Dr. Karen MoldenhauerDr. Karen MoldenhauerRice Research and Extension CenterRice Research and Extension Center

Stuttgart, ARStuttgart, AR

The Art of Plant The Art of Plant BreedingBreeding

“ImaginationImagination is more is more important than important than knowledge” knowledge” Albert EinsteinAlbert Einstein

““Plant breeding is a unique science in at Plant breeding is a unique science in at least 2 ways. First, it uses knowledge least 2 ways. First, it uses knowledge and techniques from many basic science and techniques from many basic science areas and second, its contribution to areas and second, its contribution to agricultural progress is measured not agricultural progress is measured not only by information, but also by material only by information, but also by material products such as crop varieties, hybrids, products such as crop varieties, hybrids, cloned, etc.”cloned, etc.”

K. J. Frey 1965K. J. Frey 1965

““Plant breeding, broadly Plant breeding, broadly defined, is the art and science defined, is the art and science of improving the genetic of improving the genetic pattern of plants in relation to pattern of plants in relation to their economic use.”their economic use.” D. C. Smith 1965D. C. Smith 1965

Plant breeding is a team sportPlant breeding is a team sport

Breeders Breeders EconomistsEconomistsGeneticistsGeneticists Soil ScientistsSoil ScientistsMolecular GeneticistsMolecular Geneticists Food ScientistsFood ScientistsPathologistsPathologists Weed ScientistsWeed ScientistsEntomologistsEntomologists PhysiologistsPhysiologistsSystems AgronomistsSystems Agronomists StatisticiansStatisticiansExtension SpecialistsExtension Specialists

PlayersPlayers

Input from:Input from:ProducersProducersConsumersConsumersIndustryIndustry

““Intelligent selection Intelligent selection is imperative to is imperative to success”success”H. M. Beachell, 2001H. M. Beachell, 2001

Selection requires making a Selection requires making a ChoiceChoice

• Parental GermplasmParental Germplasm• Breeding MethodsBreeding Methods• Genotypes for testingGenotypes for testing• Testing ProceduresTesting Procedures• Cultivars ultimately released as varietiesCultivars ultimately released as varieties

Selection Criteria ChangeSelection Criteria Change

• Economic conditions changeEconomic conditions change• Crop management practices changeCrop management practices change• Environmental conditions changeEnvironmental conditions change

Primary Goal of Primary Goal of SelectionSelection

IdentifyIdentifyDesirableDesirableGenotypesGenotypes

Selection Method Depends on:Selection Method Depends on:

• Objectives of the programObjectives of the program• Inheritance patterns of traits to be improvedInheritance patterns of traits to be improved• Germplasm availableGermplasm available• Goals of the programGoals of the program

RICE BREEDING OBJECTIVESRICE BREEDING OBJECTIVES•QualityQuality

-Maintain or improve cooking quality-Maintain or improve cooking quality-Increase grain length-Increase grain length-Minimize chalkiness-Minimize chalkiness-Increase product diversity-Increase product diversity

Specialty riceSpecialty riceNutriceuticalsNutriceuticals

•YieldYield -Higher yields, both rough rice and milling-Higher yields, both rough rice and milling-Plant type-Plant type-Yield and milling stability over environments-Yield and milling stability over environments

RICE BREEDING OBJECTIVESRICE BREEDING OBJECTIVES

•Stress resistanceStress resistance-Biotic-Biotic

Combined disease resistanceCombined disease resistanceNew sources of blast resistanceNew sources of blast resistanceSources of rice stink bug Sources of rice stink bug

resistanceresistance-Abiotic-Abiotic

Cold toleranceCold tolerance•MaturityMaturity•Water ConservationWater Conservation

Germplasm AvailableGermplasm Available

• Genetic variability of the current populationsGenetic variability of the current populations• Variability available from plant introductionsVariability available from plant introductions• Variability from other cooperative programsVariability from other cooperative programs

““Choice of germplasm is a Choice of germplasm is a critical decision in a breeding critical decision in a breeding program that requires program that requires considerable thought; it will considerable thought; it will determine maximum potential determine maximum potential improvement that can be improvement that can be attained via breeding; the attained via breeding; the breeding system will determine breeding system will determine how much of that maximum how much of that maximum potential can be realized .”potential can be realized .” A.R. Hallauer & J. B. Miranda, Fo 1981A.R. Hallauer & J. B. Miranda, Fo 1981

Goals of the programGoals of the program

Breeding populationBreeding population -- -- Maximum variabilityMaximum variabilityA pure line is a heterogeneous population ofA pure line is a heterogeneous population ofhomozygous individualshomozygous individuals

Genetics population - limit variabilityGenetics population - limit variability A pure line needs to be created from 1 male A pure line needs to be created from 1 male and 1 female.and 1 female.

Breeding ProceduresBreeding Procedures• PedigreePedigree• Backcrossing & Forward crossingBackcrossing & Forward crossing• Recurrent selectionRecurrent selection• Induced mutationInduced mutation• Single seed descentSingle seed descent• Bulk selectionBulk selection• Mass selectionMass selection

Breeding Program Breeding Program ObjectivesObjectives

Short- intermediate- andShort- intermediate- andlong-term goalslong-term goals

Short Term GoalShort Term Goal

Cultivar DevelopmentCultivar Development

Intermediate GoalsIntermediate Goals

Developing PotentialDeveloping PotentialMaterials for the futureMaterials for the future

Long Term GoalsLong Term Goals

Creating populations andCreating populations andGenetic ConservationGenetic Conservation

Genetic Gains are Genetic Gains are also made in also made in conjunction with conjunction with improvements in improvements in managementmanagement..

Average Rice Yields for Arkansas

020406080

100120140160180

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

Gra

in Y

ield

(lbs

/a)

*Record state Yield of 6910 lbs/a (154 bu/a) in 20044th consecutive year for new record

GeneticGenetic

VariabilityVariability

Simple Screens Simple Screens for Traits of for Traits of

InterestInterest

The act of visually The act of visually selecting desirable selecting desirable plants remains a plants remains a part of plant part of plant breeding today.breeding today.

Success in plant Success in plant breeding hinges on breeding hinges on ability to integrate ability to integrate information from all information from all disciplinesdisciplines

Parental Parental Selection Based Selection Based

on Geneticson Genetics

A model plant type in A model plant type in terms of morphological terms of morphological and physiological and physiological characters.characters.W. R. Fehr 1987, Rasmusson and Gengenbach 1983W. R. Fehr 1987, Rasmusson and Gengenbach 1983

IdeotypeIdeotype

Art of Plant BreedingArt of Plant Breeding

• College CoursesCollege Courses• Scientific LiteratureScientific Literature• CommunicationsCommunications• ExperimentsExperiments• ObservationsObservations• ExperienceExperience

““Sight is a Sight is a faculty; seeing is faculty; seeing is an art”an art”George Perkins MarshGeorge Perkins Marsh

““Tenacity – a personal trait of the Tenacity – a personal trait of the individual scientist who is sometimes individual scientist who is sometimes guided only by his own convictions guided only by his own convictions and conceptions in the “art” of and conceptions in the “art” of breeding. After gathering insights breeding. After gathering insights and experiences from as many and experiences from as many sources as possible the designer or sources as possible the designer or architect may have to forego the architect may have to forego the support of his team and fashion his support of his team and fashion his work with his own vision and work with his own vision and intuition.”intuition.”

H. M. Beachell 2001H. M. Beachell 2001

““Once a dog always a Once a dog always a dog. If you don’t like a dog. If you don’t like a line at some point in the line at some point in the process, don’t question process, don’t question your decision at a later your decision at a later date, throw it out.”date, throw it out.” W. R. FehrW. R. Fehr

““The wider the range of The wider the range of conditions investigated in the conditions investigated in the experiments, the greater is experiments, the greater is the confidence we have in the the confidence we have in the extrapolation of the extrapolation of the conclusions.”conclusions.”

D. R. Cox 1958D. R. Cox 1958

Newbonnet – cross 1968; released 1983; Newbonnet – cross 1968; released 1983; certified seed 1985 = 17 yearscertified seed 1985 = 17 years

Katy - cross 1979; released 1989; certified Katy - cross 1979; released 1989; certified seed 1991 = 12 yearsseed 1991 = 12 years

LaGrue - cross 1985; released 1993;certified LaGrue - cross 1985; released 1993;certified seed 1995 = 10 yearsseed 1995 = 10 years

Wells - cross 1989; released 1999; certified Wells - cross 1989; released 1999; certified seed 2001 = 12 yearsseed 2001 = 12 years

Time Required to Time Required to make a Varietymake a Variety

Marker assisted Marker assisted selection is not a selection is not a time reducing time reducing tool but an tool but an accuracy and accuracy and efficiency tool.efficiency tool.

What are your What are your goals for the goals for the

future?future?

““We need to anticipate future We need to anticipate future needs and strive for goals not needs and strive for goals not easily pictured by others – far-easily pictured by others – far-sightedness and tolerance of sightedness and tolerance of uncertainty are useful uncertainty are useful attributes – long term attributes – long term commitment and patience are commitment and patience are required.” required.”

H. M. Beachell 2001H. M. Beachell 2001

““We have not We have not found the found the best way to best way to do anything”do anything”G.W. Burton 1979G.W. Burton 1979

Plant Breeding Plant Breeding is a numbers is a numbers

gamegame

““If yield is important, and If yield is important, and it usually is, few tools are it usually is, few tools are as efficient as the trained as efficient as the trained eye for selecting the eye for selecting the better plants among better plants among thousands ofthousands of individuals”individuals”

G.W. Burton 1979G.W. Burton 1979

My ideal plant typeMy ideal plant type

Seedling vigorSeedling vigor Dark green Dark green Stiff strawedStiff strawed Stay greenStay greenErect plantErect plant Intermediate width leavesIntermediate width leavesErect leavesErect leaves None to slight awningNone to slight awningLarge panicleLarge panicle 95-100 cm height95-100 cm heightCompact – intermediateCompact – intermediate 100-125 days to maturity100-125 days to maturitySize and shape of grainSize and shape of grainSecondary branchingSecondary branchingSome tillersSome tillers

Is subjective & includes:Is subjective & includes:

PhenotypePhenotype

““Biotech won’t Biotech won’t soon replace soon replace

“conventional” “conventional” breeding” breeding”

David Mackill in David Mackill in Rice Today 2003Rice Today 2003

Quote from Planning of Experiments Dr. D.R. Quote from Planning of Experiments Dr. D.R. Cox 1958Cox 1958“ “ Spratt-Acher barley was almost Spratt-Acher barley was almost everywhere a great success; yet in one everywhere a great success; yet in one district the farmers refused to grow it, district the farmers refused to grow it, alleging that their own race of barley was alleging that their own race of barley was superior. After some time the Department superior. After some time the Department of Agriculture, to demonstrate Spratt-Acher’s of Agriculture, to demonstrate Spratt-Acher’s superiority, produced a single line culture of superiority, produced a single line culture of the native barley and tested it against the the native barley and tested it against the Spratt-Acher in the district in question. –- Spratt-Acher in the district in question. –- The farmers were perfectly right: the native The farmers were perfectly right: the native barley gave the higherbarley gave the higher

yield. –The barley in question grew more yield. –The barley in question grew more and was able to smother the weeds, which and was able to smother the weeds, which flourished in the area; Spratt-Acher – was flourished in the area; Spratt-Acher – was the victim of the weeds. Thus, the original the victim of the weeds. Thus, the original experiments, carried out on well-farmed experiments, carried out on well-farmed land, were definitely misleading when their land, were definitely misleading when their conclusions were applied elsewhere.”conclusions were applied elsewhere.”

““When one When one starts tugging at starts tugging at a single thing in a single thing in nature he finds nature he finds it attachedit attached to to the rest of the the rest of the world”world”John MuirJohn Muir