- Hanging out with farmers. Sounds like fun.
- UNEP maps Africa, then and now.
- Small farms are beautiful?
- How sugar changed everything etc etc.
- “Last week, descendants of the early Pueblo nations returned to plant a summer crop of corn, beans and squash, donating some of their traditional seed.” How cool is that?
- Balisca wine at the root of it all.
- California’s farmers waste water — because they have to.
- University of Leeds to spend GBP2.8 million studying poverty, agriculture and nutrition.
- “We have already lost three-quarters of the genetic diversity of agricultural crops.” Right.
Of spears, shields and sorghum
Africa’s farmers have been making sorghum beer for centuries, but it now looks like European brewers are getting in on the act. Heineken and Diageo have started replacing imported barley with locally-grown sorghum in their brewing operations in Ghana and Sierra Leone. It started as a social responsibility project (funded by the Common Fund for Commodities, with the European Co-operative for Rural Development as a partner), but recent increases in the price of malting barley have made it “commercially rather attractive” too.
Of course, farmers have to grow the right variety, and ensure that a consistent supply gets to the breweries, so the project has provided training, access to finance (for seed, fertilizer etc.), and assistance with organizing into groups. This is meant to lead to the establishment of a “sustainable production chain,” which is often touted as a prerequisite for the successful promotion of an underutilized crop — or a crop underutilized for a particular purpose, such as sorghum for industrial brewing: “Farmers need to build confidence that the market is there.”
What will the promotion of a single, industrial use for sorghum do to the diversity of the crop? Nothing good, probably, unless the possible consequences are recognized and appropriate steps taken. In a recent paper we have advocated a “spear and shield” approach to promotion. This means that specific incentives that support diversification should be included when promotion of a particular species, variety or use carries significant risks for (agricultural) biodiversity.
Actions which would support diversification include strengthening community germplasm exchange networks. Coincidentally, there’s an IFPRI discussion paper also out today which looks at the seed system for sorghum and millet in West Africa — Mali, in this case. It seems little certified seed is reaching farmers, though it is still unclear whether this is a demand or supply problem. One of the recommendations is that the formal seed supply systems should deal not only with improved material but also with local landraces. This should be brought to the attention of Heineken, Diageo and their sorghum-brewing partners. Their project should seek to strengthen the local seed system as a whole (the shield), not just help farmers get hold of the preferred brewing variety (the spear).
Genebanks galore
Great to start the day with genebank stories. First, from Africa, two separate articles about the Ugandan genebank, one focusing on what’s going in and the other what’s coming out. And then, from India, a heart-warming story about saving the jackfruit.
A modest proposal
That last but one post of Jeremy’s got me thinking. How do we find out if Arachis ipaensis is still at that locality? I mean, short of mounting a fully-fledged expedition of groundnut experts at vast expense, that is. One way might be to ask a local person to check for us. Ok, a wild peanut species might not be the best thing to try this with, but you get the idea. Problem is, how do we identify a local person who knows that area?
Then I remembered something Jeremy sent me recently. WikiLoc is a website to which you can upload your favourite walk or cycle ride as a GPS track. You can then view all these in a number of different ways, including in Google Earth. So I gbiffed (sensu Cherfas, 2008) the localities of wild Arachis species and viewed them in Google Earth together with all the tracks from South America available on WikiLoc.
Well, of course, none of the trails was anywhere near the locality of A. ipaensis. But I did find others that came near — or very near — the localities of other species. Check this one out, for example:
It’s a 32 km circuit around Piribebuy in Paraguay, and it was uploaded by someone called Yagua. It takes about 4 hours to walk it. And it so happens that a specimen of Arachis glabrata was collected along Yagua’s favourite trail, around its southeastern corner:
Now, I don’t think A. glabrata is a particularly significant component of the groundnut genepool, but say, for the sake of argument, that it had been. Couldn’t we ask Yagua to keep an eye on it for us? Multiply by the more than 10,000 tracks on WikiLoc and pretty soon you’re talking about a real global network of agrobiodiversity monitors. But maybe we should test the idea out with a somewhat more — ahem — charismatic plant. And imagine if germplasm collectors start adding their tracks to WikiLoc.
Soybeans and its bottlenecks (or lack of them)
All too often crop genetic diversity studies — even ones published in peer-reviewed journals –Â are not really testing a clearly set out hypothesis. Markers are chosen and scored for each accession in a germplasm collection, and that’s basically it. Oh sure, estimates of various genetic parameters for the collection as a whole are provided, and there are dendrograms aplenty to illustrate the relationships among accessions. Which is fine, that sort of information can be useful. But one sometimes wishes that more focused questions had been asked — and answered.
Which is why recent work on soybean from USDA and visiting scientists from China and Korea is so interesting. I saw it reported in the February issue of Biodiesel magazine, but the original news item goes back to late last year. What the USDA team did is not just fingerprint material from the 17,000-strong USDA Soybean Germplasm Collection maintained at Urbana, Illinois and publish a nice dendrogram showing how Chinese accessions are related among themselves and to Korean ones, for example. ((Although someone probably did that as well!)) They defined four distinct sets of germplasm, each of which was derived from the one before, and tested the specific hypothesis that each process of derivation caused significant narrowing of genetic diversity, i.e. was associated with a “genetic bottleneck.” The sets of material were:
- 26 accessions of wild soybeansÂ
- 52 Asian landraces derived from them
- the 17 Asian landraces introduced to the US in the 20th century
- 25 elite modern cultivars which have been bred from them
What they found is that genetic diversity (as measured by gene sequencing) in wild soybeans was much greater than in landraces, which is fair enough. Most crops go through a very strong genetic bottleneck at domestication. What was more surprising is that the loss of genetic diversity caused by the introduction of only a few landraces to North America, followed by intensive breeding, amounted to only about 25%. This was much less than expected. The genetic base of US soybeans is narrow, yes, but not that narrow, it turns out.
What this means is that randomly introducing more landraces into soybean breeding programmes will not be very effective. The authors suggest that landraces should instead be carefully selected from the Urbana collection based on what the specific breeding objectives are at any one time. So, if breeding for resistance to the Asian aphid is the aim, landraces from areas of Asia where this pest is found should be the ones to be thawed out of genebank and crossed with the elite material.
All very logical. But I wonder. Was all that gene sequencing really necessary to reach this conclusion? I mean, wouldn’t you want to be somewhat selective in the landraces you introduce into a breeding programme even if the genetic base of the crop had been narrower? Maybe a breeder will help me out here. But anyway, it was good to see a real hypothesis of practical significance clearly set out and tested through specific comparisons in a crop molecular diversity study.