PRT 2008PRT 2008

Lecture 8Lecture 8

Genetic resourcesGenetic resources

Genetic resourcesGenetic resources

Genetic material of actual or Genetic material of actual or potential valuepotential value

GermplasmGermplasm

The term to describe DNA of The term to describe DNA of an organism.an organism.

Genetic materialGenetic material

Any material or plant, animal Any material or plant, animal or microbial containing or microbial containing

functional unit of heredityfunctional unit of heredity

BiodiversityBiodiversity

Variability among living organism. Variability among living organism. It contains 3 aspects – habitat It contains 3 aspects – habitat

biodiversity, genetic biodiversity, biodiversity, genetic biodiversity, species biodiversityspecies biodiversity

Significance of biodiversitySignificance of biodiversity

• It supports the healthy function of It supports the healthy function of the earth’s ecosystemthe earth’s ecosystem

• Without biologically viable world Without biologically viable world human will not existhuman will not exist

• Biodiversity provides services that Biodiversity provides services that maintains life on the earthmaintains life on the earth

• Biodiversity provides human with Biodiversity provides human with esthetic benefitesthetic benefit

Economic benefitEconomic benefit

• CropsCrops

• Domestic animalsDomestic animals

• MedicineMedicine

• Natural products – wild life, fish, Natural products – wild life, fish, timbertimber

• Some 10,000 species of plants and Some 10,000 species of plants and animals are exploited industriallyanimals are exploited industrially

Importance of genetic Importance of genetic resourceresource• Genetics as units of inheritance control Genetics as units of inheritance control

characters in biological organismcharacters in biological organism

• It help increase agricultural production It help increase agricultural production by altering genetic constitution. Rice, by altering genetic constitution. Rice, barley, wheat cotton and sugarcane barley, wheat cotton and sugarcane double. Tomato and rubber triple. Corn, double. Tomato and rubber triple. Corn, sorghum and potato quadruple.sorghum and potato quadruple.

Cont.Cont.

Pest resistance. To maintain Pest resistance. To maintain productivity requires constant productivity requires constant

input of new genetic material to input of new genetic material to overcome crop losses to pest that overcome crop losses to pest that

become pesticide resistant.become pesticide resistant.

Cont.Cont.

Overall crop breeding Overall crop breeding programs add billions to world programs add billions to world

agricultural productionagricultural production

Cont.Cont.

Related to green revolution. Related to green revolution. Norman Borlaug (Nobel Laureate) Norman Borlaug (Nobel Laureate) speculated that by breeding genes speculated that by breeding genes

we can increase productivity.we can increase productivity.

Types of genetic resourcesTypes of genetic resources

• Wild relatives – other species from Wild relatives – other species from the same genus of plant/animalthe same genus of plant/animal

• Weedy relative – bridge between wild Weedy relative – bridge between wild relatives and croprelatives and crop

• Primitive – local typePrimitive – local type

• Modern cultivarsModern cultivars

• Advanced breeding linesAdvanced breeding lines

Where are the genetic Where are the genetic resources?resources?

• Available in areas of diversity – Available in areas of diversity – places where many types of places where many types of biological organism existbiological organism exist

• This is called diversity centers or This is called diversity centers or Diversity hot spots (25 in the world)Diversity hot spots (25 in the world)

Diversity hot spotsDiversity hot spots

• North and central AmericaNorth and central America

• South AmericaSouth America

• Europe and central AsiaEurope and central Asia

• AfricaAfrica

• Mainland AsiaMainland Asia

• Asia PacificAsia Pacific

Center of Plant Center of Plant Origin/DiversityOrigin/Diversity

In an area where high diversity of In an area where high diversity of a particular plant type existed, a particular plant type existed, that area could be the origin of that area could be the origin of

that particular plant. There are 8 that particular plant. There are 8 centers.centers.

Chinese CenterChinese Center

Soybean, Orange, teaSoybean, Orange, tea

Indian CenterIndian Center

Paddy, egg plant, cucumber, Paddy, egg plant, cucumber, pepper, coco yam, banana, pepper, coco yam, banana,

coconutcoconut

Central Asiatic CenterCentral Asiatic Center

Wheat, pea, carrot, appleWheat, pea, carrot, apple

Near Eastern CenterNear Eastern Center

Wheat, barley, melon, grapeWheat, barley, melon, grape

Mediterranean CenterMediterranean Center

Wheat, cabbage, broad beanWheat, cabbage, broad bean

Abyssinian CenterAbyssinian Center

Wheat, barley and coffeeWheat, barley and coffee

South Mexican and Central South Mexican and Central America CenterAmerica Center

Corn, chili, pumpkinCorn, chili, pumpkin

South American CenterSouth American Center

Sweet potato, tomato, potato, Sweet potato, tomato, potato, papaya, tobacco, tapioca, papaya, tobacco, tapioca, groundnut, rubber, cocoa, groundnut, rubber, cocoa,

pineapple pineapple

The demise of the centers of The demise of the centers of originorigin

• Do not always occupy a limited areaDo not always occupy a limited area

• Do not always coincideDo not always coincide

• There are secondary centers due to There are secondary centers due to long history of continuous cultivation, long history of continuous cultivation, ecological diversity, human diversity ecological diversity, human diversity and introgression with wild relativesand introgression with wild relatives

The need for conservationThe need for conservation

• All genetic variation originates from All genetic variation originates from vegetationvegetation

• Mutation are randomMutation are random

• Genetic variation is essential for evolutionGenetic variation is essential for evolution

• Large amount of variation present in Large amount of variation present in natural populationnatural population

SpeciesSpecies

• 1.7 million identified1.7 million identified

• I million are animalsI million are animals

• 250,000 are plants250,000 are plants

• 69,000 and fungi69,000 and fungi

• About 750,000 of the animals are About 750,000 of the animals are insectsinsects

• Each species is given a name – corn Each species is given a name – corn ((Zea mays)Zea mays)

New speciesNew species

About 10,000 are discovered About 10,000 are discovered every yearevery year

Species diversitySpecies diversity

Species are not evenly Species are not evenly distributed. It increases as distributed. It increases as

you moved towards the you moved towards the EquatorEquator

Threat to diversityThreat to diversity

Species are dying due to Species are dying due to multiple causesmultiple causes

CausesCauses

• Natural extinction due to competition and Natural extinction due to competition and natural disastersnatural disasters

• Human intervention causes habitat Human intervention causes habitat destructiondestruction

• Invaded by exotic weedsInvaded by exotic weeds

• Use of modern varieties lead to reduction Use of modern varieties lead to reduction in diversityin diversity

Techniques to conserve genetic Techniques to conserve genetic resourcesresources

• In situ – conservation of important genetic In situ – conservation of important genetic resources in wild population. It is often resources in wild population. It is often associated with traditional subsistence associated with traditional subsistence agriculture.agriculture.

• Ex situ – conservation of genetic resources Ex situ – conservation of genetic resources off-site in gene bank, often in long-term off-site in gene bank, often in long-term storage as seed.storage as seed.