How to Feed a Hungry How to Feed a Hungry WorldWorld

World Population LevelsWorld Population Levels

• 6 billion in 19996 billion in 1999• Will probably reach 8 billion by Will probably reach 8 billion by

2020, this will add 2 billion in 20 2020, this will add 2 billion in 20 yearsyears

• A population of 8 billion will A population of 8 billion will present major problems in the present major problems in the production and distribution of production and distribution of sufficient foodsufficient food

Status of HungerStatus of Hunger

• Approximately 1 billion people not Approximately 1 billion people not getting sufficient food todaygetting sufficient food today

• Marasmus and Kwashiorkor are Marasmus and Kwashiorkor are common in developing nationscommon in developing nations

• How can we adequately feed the How can we adequately feed the anticipated 2 billion that will be anticipated 2 billion that will be added to the population?added to the population?

Improvements in Improvements in AgricultureAgriculture

• Improvements in crop yields began early Improvements in crop yields began early in 20th century - as Mendel’s work in 20th century - as Mendel’s work became knownbecame known

• In past 50 yrs US yields continued to In past 50 yrs US yields continued to increase - 3 fold increase since 1940sincrease - 3 fold increase since 1940s– 1940s - corn yields 40 bushels/acre1940s - corn yields 40 bushels/acre– 1990s - corn yields 200 bushels/acre1990s - corn yields 200 bushels/acre

• High yielding varieties at the center of High yielding varieties at the center of this accomplishment -- BUT not alonethis accomplishment -- BUT not alone

High Yield CropsHigh Yield Crops

• Also known as high impact crops and Also known as high impact crops and high responding cropshigh responding crops

• High Impact Crops RequireHigh Impact Crops Require– Excellent growing conditionsExcellent growing conditions– MechanizationMechanization– Fertilizers ---Fertilizers --- may be the most important may be the most important– PesticidesPesticides– IrrigationIrrigation

Green RevolutionGreen Revolution

• After WWII, Rockefeller Foundation After WWII, Rockefeller Foundation and other agencies set up Agricultural and other agencies set up Agricultural Research Stations in tropical areasResearch Stations in tropical areas

• Goal - improve crop production in Goal - improve crop production in developing nations like those in USdeveloping nations like those in US

• Most research initially focused on Most research initially focused on wheat, rice, and corn but potatoes and wheat, rice, and corn but potatoes and cassava research added latercassava research added later

Wheat - Principal Focus of Wheat - Principal Focus of Green RevolutionGreen Revolution

• Father of Green Revolution - Dr. Father of Green Revolution - Dr. Norman Borlaug– Developed high yielding dwarf varieties Developed high yielding dwarf varieties

that take heavy fertilizer without lodgingthat take heavy fertilizer without lodging– By late 1960s food production By late 1960s food production

dramatically increased in many dramatically increased in many developing nationsdeveloping nations

– 1970 - Borlaug awarded Nobel Peace 1970 - Borlaug awarded Nobel Peace Prize “abolish hunger in a few years”Prize “abolish hunger in a few years”

Disease and Pest Disease and Pest ResistanceResistance

• Another aim of the Green RevolutionAnother aim of the Green Revolution• 50% of the world’s crops destroyed 50% of the world’s crops destroyed

in field or in storage due to fungi, in field or in storage due to fungi, bacteria, viruses, nematodes and bacteria, viruses, nematodes and insectsinsects– Insects are chief competitors for human Insects are chief competitors for human

foodfood– Fungi right behindFungi right behind

Ways to Produce Healthy Ways to Produce Healthy PlantsPlants

• ChemicalsChemicals• Biological ControlsBiological Controls• Disease-Resistant Crops - cheapest Disease-Resistant Crops - cheapest

and most effective methodand most effective method– Breeding for disease resistance must Breeding for disease resistance must

be coupled to yield, quality, climate, be coupled to yield, quality, climate, tastetaste

• Integrated Pest Management (IPM)Integrated Pest Management (IPM)

Problems with the Green Problems with the Green RevolutionRevolution: : What went What went

wrong?wrong?• Optimism of the 60s gave way to the Optimism of the 60s gave way to the

realities of 70srealities of 70s– Cost associated with seeds, fertilizer, Cost associated with seeds, fertilizer,

pesticides, irrigation, farm equipment, fuelpesticides, irrigation, farm equipment, fuel– High energy costs - 2 barrels of oil/barrel High energy costs - 2 barrels of oil/barrel

of fertilizerof fertilizer– Environmental damageEnvironmental damage– Loss of genetic diversityLoss of genetic diversity– Whole premise wrongWhole premise wrong

Loss of Genetic DiversityLoss of Genetic Diversity• Modern agriculture based on Modern agriculture based on

monocultures -- disadvantagesmonocultures -- disadvantages• Share vulnerability to diseaseShare vulnerability to disease• Loss of genetic diversityLoss of genetic diversity

• Native varieties are being replacedNative varieties are being replaced• Tropical forests being clearedTropical forests being cleared• Will we have the resources to continue Will we have the resources to continue

developing new varieties?developing new varieties?• Seed banks may help but who owns the genes?Seed banks may help but who owns the genes?

SolutionsSolutions

• Continue along present course - Continue along present course - some researchers believe that we some researchers believe that we are near the maximum potential are near the maximum potential yields for many cropsyields for many crops

• Alternative cropsAlternative crops• BiotechnologyBiotechnology

BiotechnologyBiotechnology

• Use of living organisms to provide Use of living organisms to provide products for humanityproducts for humanity

• Today term often implies the use of Today term often implies the use of genetic engineering to create plants genetic engineering to create plants with new and useful characteristicswith new and useful characteristics

• Intent no different that traditional Intent no different that traditional plant breeding - differs in methods, plant breeding - differs in methods, speed, and possible crossesspeed, and possible crosses

Cell and Tissue CultureCell and Tissue Culture

• Plant cells can be Plant cells can be cultured to get an cultured to get an undifferentiated undifferentiated mass of cells called mass of cells called a callusa callus

• When the right % of When the right % of hormones are added hormones are added to the culture, the to the culture, the callus will develop callus will develop into a plantinto a plant

Mutations in Cell CulturesMutations in Cell Cultures

• Although all cells in culture are clones, Although all cells in culture are clones, sometimes mutations occursometimes mutations occur

• During sexual reproduction, mutations During sexual reproduction, mutations are rare - maybe 1 in 1 millionare rare - maybe 1 in 1 million

• In tissue culture mutation rate much In tissue culture mutation rate much greater - called somaclonal mutantsgreater - called somaclonal mutants

• In one experiment with tomato plants In one experiment with tomato plants from culture 13 mutations in 230 plantsfrom culture 13 mutations in 230 plants

Applications of Cell CultureApplications of Cell Culture

• Somaclonal mutants may have Somaclonal mutants may have useful traitsuseful traits

• Expose tissue culture to certain Expose tissue culture to certain toxins or poisons to find resistant toxins or poisons to find resistant plantsplants– parasite toxins to look for resistanceparasite toxins to look for resistance– herbicides to look for resistanceherbicides to look for resistance

Genetic EngineeringGenetic Engineering

• Genetic EngineeringGenetic Engineering uses the uses the techniques of recombinant DNA to techniques of recombinant DNA to produce transgenic plantsproduce transgenic plants– Recombinant DNA transfers segments transfers segments

of DNA from one organisms to anotherof DNA from one organisms to another– Plants with foreign genes are called Plants with foreign genes are called

transgenic plants– This is possible because all organism use This is possible because all organism use

the same genetic codethe same genetic code

Gene FunctionGene Function

Gene TransferGene Transfer

• Identify gene of interestIdentify gene of interest• Select a vector for transferring the Select a vector for transferring the

genegene• Cut the gene from donor organismCut the gene from donor organism• Transfer gene to vectorTransfer gene to vector• Insert into host organismInsert into host organism

Plasmids Used to Transfer Plasmids Used to Transfer GeneGene

Success of Genetic Success of Genetic EngineeringEngineering

• First successful genetically First successful genetically engineered experiment on a plant engineered experiment on a plant in 1982in 1982

• First crop approved for sale in 1994 First crop approved for sale in 1994 - Flavr-Savr tomato- Flavr-Savr tomato

• Today dozens of genetically Today dozens of genetically engineered crops on the marketengineered crops on the market

• Thousand of field testsThousand of field tests

Genetically Engineered Genetically Engineered PlantsPlants

• Herbicide-resistant soybean, cotton, Herbicide-resistant soybean, cotton, corn, and canolacorn, and canola

• Insect-resistant corn, cotton, potato Insect-resistant corn, cotton, potato have genes for Bt (have genes for Bt (Bacillus Bacillus thuringiensisthuringiensis) toxins) toxins

• Tomatoes with delayed ripeningTomatoes with delayed ripening• Canola with high lauric acid Canola with high lauric acid

productionproduction

ChecksChecks

• Lots of approval required before Lots of approval required before the crops are released in the crops are released in environmentenvironment

• Federal agency approving crops for Federal agency approving crops for marketing marketing – FDAFDA– EPA EPA – USDAUSDA

Environmental ConcernsEnvironmental Concerns

• Can the organism pass on traits in the Can the organism pass on traits in the environment?environment?– Can herbicide resistance spread to Can herbicide resistance spread to

weeds?weeds?

• Can insects become resistant to Bt Can insects become resistant to Bt toxins? toxins?

• Can harmful traits be passed on Can harmful traits be passed on accidentally? Brazil nut allergen in accidentally? Brazil nut allergen in soysoy