Transcript CSI” Plant Style: From Laboratory to your Lunch Tray

“CSI” Plant Style:
From the Laboratory
to the Wheat Field
CAP Grant
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Discover new, valuable, genes and QTLs
Deploy them into adapted varieties around
the country
Use marker-assisted selection strategies
to enhance gene deployment
CAP Grant
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16 institutions around the country
coordinate breeding efforts
4 year grant started in 2006
Over 20 cultivars/germplasm already
released
(http://maswheat.ucdavis.edu)
Impact of Wheat in
Washington In 2006
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Excess of 2.2 million acres planted
 81% winter wheat, 19% spring wheat
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Over 140 million bushels harvested
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Net return of $615 million
From Problem to Lab to Wheat Field
What Traditional Problems
Do We Face
New Characteristics
Needed
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Drought tolerance
Disease and Insect resistance/tolerance
Herbicide resistance/tolerance
High yield
Excellent end-use quality (High GPC)
Definitions
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DNA—Deoxyribo
nucleic acid that
carries the genetic
information in a cell
Gene—a sequence of
DNA that occupies a
specific location and
determines a
particular
characteristic
Definitions
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Allele-one member of a pair of genes that
occupies a specific location on DNA
A=
a=
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= homozygous dominant
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= homozygous recessive
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= heterozygous
Punett Square
Crossing
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Plants are identified which have the trait and
which need the trait
Cross is made to introgress trait
Survivor, no game X Rock-star yielder, dies
10 Seeds (all
)
Self pollination
25 (
) 50 (
) 25 (
)
Crossing
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Cross is made to introgress trait
Survivor, no game X Rock-star yielder, dies
10 Seeds (all
)
Self pollination
25 (
) 50 (
Survivor, Rock-star yielder?
) 25 (
)
How Do We Determine Which
Seeds Carry The Trait We Are
Interested In?
So, which of you plants
are resistant to fungal
diseases?
I am!
I am!
I am!
I am!
I am!
I am!
Definitions
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Molecular Markers—DNA segments that
can be used as flags to track genes
Linkage—occurs when particular genes
are inherited jointly
Linked Markers—markers which are
closely associated with a gene
DNA
Gene
Marker
Gene
We know the DNA sequence of the marker
Sometimes we do not know the sequence of
the gene we are looking for
We can use the marker to indirectly select for
the gene of interest
Tightly Linked Marker
Gene
Marker
Gene
95% confident
Non-linked Marker
Gene
Marker
Gene
50% confident
Marker-Assisted Selection
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Identify marker which is linked to gene
We can extract DNA from the plants and
look for the presence of the marker
This will tell us which have the trait and
which do not
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Picture of harvesting tissue
1
2
3
4
+ 95% Ethanol
PCR Explanation
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Polymerase Chain Reaction
Used to amplify DNA via enzymatic
replication
Allows a small amount of DNA to be used
for analysis
PCR reaction
http://www.danquinnart.com/wheatcap/index.htm
Gel Electrophoresis
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Allows separation of PCR product
DNA inserted into agarose gel
DNA fragments travel with current
Smaller fragments will travel faster than
large fragments
Gel Analysis
Gel Analysis
Gel Analysis
Gel Analysis
Gel Analysis
So, which of you plants
are resistant to fungal
diseases?
Evaluation
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After MAS has identified which plants
carry the trait, further evaluation is done in
the field to make sure the plants are
productive
Time to release a variety is shortened
Why would this be important?
Zak
+ 1 gene
Tara 2002
Trait Selection
Crossing
From Laboratory to Wheat Field
Washington Farmers
Shepherds Grain
WSU Food Services
Acknowledgements