Benoit Landry obtained is Ph.D. in 1987 from the University of
California (Davis) where he constructed one of the first
RFLP-based genetic maps in plants (lettuce). Since then, he has
also conducted several important crucifer research programs and
constructed genetic maps of numerous species. Adjunct Professor
at the Department of Biology, McGill University, he has received
international awards and scholarships for his research.
Benoit is the founder of DNA LandMarks and currently oversees
its growth and development as CEO and Managing Director.
For those unfamiliar
with DNA marker technology, can you provide an overview
of what marker-assisted breeding entails?
Marker-assisted breeding
involves the use of DNA markers and detailed genetic maps to
enhance conventional plant breeding efforts. DNA markers are
stretches of DNA with specific nucleotide sequences; the four
letter word alphabet of our genetic code, A C T
and G . Different individuals will exhibit different sequences
of these letters. These differences are called DNA
polymorphisms and they are easily tracked by laboratory
assays. By correlating these polymorphisms to specific traits
in the plant, we can use them to screen individuals from a
cross and tell the breeders which are the best plants to
advance in the breeding program and which should be discarded.
Today we can use genetic
markers to screen for a wide range of performance traits such
as disease resistance, transgenes, specific food production
qualities, etc.
DNA markers are also used more
broadly to fingerprint varieties. These DNA fingerprints are
used to protect against variety infringement, for quality
control (e.g. hybrid purity testing) and for germplasm
characterization which allows breeders to make more informed
crosses in their nursery.
How long has this
technology been around?
Genetic markers and DNA mapping first arose about 20 years
ago. During that period, the DNA marker system being used was
called restriction fragment length polymorphism (RFLP).
Since that time, the technology has evolved greatly. There
are many newer, more efficient marker systems available today
(such as SSR, SNP, IMP) that are custom designed for different
applications. The effectiveness of the technology has
increased many-fold while the cost has become ever more
affordable.
Today, marker-assisted breeding is a very valuable service for
even small to medium sized seed and food companies.
What do you see as the
key benefits of this technology for plant breeders?
There are numerous advantages to marker-assisted breeding:
The first advantage is speed. Markers allow you to screen
breeding material very early in the plant’s life cycle,
usually just after it has sprouted or even on dry seeds.
Therefore, you can see if the plant has a certain trait long
before it might normally express that trait phenotypically.
We have customers that plant their material, send us tissue
from the first few leaves, we provide them genotypes even
before the plants pollinate which allows them to make much
more informed crosses.
The second advantage is the ability to screen for traits that
are difficult to evaluate phenotypically. For example, in
order to tell if a plant has resistance to a specific disease,
you need to make sure the disease is present to infect the
plant. In some cases, this can be a complex and costly
process. However if you screen the plants with DNA markers
closely linked to the disease resistance gene, you can tell
which plants are resistant without having to inoculate with
the pathogen.
Another advantage of DNA marker-assisted breeding is that it
removes environmental variation. Plant breeders know that a
plant’s phenotype will vary depending on the environment in
which it is grown. This variation can make it difficult to
make trait determinations based on phenotypic data. This is
especially true for complex traits such as yield components
and abiotic stresses. With genetic markers, there is no such
variation and many genes can be tracked at the same time.
Evaluations can be made with a much higher degree of
confidence and accuracy.
Finally, marker-assisted breeding provides a tremendous
opportunity for crop improvement on traits that are non-GMO.
The regulatory issues involved with new GMOs are extremely
costly to the extent that many new innovations do not proceed
because the economic hurdle is too high. This is not the case
for marker-assisted breeding, making it a very cost effective
route to creating elite varieties.
Are many companies
using this technology today?
Not that long ago, it was only the biggest seed companies that
could afford to use DNA markers. Usually these were
multi-national companies dealing in the largest acreage field
crops.
Today we are seeing a much broader use. Companies that deal
in smaller crops formed research consortia which helped share
the initial cost of developing and mapping new markers.
Successive innovations have also increased accessibility. We
are now seeing widespread DNA marker use in vegetables, fruit,
trees and many other crops.
Is it difficult and/or
costly to access and utilize this technology?
In a way,
the development of marker technology is similar to the
evolution of computer technology. At first, computers were
cumbersome and expensive – only the largest companies could
afford them. Today computers are tiny, much more powerful and
extremely affordable.
With
marker-assisted breeding, the situation is similar. At first,
only the largest companies (Pioneer, Monsanto) could afford
this technology for the biggest crops (corn, soybean). Today,
new innovations allow us to develop and use markers more
efficiently. This lower cost opens up this technology to a
much broader market. Small to mid-sized companies can afford
to use it to enhance their breeding efforts. Markers can be
developed for smaller acreage crops (vegetables, trees, etc).
This trend will continue as we go forward, it is an inevitable
evolution of the technology. Now, nearly all plant breeding
programs are using DNA markers as part of their R&D.
How large a role with
marker-assisted breeding play in the future?
As the
effectiveness of markers is realized by the industry, it will
play a vital role in the future. Using DNA markers to select
for specific traits is one application we discussed. Another
valuable service is marker-assisted backcrossing.
Traditionally, when breeders try to introgress a specific
trait into a commercial line, they have to make six
backcrosses to recover a reasonable amount of the recurrent
parent genome (sometimes many more if linkage drag is a
problem). Using a wide array of markers, we can recover 97%
of the recurrent parent genome in only two backcross
generations.
Furthermore, new technologies such as SNP and IMP markers will
increase genotyping efficiency, lower the cost and open up
even more applications in the future.
Will this technology
eventually replace conventional plant breeding and plant
breeders?
Definitely not!
Marker-assisted breeding should be used exactly as it reads –
to assist conventional breeding. It would be naïve and wrong
to think we could sit in our lab and create the perfect plant
in a tube.
This
technology should be viewed by the plant breeder simply as a
very powerful tool to help get his/her job done better and be
more successful as a breeder.
What role does DNA
marker-assisted breeding play in relation to genetic
transformation technology?
Genetic
transformation has received the lion’s share of press, both
good and bad. However, both of these technologies are very
powerful tools.
Markers
can be used in conjunction with transgenic traits. In the
case of marker-assisted backcrossing, often the trait that
is being introgressed is a transgene.
One of
the potential advantages that marker-assisted breeding holds
for crop development is its ability to work with multigenic
traits. Many of the most important traits that breeders
look for in plants (yield, drought tolerance, etc) are not
controlled by a single gene. Using QTL (quantitative trait
locus) analysis, it is possible to tackle these more complex
issues with marker-assisted breeding.
As is
usually the case, the greatest benefit will be to use both
technologies (and others) in harmony to create the best
varieties possible.
What would you like
the reader to know about your company?
DNA
LandMarks is a world leader in plant DNA marker and mapping
technology. We have three key strengths that allow us to
provide exceptional service to our customers:
Number
one, our team: We have seven Ph.D. research scientists on
staff, many of whom are pioneers in genetic marker and
mapping technology. They lead our highly trained and
dedicated lab team (numbering 30-35). Together they strive
to deliver high quality, consistent results so that our
customers can make decisions with complete confidence.
Number
two, the breadth of our technology: Today there are a wide
variety of marker systems available. Often labs tend to
focus on one system to the exclusion of others. DNA
LandMarks believes that each system has its key strengths
and that the greatest value comes from using a variety of
markers in combination.
Number
three, our resources: Through our research partnerships
over the years, DNA LandMarks has been able to build a
state-of-the-art, high throughput lab. This is of vital
importance since often our customers have numerous samples
to be screened in a short period of time. We feel it is
crucial that we push our technology to meet the demands of
our customers
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