2) Obsolete
cultivars,
•(3) Modern cultivars,
•(4) Advanced
breeding materials,
•(5) Wild forms of
cultivated species,
•(6) Wild relatives and
•(7) Mutants.

14. GENEPOOL
Theconceptofgenepoolswasproposedby
HarlanandDeWet(1971)
Genepoolconsistofallthegenesandtheiralleles
presentinallsuchindividualswhichhybridizeor
canhybridizewitheachother.
Thegenepoolclassifiedinto4groups
1.Primarygenepool:(GP1)
easytocross,fertilehybrids,usefulforbreeding
2.Secondarygenepool:(GP2)
partialfertilehybridswithprimarygenepool
3.Tertiarygenepool:(GP3)
sterilehybridswithprimarypool
4.QUATRANAYgenepool:(GP4):GMOs

15. RICE
QUATRANAY gene pool:
GOLDEN RICE

16. SUNFLOWER

17. Thesumtotalofallhereditarymaterial/allelicsourcesofvariousgenes
presentinacropspeciesanditswildrelatives.
Thegermplasmisacollectionoflargenumberofgenotypesofacrop
speciesanditswildrelatives.
Features:
It represents the entire genetic variability
It includes land races, modern cultivars, obsolete cultivars, breeding
lines , special genetic stocks, wild forms and wild relatives
Collected from centers of diversity, gene bank, gene sanctuaries,
farmers field, market and seed companies
GERMPLASM

19. Field
Genebank
SeedGenebank
In Situ
(in original habitat,
dynamic conservation)
Ex Situ
(outside habitat,
Static conservation)
National
Parks
Biosphere
reserves
Gene
Sanctuaries
On-farm
Wildspecies
Wildrelatives
Landraces
Traditional
varieties
Crop
genebank
Arboretum Herbal
garden
Botanical
garden
InVitro
Genebank
Cryobank
DNAbank
Strategies forConservation

20. Conservation Strategies
Ex situ
In situ
•Seed gene bank
•In vitro storage
•DNA storage
•Pollen storage
•Field gene bank
•Botanical garden
•Natural park
•biosphere reserve
•Gene sanctuary
•On-farm
•Home gardens

21. Germplasm Conservation Strategies
–Ex situconservation
Conservation of Germplasm away from its natural
habitat.
–In situconservation
The conservation of germplasm in its natural habitat or in
the area where it grows naturally.

22. 1.Seed gene bank : Germplasm is stored as Seeds.
1.Easy, relatively safe and requires minimum space
Based on storability classified into two types
a) Orthodox seeds:
-Dried to low moisture content 5%
-Stored at low temperature
-No loss in viability
Ex: Corn, Wheat, Rice, Carrot, Cotton, Sunflower
b) Recalcitrant seeds
-Decrease in moisture below 12-30% -drastic loss in variability
-It is very difficult to store this kind of seeds
Ex: Citrus, Cocoa, Coffee, rubber, oil palm, mango, jackfruit, etc.
Ex SituGermplasm Conservation

23. Ex situtechniques
Seed storage conservation
•Collection of seed samples at one location and their transfer to a gene
bank for storage.
•The samples are usually dried to a suitable low moisture content and
then kept a sub-zero temperatures.
Long-term storage at the IRRI gene
bank

25. Ex situtechniques
Seed storage conservation
Advantages:
1.Efficient and reproducible
2.Feasible for medium and long-term secure storage
3.Wide diversity of each target taxon conserved
4.Easy access for characterization, evaluation and utilization.
5.Little maintenance once the material is conserved.
Disadvantages:
1.Problems storing seeds of recalcitrant species
2.Freezes evolutionary development
3.Genetic diversity may be lost with each regeneration cycle

26. Ex situtechniques
Field gene bank
•Collection of seed or living material from one location and its
transfer and planting at second site.
•Large numbers of accessions of a few species are usually conserved.
Characterization and evaluation of Taro, Papaya and Otaheite in Java (IPGRI).

27. Ex situtechniques
Field gene bank
Advantages:
1.Suitable for conserving recalcitrant species
2.Easy access for characterization, evaluation and utilization
Disadvantages:
1.Material is susceptible to pests, diseases and vandalism
2.Involves large areas of land, but even then genetic diversity
3.is likely to be restricted
4.High maintenance cost

28. Ex situtechniques
In vitrostorage
•Collection and maintenance of explants (tissue samples) in a
sterile, pathogen-free environment.
CIP, in vitrogene bank
(www.cipotato.org)
In vitroculture of banana
germplasm

29. Ex situtechniques
In vitrostorage
Advantages:
1.Relatively easy long-term conservation for large number of
recalcitrant, sterile or clonal species
2.Easy access to evaluation and utilization
Disadvantages:
1.Risk of somaclonal variation
2.Need to develop individual maintenance protocols for most
species
3.Relatively high level technology and maintenance costs

30. Ex situtechniques
DNA/ Pollen storage
Collection of DNA or pollen and storage in appropriate
condition, usually refrigerated conditions.
Advantages:
Relatively easy, low cost of conservation
Disadvantages:
DNA-RegenerationofentireplantsfromDNAcannotbeenvisagedat
present
-Problemwithsubsequentgeneisolation,cloningandtransfer
Pollen-Needtodevelopindividualregenerationprotocolstoproduce
haploidsplants;furtherresearchneededtoproducediploid
plants.
-Onlypaternalmaterialconservedbutmixturesfrommany
individualscouldbeenvisaged.

31. In situtechniques
•These techniques involve maintenance of
genetic variation at location where it is normally
grown, either in wild or traditional farming
systems.

32. In situtechniques
Natural park and biosphere reserve
•Location, management, and monitoring of genetic diversity in
natural wild populations within defined areas designated for
active, long-term conservation.
Naturalprotected area management zone in Turkey where crop wild relatives are
found
(www.ipgri.cgiar.org; International Plant Genetic Resources Institute)

33. In situtechniques
Natural park and biosphere reserve
Advantages:
1.Dynamic conservation in relation with environmental changes, pest and
diseases
2.Appropriate method to recalcitrant species
3.Possibility of multiple target taxa reserves and conservation of a diverse
range of wild relatives
Disadvantages:
1.Materials not easily available for utilization
2.Vulnerable to natural and man-directed disasters
3.Appropriate management regimes poorly understood
4.Requires high level of active supervision and monitoring

34. In situtechniques
On-farm
•Sustainable management of genetic diversity of locally developed
traditional crop varieties with associated wild and weedy species
or forms by farmers within traditional agricultural, horticultural or
agrisilvicultural cultivation systems.
CIP, on-farm conservation of potato germplasm
(www.cipotato.org)

35. In situtechniques
On-farm
Advantages:
1.Dynamic conservation in relation to environmental changes, pest and diseases
2.Ensures the conservation of traditional land races of field crops
3.Ensures the conservation of weedy crop relatives and ancestral forms.
Disadvantages:
1.Vulnerable to changes in farming practices
2.Requires maintenance of traditional cultural systems and possible payment of
premiums to farmers
3.Restricted to field crops
4.Only limited diversity can be maintained on each farm, so multiple farms in diverse
regions are required to ensure the conservation of genetic diversity.

36. In situtechniques
Home garden
•Similar to on-farm conservation, involves smaller scale but more
species-diverse genetic conservation in home, kitchen, backyard or
door-yard gardens.

37. In situtechniques
Home garden
•Advantages:
-Dynamic conservation
-Ensures conservation of traditional land races of minor crops, fruit and
vegetables, medicinal plants, culinary herbs, etc.
-Ensures the conservation of weedy relatives and ancestral forms.
Disadvantages:
-Vulnerable to changes in farming practices
-Appropriate management regimes poorly understood
-Requires maintenance of traditional cultural systems, and possible
subsidization of farmers

38. Utilization of Germplasm
The germplasmcan be used in a breeding programmein the
following 3 ways:
1.Direct release as a variety
2.It may be subjected to selection for developing a variety
3.It may be used as parent in hybridization programme

39. Utilization of
Germplasm Resources
Release of New
Improved Variety
Development of
Genetically Diverse Populations
Vigorous Yield Testing

41. Table . Gene banks of various crops in India
Crop species Location of gene bank centre
Wheat DWR,Karnal(Haryana)
Rice CRRI,Cuttack(Orissa)
Potato CPRI,Shimla(HimachalPradesh)
Cotton CICR,Nagpur(Maharashtra)
Sugarcane SBI,Coimbatore(TamilNadu)
Tobacco CTRI,Rajahmundry(AndhraPradesh)
Pulses IIPR,Kanpur,(UttarPradesh)
ForageCrops IGFRI,Jhansi
PlantationCrops CPCRI,Kasargod,(Kerala)
TuberCrops(exceptPotato) CTCRI,Trivandrum(Kerala)
OilseedCrops DOR,Hyderabad(AndhraPradesh)
HorticulturalCrops IIHR,Bangalore(Karnataka)
Sorghum NRCSorghum,Hyderabad(AndhraPradesh)
Groundnut NRCGroundnut,Junagadh(Gujarat)
Soybean NRCSoybean,Indore(MadhyaPradesh)
Maize IARI,NewDelhi

42. Gene banks maintained by various
International Crop Research Institutions
Location of gene bank Crops maintained
IRRI,Philippines Rice
CIMMYT,Mexico Maize,Wheat,TriticaleandBarley
CIAT,Colombia Cassava,beans,RiceandMaize
IITA,Nigeria Cowpea,Soybean,Limabean,Cassava,Sweet
Potato,yamRiceandMaize
CIP,Peru Potato
ICRISAT,India Sorghum,PearlMillet,Pigeonpea,Chickpea,
Groundnut
ICARDA,Syria Durumwheat,BarleyandBeans
Florida,USDA Sugarcane