Ho hum … another deadly disease

Science magazine today publishes a paper about mapping the geographical spread of diseases. The key point is that different diseases spread in different ways, and recognising that should make prevention more effective.

It would be possible to run an entire blog on the emergence of diseases. Going well beyond the World Health Organisation’s monitoring systems, and prompted by Larry Brilliant’s TED wish, INSTEDD — International Networked System for Total Early Disease Detection — is starting to move. There are systems for veterinary and food borne diseases, and presumably some for plants too, although they are surprisingly hard to find on the internets. I’d like to read such blogs, but my point here is somewhat different. In a nutshell, agricultural biodiversity is likely to be a source of the solutions, both genetic resistance and as a buffer against disease spread.

In recent months we’ve seen UG99 wheat rust, Asian soybean rust, banana Xanthomonas wilt, cassava brown streak virus and now tomato leaf curl virus hit the headlines. Others too. By the time they make front pages news, these diseases are inevitably accompanied by estimates of the costs they will impose, and these can run into billions of dollars a year. And yet solutions, when they arrive, often go unnoticed. To some extent that’s a function of ADD among news organizations, which have a great deal of difficulty in understanding the process of science and so have very little time for long-term projects. To some extent it is because the solutions themselves often cannot exactly pinpoint specific contributions. A resistant variety may get its characteristics from several parents, as a result of many independent breeding and research efforts. It can be hard to trumpet that as a breakthrough worth stopping the presses for. And such resistant varieties may also take time to prove themselves, which also works against excited news coverage. As for the use of agricultural biodiversity to fight disease, that scarcely gets a mention.

We’ve heard a lot too about the Arctic (Seed) Monkeys and their plans to bury humanity’s global heritage of agricultural biodiversity in the frozen rock of Svalbard, but far less about the basic problem, which is that genebanks and conservation in the wild are starved of committed funding. Everywhere, it seems, people want convincing of the economic value of conserving agricultural biodiversity. At some point, I believe, one has to accept that it will never be possible to specify, in advance, the value of any particular bit of biodiversity. One has to go further and say that the manifest benefits of biodiversity to agriculture in just this one realm of defending our food supply against disease, are so large that the costs, whatever they may be, are trivial by comparison.

If some of those plant diseases caused real pain to the people who control the purse strings, perhaps the value of conservation would become more obvious. For now, I can only hope that agricultural biodiversity coughs up the solutions without too much delay. And when it does, we’ll try to take note here.

p.s. Of course, perhaps the biggest reason to fear disease epidemics relates squarely to human activity — the squandering of antibiotic sensitivity and vastly accelerated travel — which come together gloriously in today’s unfolding saga of the TB patient who took off on the lam. But I mustn’t abuse my position here to wail about those

Skimmed milk cow

A New Zealand biotech company has identified a pretty special mutation in a Friesian cow called Marge. Marge

produces a normal level of protein in her milk but substantially less fat, and the fat she does produce has much more unsaturated fat. She also produces milk with very high levels of omega3 oils.

The trait is heritable, and a commercial herd producing milk that is healthier and butter that is spreadable right out of the fridge is expected to be ready by 2011. The boffins at ViaLactia are looking for the gene involved.

Farmers know best?

A comment on a recent post suggested that one should “start with the assumption that farmers know what is in their best interest.” No doubt that is as true of Indian farmers as the rest of us, but unfortunately in many cases there are other pressures out there that mean that you can’t act on your perceived long-term self-interest, or indeed the information on which you can make that determination is not available or turns out to be faulty. As with the sweetleaf item that started this, we don’t know the full story, so we should be careful not to jump to conclusions, but an article in today’s Hindu newspaper describes a decision by farmers that seems to have gone wrong. Agricultural biodiversity, and its associated knowledge, is an important reason – maybe the most important reason – why unfortunate decisions don’t always result in catastrophe.

Another silver bullet?

The discovery of an enzyme which sits at a crucial step on the metabolic journey from glucose to that important anti-oxidant, vitamin C, opens the way for the kind of silver bullet thinking we have previously been somewhat critical of on this blog. Or it may not. We’ll see.

One of the researchers says:

We now have two strategies to provide enhanced protection against oxidative damage: Stimulate the endogenous activity of the identified enzyme or engineer transgenic plants which overexpress the gene that encodes the enzyme.

But I wonder whether this discovery will also allow the rapid evaluation of cultivars for vitamin C content?

Cotton genetic resources conserved in Texas

You thought Lubbock, Texas was only famous as the birthplace of Buddy Holly? Think again. It’s a veritable hothouse of cotton genetic resources conservation and use. Not much of what you might call news in the Eurekalert piece, but interesting nonetheless. For example, did you know that there are three international cotton germplasm collections, in Lubbock, France and Uzbekistan? Or that breeders are scouring wild cottons for the genes to make the crop more environmentally friendly?