How GM Technology Compares with Other Breeding Techniques
Kevin M. FoltaProfessor and Chairman
Horticultural Sciences Department
kfolta.blogspot.com@kevinfolta
Everyone Loves New Technology
What Plant Genetic Improvement Is
More varieties
Grow better under given conditions
Improved yields
What Plant Genetic Improvement Is
People t hink
Improved yields
Where Do Improved Traits Come From?
Breed it in from a wild population
Directly transfer the related gene(s)(GMO)
Damage DNA with radiation or chemicals; look for good traits
Methods of Plant Genetic Improvement
What are the major ways we genetically improve varieties?Major methodsSome common examplesStrengths / limitations
How do they compare to each other?
The future of plant genetic improvement, barley
How to talk to the public about genetic improvement methods
Dispelling the Naturalistic Fallacy– This is Nothing New!
Remind audiences that genetic improvement of food is a continuum.
Almost none of the plants we regularly consume originated in North America. Almost all were brought here by humans.
None of the food you eat is like its “natural” form
GM technology is simply the most precise version of an age-old practice of breeding and selection.
Humans have always manipulated crop genetics
Inbreeding
Decreases useful production traits
Lower heterozygousity
Non-specific crosses
Combining the desirable traits from two genetic backgrounds into one.
Problem: Linkage drag
Requires many backcosses to “clean up” genetics
Can require a long time
No regulatory issues
X =
IRRI Images
Wide genetic crosses
Integrating traits from wild relatives into elite varieties
Problem: with every “good” gene, you move thousands of “bad” genes.
Solution (+/-) marker-assisted breeding
Marker-Assisted Breeding
Association between the likelihood of inheriting a trait and a certain sequence of DNA
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Marker-Assisted Breeding
Association between the likelihood of inheriting a trait and a certain sequence of DNA
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Wide genetic crosses
North America
Chile
Crossing the Impossible
Bridging Crosses- when the desired cross is not possible, finding a sexually-compatible plant, creating the interspecific hybrid, and then crossing the progeny to the other parental genotype.
Embryo Rescue
Fertilization takes place, but embryo is not viable for normal germination.
If given the proper conditions, the embryo can germinate and mature into a plant.
Hybrids between inbreds
B73 Mo17
Iowa Sate Univ photo
Produce plants from inbreeding that are highly homozygous
Cross two inbreds together and get tremendous heterozygousity
Hybrids between inbreds
Polyploids
Increased numbers of genomes in a cell
Can be natural or induced
Examples:
Beans, potato, strawberry, wheat, brassicas, many others
Polyploids
Increased numbers of genomes in a cell
Seedlessness
Wheat breeding
Mutation Breeding
All genetic variation begins with mutation
Mutations can be induced with ionizing radiation or chemicals
May require backcrossing
High lycopene
Seedlessness
Somatic Fusions
Everything I’ve shown so far is Everything I’ve shown so far is completely acceptable to the completely acceptable to the
public. public.
No labels, no warnings, no No labels, no warnings, no special regulation.special regulation.
Transgenics
What people usually think of as “GMO”
Addition of a gene, or small number of genes
Transgenics
Can add traits from across species (like the Bt gene for insect resistance)
Can suppress traits or viruses using RNAi (as in the papaya and potato)
GM Crops Available Now
9
potato
What are the Three Main Traits?
Virus Resistance
Insect Resistance
Herbicide Resistance
(how the traits work lecture online – (google “ UF biotechnology literacy day”)
Strengths Limitations
Virus resistance Works great, no foreign material
Has cut insecticide use by 10-70%
Saves time, labor, fuel. Allows conservation tillage
Can spread to nonGM populations
Pockets of developing resistance
Resistant weeds are a problem in areas.
Insect resistance
Herbicide resistance
Transgenic Traits May be Stacked into a Single Background
Cisgenics/Intragenics
Transfer of specific genes from the same species
Cis-genic = as-is
Intra-genic = all ‘native’ sequence with some re-arrangement
Cisgenics/Intragenics
Apple Scab
Traditional breeding introduced resistance gene from M. floribunda over 50 years.
Same sequence added by Dutch researchers in <5.
Gene Editing
CRISPR (clustered regularly interspaced short pallindromic repeats)
Targeted, few collateral effects
Allows production of custom mutations
Reasonably fast and efficient
No foreign genes present
GE vs. Traditional Breeding
Wide crosses exchange hundreds or thousands of genes and gene variants; GE moves only one/few.
Traditional breeding frequently uses plants that could never normally cross, GE uses genes from self or any other organism
GE can monitor the effect of a specific change; breeding seeks to judge the effect on plant productivity and does not address possible effects on individual genes.
How can these genetic improvement tools be applied to barley?
A number of traits have relevance to your industry.
-- genes can be added to improve fungal tolerance
-- genes that degrade beta-glucan linkages can be silenced
-- genes can be suppressed to obtain a more compact growth habit
-- genes can be added that will help plants yield consistently during water deficit
-- genes can be added to increase protein content
Talking to public audiences – Get Involved!
Plant genetic improvement techniques are safe.
All methods involve some small risk– but all are about the same risk as traditional breeding.
Techniques that breed in traits can take a long time
Directed changes are more precise and more rapidly available, but frequently require regulatory hurdles
You are the solution.
Farmers are 1.5% of the population, yet are ~0.001% of the presence in social media.
People are interested in food and farming
They look to social media for answers
Farmers consistently are rated as most credible sources of information
You are the solution.
Jennie Schmidt
Brian Scott
Sarah Schultz
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