The latest Plant Breeding News is out, though only if you’re registered for email alerts. However, in a couple of days you should be able to get October’s digest on the archive page, where you can also subscribe. Lots of stuff about breeding for climate change in this issue. It’s a great resource, brought to you by the Global Partnership Initiative for Plant Breeding Capacity Building (GIPB). And I’m not just saying that because they gave us a namecheck this month.
Nibbles: Toms, Virus, Svalbard, CIRAD
- More on those purple tomatoes. And there’s lots more where that came from.
- Virus weakens the response of genes that normally boost defense against pest.
- “Superman had it right.”
- Yeah, but France has genebanks too.
- Dispatches from Terra Madre: “How are you fighting racism in your food community?”
Yemen may need taller wheat
Back when I made my living applying an outmoded and discredited paradigm by going around collecting germplasm, I had the great good fortune of visiting the Hardamawt province of what at the time was the People’s Democratic Republic of Yemen. The region, and in particular the beautiful and historic city of Shibam has recently been hit by devastating floods. I could link to news accounts, but I think the series of photographs Jeremy just sent me does a better job of summing up the situation than any number of newspaper articles.
Agriculture in the Hadramawt relies on spate irrigation:
Flood water from mountain catchments is diverted from river beds (wadi’s) and spread over large areas. Spate systems are very risk-prone. The uncertainty comes both from the unpredictable nature of the floods and the frequent changes to the river beds from which the water is diverted.
So flood damage is to be expected every once in a while, and people by and large know how to cope, though on this occasion the flooding seems to have been particularly bad. One of the ways people cope is by building strong houses. Some houses in Shibam are hundreds of years old, despite being made of mud brick. I remember that while collecting (this was 20 years ago) I asked people why they were still growing their local wheats rather than the new Green Revolution varieties. They said that the new varieties, though giving a higher grain yield, were too short, ((In fact, you could say they give higher yields partly because they are shorter.)) and they needed a lot of straw to make the mud bricks they used to build their homes.
Now, I haven’t been back to Shibam since then, and I don’t know whether the use of shorter wheats has spread. And I don’t know whether even if they have this has affected the quality or quantity of the local bricks. But I wonder.
Maize and genetic engineering: why bother?
I was talking to Greg Edmeades tonight. Our conversation coalesced on the topics of the recent posts on maize water stress tolerance and on the usefulness of engineering purple tomatoes.
For many years, Greg led the maize crop physiology group at CIMMYT. He says that one of the main reasons for their success with drought tolerance is their long term institutional commitment to it: 35 years and counting. A particularly impressive feat is the widespread adoption of their maize varieties in southern Africa. For example, ZM623, selected from South African parents by Marianna Bänziger, is grown on about a million ha, says Edmeades.
His take on biotech for drought tolerance is, sure, “use whatever works, but if you are an African agricultural research institute, then, why bother?” Monsanto is reporting 10-15% yield increase under drought stress, and says it will make their technology freely available for use in Africa. Edmeades reckons that you can get a similar yield increase in about 7 years of conventional breeding and selection. And less when using molecular markers. If that is the case, it may not be worth it to deal with the complexities of genetic engineering.
Unless, perhaps, the approaches are entirely additive and you get a combined yield benefit of 30%. I think that’s unlikely. Drought tolerance is about making best use of the available water. It does not increase the amount of water.
Later:
Greg told me that I had been a little harsh in suggesting that he would not advise national programs in Africa to use a transgenic approach to drought tolerance. He would only advice against transgenes if “they had access to a steady stream of good germplasm improved for drought tolerance, and there was no regulatory framework for transgenes in place in that country. If regulatory frameworks exist, and there is no facility of improving their own varieties (or newly released commercial varieties) for drought tolerance in a systematic way, then certainly I’d take the transgenic option, especially since it is being offered on a royalty free basis.”
Purple tomatoes for longer life — if you’re a mouse
I was going to do an in-depth analysis of a paper in tonight’s Nature Biotechnology, but it’s been a busy weekend and there are two press releases out there that do enough of a job on it for my purposes. From one:
Scientists have expressed genes from snapdragon in tomatoes to grow purple tomatoes high in health-protecting anthocyanins. … The scientists tested whether these elevated levels actually had an effect on health. In a pilot test, the lifespan of cancer-susceptible mice was significantly extended when their diet was supplemented with the purple tomatoes compared to supplementation with normal red tomatoes.
Mice given 10% of their diet in the form of powdered, freeze-dried purple tomato lived an average of 182 days, compared to 142 days for mice fed the same amount of freeze-dried red tomato or no supplement, which did not differ from one another. That’s great. Proof of concept, if you like.
From the other:
“The study” says Cathie Martin, FLORA project coordinator “confirms the latest research trends arguing that we can obtain significant beneficial effects by simple changes in our daily diet. We are not talking of pills or supplements but only food. It is worthy of notice that recommendations by worldwide governments risk to be unaccepted. The 5-a-day program promoted by the American National Cancer Institute 20 years ago does not seem to be very incisive and not just because of the lack of time. Financial crisis is giving an hand to the failure of good intentions mainly due to the expensive costs of fruits and vegetables. Research has to do something, has to find new ways to face the challenge. A solution may rely on concentrating in few but selected products the largest part of nutrients we should intake during the whole day”. ((I think this may have been babelfished a couple of times, but that’s not my responsibility.))
Researchers are clearly working hard to put anthocyanin genes into tomatoes, hoping, I suppose, that eventually people will eat those, or freeze-dried anthocyanin-rich genetically-engineered tomato powder, to ward off cancer. I wonder though, why they didn’t start with a naturally purple tomato and attempt to up-regulate the purple pigment genes. Too difficult? There are many such varieties, and I happen to be sensitized to them right now because in connection with something else I came across the Organic Seed Project, which lists “Improvement of Prudens Purple Tomato” as one of its Participatory Plant Breeding projects. Alas, that’s all it does. List it. Anyone know more?
The top photograph, from the research scientists, shows their very purple engineered tomato. The lower one, which has a very bluish cast, suggesting an excess of Photoshopping zeal, shows Prudens Purple in the centre and Black from Tula, a Russian variety, on the right. I’m not aware of any thorough measurements of anthocyanins in tomato varieties, though there is a wild relative with a gene that produces anthocyanin fruit. What is more, it has been conventionally-bred into domesticated tomatoes. We blogged it almost two years ago. ((Although the link that points to is dead and gone.)) I wonder why we have heard no more about it.
My point is not that there’s anything wrong with genetically engineered purple tomatoes. It is that lots of people may think there is. Indeed, and I know I’m going out on a limb here, such a belief may even be more common among those who are most likely to eat food-based dietary supplements to promote good health. So if researchers really want people to eat their tomatoes, why engineer them?