Category: Genetic diversity

Posted on

Growing entrepreneurs in Africa and India

Three fine recent articles all point to ways in which farmers are diversifying their approaches and improving their lives. From East Africa, Catherine Mgendi reports on five years of a project called Enabling Rural Innovation.

“We want to have a developed village with at least one car,” beamed a middle-aged man, drawing cheers from fellow men gathered in the village social hall-cum-church. The women differed, chiding the men for not setting their eyes on more realistic goals such as bicycles.

It’s a long article, full of interesting insights and experience, and well worth reading in its entirety. I managed to fillet this as a kind of summary.

By equipping farmers with essential skills such as organisation and leadership, record keeping, market research and analysis, decision-making, planning and prioritisation, the Eri model empowers subsistence farmers to set their own priorities. These could be new market opportunities for their produce, better prices or the need to develop strategies for mitigating drought/flood-induced famines through diversification, for example. It also opens their eyes to ways of exploiting research and extension support.

From India, news that farmer field schools conducted by the centre for Environment Education have helped farmers in an area of Gujerat move from their traditional crops to more lucrative options that make use of increasing irrigation.

“The cropping pattern has changed with increase in irrigation and wider crop options. Halvad has traditionally been a cotton-growing area. However, with the increase in irrigated area, hybrid cotton has begun to replace older indigenous crops like jowar, bajra and groundnuts. … While the deteriorating water quality has forced farmers to shift to crops that can withstand hard water crop, the raids by wild asses and feral pigs has forced farmers in the vicinity of Little Rann of Kutch to grow crops unpalatable to wild animals.”

If they have water problems now, how long before they cannot grow the new crops and are clamouring for their lost heritage?

And in Ghana, The Economist reports that a new, UK-based chocolate company called Divine Chocolate has cocoa farmers as its largest shareholders. The Economist’s article is behind a paywall, which is why I am linking to Divine’s site and a TV report from Reuters. This one was a real eye-opener to me. As The Economist points out, cocoa farmers worldwide earn about US$4 billion — big bucks except when you consider that global chocolate sales are worth about US$ 75 billion.

The money, in short, is in chocolate–and African farmers are not really in a position to expand into chocolate-making.

Except that they are.

Kuapa Kokoo, Ghana’s largest co-operative, with a membership of 45,000 cocoa growers, owns 45% of Divine and has two seats on its board.

Another astounding fact, from the Reuters report: In Ghana, the average cocoa farmer earns about US$300 a year. US$ 300 is also what the average British family spends on chocolate every year.

The Economist suggests that farmers are increasingly moving upstream to capture value from their efforts.

Other companies are pursuing similar strategies. Agrofair, a tropical-fruit distributor based in the Netherlands, is half-owned by producers. It in turn owns a part of Oké USA, which markets Fairtrade bananas in America. Pachamama, a federated co-operative of Latin American coffee growers, has just completed its first year roasting coffee in America. With the help of in-kind loans of green coffee from its members, the firm has not had to solicit outside investors at all. And Coffee Pacifica, a coffee importer that is publicly traded in America, is one-third owned by the Papua New Guinea Coffee Growers Federation, which represents 120,000 farmers. In 2006 the firm’s sales doubled to almost $3m in America and Europe.

All this, I would venture, should also have a beneficial effect on agricultural biodiversity, but I have no idea whether one could ever demonstrate that impact.

Posted on

Bee immunity

We’ve spent some time on the big bee die off (although not on the mobile phones) as have many other blogs and newspaper articles. In the US, the problem has reached epidemic proportions and has raised serious concerns about the future of several crops that depend to a large degree on bee pollination. Unfortunately recent evidence seems to suggest that the problem, which has been called Colony Collapse Disorder (CCD) has been spotted in Europe, as well. The cause or causes of CCD are unknown, but the list includes the usual suspects ranging from transgenic crops and pathogens to global warming and newly developed pesticides. Oh yes, and cell phones.

So the e-publication of a paper due to appear in the Journal of Heredity ((Variation and Heritability in Immune Gene Expression by Diseased Honeybees. Laura I. Decanini, Anita M. Collins, and Jay D. Evans Journal of Heredity Advance Access published online on April 2, 2007, doi:10.1093/jhered/esm008)) (behind a paywall) is timely. It describes the heritability and genetic variation of a gene called abaecin which is a key component of the immune system of bees.

Bees, like nearly all eukaryotes, have an innate immunity, but are generally thought to lack the additional adaptive immune response, which we and most other vertebrate species have. That is to say insects can’t get the ‘flu and respond by making specific antibodies to the virus (In fairness, the notion that insects do not have an adaptive immune system has been challenged recently by studies in Drosophila. ((Extensive Diversity of Ig-Superfamily Proteins in the Immune System of Insects Fiona L. Watson, Roland Püttmann-Holgado, Franziska Thomas, David L. Lamar, Michael Hughes, Masahiro Kondo, Vivienne I. Rebel, Dietmar Schmucker. Science Vol. 309, pp. 1874 – 1878 DOI: 10.1126/science.1116887 Abstract here.)) )

To find out whether abacein expression differed between bee populations, scientists at the US Department of Agriculture crossed several unrelated males into a homogeneous maternal background and then challenged the offspring with Paenibacillus larvae. This is the bacterium that causes American foulbrood, a widespread larval disease of bees. Subsequent measurements in affected larvae showed that the level of abaecin was moderately heritable but highly variable, differing by as much as 10,000 times between different lines. Why this is variation exists at all is a matter of speculation, but it might be due to selective pressures: an arms race between hosts and different pathogen strains or species.

At any rate an understanding of the components of the immune response in bees at the molecular level and the realization that there appears to exist considerable genetic variation that could be exploited would seem to offer one of the more promising approaches to selection for pathogen resistance. Whether that will stop CCD is anyone’s guess ((From Michael Kubisch)).

Posted on

Lactose tolerance: independent origins and strong selective pressure

Michael Kubisch has submitted another post, based on an article in Nature Genetics. Unfortunately the full article and a News and Views piece about it are behind a paywall. However, I’ve done some sleuthing to find a few links that give more details on the story, which I’ve added at the end. As Michael noted, the article is “not about genetic diversity of agricultural species, but how agriculture has affected human genetic diversity”. That’s good enough for us.

The ability to digest lactose, one of the primary carbohydrates in milk, varies widely among adult human populations. In some European countries nearly 90% of individuals can tolerate lactose, while the incidence in some Asian countries is as low as 1%. The inability to digest lactose is caused by a decline in lactase, the enzyme that breaks down lactose into sugars that can be absorbed into the blood stream. This decline starts shortly after weaning and most likely reflects the fact that until animals were domesticated, milk was simply not a staple of human diets. Lactose tolerance, or lactase persistence as it is sometimes called, in turn is facilitated by a continuous production of lactase throughout adulthood. Not surprisingly, lactase persistence appears to be closely linked to whether a population has traditionally practiced a pastoral or an agricultural lifestyle.

This new study examined the incidence of lactase persistence in several African populations. Based on analysis of genetic markers the authors of the study conclude that the trait appears to have evolved not only independently from Europe, but also more than once in Africa itself. Given that the prevalence of the trait is so high in some populations and domestication of milk-producing animals only goes back 12000 years or so, which is a mere blink of an eye in evolutionary times, milk consumption must have provided a significant benefit for human survival.

Those links:

 

Posted on

More sorghum for Zimbabwe

A press release from the Netherlands Organisation for Scientific Research is creating tiny ripples in the blogosphere because it suggests that fertilizer, rather than water, is what poor farmers in semi-arid regions of Zimbabwe need to improve their crops. That’s certainly one conclusion from the research of Dr Bongani Ncube, who successfully defended her doctoral dissertation 10 days ago. (Congratulations, Bongani.) More important, I think, is the demonstration that almost regardless of water, sorghum crops benefit enormously from a preceding grain legume. There’s an interaction with rainfall to be sure. In a dry year, cowpea yields more than groundnut or bambara groundnut, but sorghum is always better after a nitrogen-fixing legume. That’s not to say that farmers shouldn’t make use of a little artificial fertilizer if they can afford it. But a better strategy might be to grow a variety of grain legumes, to buffer any possible effects of rainfall, and then plant sorghum, using agricultural biodiversity instead of cash to increase the harvest.

Posted on

Cereals databases

Before I disappear for a few days of immersion in the First International Breadfruit Symposium back in Fiji, let me point to two somewhat complementary online resources on cereals genetic resources that I have come across – no doubt Jeremy will say and about time too – in the past couple of days.

The FIGS database brings together passport and evaluation data on bread wheat landraces from a number of the major genebanks and “allows the user to efficiently interrogate the data associated with this collection and provides the capacity to identify custom subsets of accessions with single and multiple trait(s) that may be of importance to breeding programs.” FIGS stands for “Focused Identification of Germplasm Strategy,” and the focus is on identifying material with resistance to abiotic and biotic stresses.

The other database is that of Israel’s Institute of Cereal Crop Improvement, which includes information on accessions of wild cereal relatives collected over the past 30 years. Again, there’s a particular focus on data on disease resistance.