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Published on August 17th, 2009 | by Steve Savage

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Wheat Breeders: A Quiet Pillar of Sustainable Agriculture

Stem Rust

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I’m doing a series of posts about why wheat has been an orphan crop.  Today I want to talk about UG99 Stem Rust.

In 1999 a new strain of Stem Rust, a severe wheat disease, emerged in Uganda.  It was named UG99, and since then it has spread to other wheat growing areas in Africa and Asia but is expected to spread further.  It is a serious threat to the global human food supply because it causes severe yield losses.

There have been many great articlesblog postings and websites about this important plant disease, so today I will talk about how I think this situation will play out.

I’ll wager that the worst potential from this disease will NOT actually occur. This is not a casual wager – the health or even survival of millions of poor people around the world is at stake.  Some of my wheat breeder friends might not like me to say this (because they legitimately need more funding), but my bet is is still that the breeders will prevail against all odds (and get little credit for it).

I base that qualified optimism on having seen what a remarkable group of scientists called “plant breeders” have been able to achieve in the past.  I’m even more encouraged knowing that they have access to some new tools based on biotechnology.

It Comes Down to Genetics

If you have been reading some of my posts, you might know that I am a supporter of GMO crops.  But in this case, GMO is not the solution that makes the most sense. For many decades, crop resistance to this and other rusts has successfully been achieved with using “conventional breeding,” meaning that the genes were moved around using the regular mechanisms of pollination.  This is not what people label, “genetic engineering,” though it is definitely a form of genetic modification. Wheat rust diseases have mostly been controlled by this sort of “conventional plant breeding” for decades. GMO might well be the best solution for certain other wheat diseases like Fusarium Head Blight, but probably not for rusts.

Just to put things in perspective, very little of the wheat grown in the world today is resistant to this new rust strain.  The little genetic resistance that exists is going to have to be introduced into the hundreds or thousands of cultivars of wheat that are suited to grow in different places and in the many, distinct kinds of wheat.  Then those lines will have to be “back-crossed” to get them restored to the kinds of wheat needed for specific areas and uses.  This is a daunting task to say the least.

So why am I betting on the breeders?

A.  Their track record has been fantastic, even with limited funds

B.  Today it is easier to “introgress” a trait like this using what is called “Marker Assisted Breeding” (a related technology to “DNA finger printing”)

C. As usual, the breeders are cooperating nationally and internationally

D. There are some funds being generated to get this job done (including a big contribution from the Gates Foundation) and hopefully there will be far more

So, is success guaranteed?  No!  It partly depends on how quickly the rust spreads.  That is a function of rain and wind events that are impossible to predict.  It is totally a race between the breeders and nature.

Still, my guess is that wheat breeders, who are low-profile, dedicated scientists, will head-off a potentially disastrous food supply issue in spite of the fact that their funding has been cut more than it should be.  Their success will, in the perverse world of science funding, keep them from being either properly recognized or funded.

Will plant breeders still do their very best to protect the food supply?  Yes, they will.

Images of Stem Rust from the USDA Stem Rust Website



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About the Author

Born in Denver, now living near San Diego. Agricultural scientist for 30+ years with a Ph.D. in Plant Pathology. Have worked for Colorado State University, DuPont and Mycogen and for the last 13 years consulting for all sorts or companies, universities and grower groups. Experience in biological control, natural products, synthetic chemicals, genetics, GMOs and agronomic practices. Have given multiple invited talks on the interaction between agriculture and climate change (both ways)



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