Policy

January 12, 2010April 19, 2010

Breeders not so bad after all

It is generally thought that continuous selection among crosses of genetically related cultivars has led to a narrowing of the genetic base of the crops on which modern agriculture is based, contributing to the genetic erosion of the crop gene pools on which breeding is based.

But this may be another faulty meta-narrative. At least that’s what a group of researchers from the Dutch genebank say, as a result of a meta-analysis of 44 genetic diversity studies of the varieties of 8 crops released in successive decades. ((Wouw, M., Hintum, T., Kik, C., Treuren, R., & Visser, B. (2010). Genetic diversity trends in twentieth century crop cultivars: a meta analysis Theoretical and Applied Genetics DOI: 10.1007/s00122-009-1252-6)) This is the result:

The meta analysis demonstrated that overall in the long run no substantial reduction in the regional diversity of crop varieties released by plant breeders has taken place.

Of course, that says nothing about the relative frequency at which these varieties have been grown by farmers, also an important aspect of overall diversity, along with how different the varieties are. Anyway, that decrease in the 60’s was only about 6%, and that has been reversed since then. How? Because of genebanks, say the authors.

In the 1960s and 1970s the introduction of the new Green Revolution-type cultivars for the major staple crops led to concerns on the disappearance of the world’s varietal wealth of crop plants. The widely shared concerns ultimately resulted in the establishment of a worldwide network of international genebanks hosted by the CGIAR research centres. The seed samples stored in these genebanks facilitated access of the world’s crop diversity to plant breeders world wide. It seems likely that the easy access to crop diversity provided by the genebanks, improved communication among breeders and easier exchange of seeds were factors contributing to the reversal of the initial trend in diversity reduction as observed in this meta analysis. Also the increased use of crop wild relatives for breeding and in recent years the use of synthetic wheats will have contributed to the observed diversity increase.

Well, it will be interesting to see, in due course, whether the restrictions on access which followed the Convention on Biological Diversity, had an effect, and whether the International Treaty on PGRFA eventually set the world to rights. As it was designed to do.

January 10, 2010January 10, 2010

EU Council conclusions on international biodiversity beyond 2010

6. ACKNOWLEDGES that agrobiodiversity is an important element of biodiversity with significant potential for improving global food security and for climate change mitigation and adaptation, INVITES Member States and the Commission to promote research and capacity development for the sustainable use of agrobiodiversity and ENCOURAGES Member States and the Commission to implement and further strengthen the ITPGRFA;

Interesting.

January 8, 2010June 23, 2017

Indigenous vs exotic trees in Kenya

I promised to reveal a silver lining to the black cloud of my mother-in-law’s forced felling of part of the eucalypt plantation she’s been tending and coppicing forever, her main source of firewood, so here goes. The sight of the newly bare patch of land made her start looking around for a source of seedlings for replanting, and a coincidental visit by some old friends of mine got her thinking that maybe she should go indigenous. At least partly, anyway. Eucalypts are too fast-growing to give up altogether. Her visitors were Lex Thomson and Randy Thaman, who I worked with in the Pacific, and were in Kenya for the International Agroforestry Congress. They noticed a few Prunus africana trees around her place, and told her about its potential. Lex has since left a comment about this on an earlier blog post of mine.

Anyway, after some searching around, Hilda (for that is her name) came across Mr Douglas Ndirangu Kirichu’s nursery at a place called Lari Forest Station in Uplands Division, a short drive along a passable dirt road from her farm. Mr Kirichu runs the Kimotu Environmental Group. He has about a hundred people who collect seeds from the surrounding forest, which he then raises to seedlings and sells, for KSh 30 each (that’s about USD 0.50). Apparently there’s a law that a community can only graze their animals in the forest if they also have a nursery raising indigenous tree seedlings for replanting. So that’s what Mr Kirichu’s group does. To the tune of about 30,000 seedlings when we visited him. ((Oh, and thanks to Hilda’s daughter Linda for taking the notes during our visit.))

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In addition to Prunus africana (mueri in Kikuyu), Mr Kirichu (that’s him on the left in the picture below) also has muna (Aningeria), mutamayo (Olea), mukoe (Dombeya), pondo and mukima (not sure what these are — maybe someone out there can help me?).

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So we bought a couple of each, of course. And Hilda got a dozen mueri to start off her plantation.

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And we planted them both up at the farm (thanks, GK!) and down in Nairobi. Maybe that made the holiday carbon neutral?

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January 7, 2010January 8, 2010

Re-inventing the genebank. Not.

Jeffrey Walck and Kingsley Dixon ((Who are respectively at the Department of Biology, Middle Tennessee State University, Murfreesboro, Tennessee and at the School of Plant Biology, University of Western Australia, West Perth.)) have a piece on genebanks in December’s Nature entitled “Time to future-proof plants in storage.” ((Walck, J., & Dixon, K. (2009). Time to future-proof plants in storage Nature, 462 (7274), 721-721 DOI: 10.1038/462721a)) It says some important things, but in a way that suggests that nobody has thought of them before, or has done anything about it, which I think needs to be countered. ((I wont say anything here about the lumping together of the Millennium Seed Bank at Kew and the Svalbard Global Seed Vault, which is just plain silly.)) The article is behind a paywall, alas.

Here’s the crux of Walck and Dixon’s beef.

At low temperatures, seeds can remain viable for hundreds if not thousands of years. Herein lies the problem: such seeds are literally frozen in time, a snapshot of the genetic diversity of a species at a particular point. Attempts to revive a seed in future habitats very different from those in which it developed could be doomed to failure. A germinating seed is genetically programmed to respond to a precise interplay of temperature and moisture that determines the climatic conditions in which it can best develop. In an environment that lacks the right temperature and moisture balance — which is likely to be disrupted by climate change — a seed will either fail to germinate or the seedling will perish soon afterwards (see Fig. 1).

What are their suggestions for getting around this problem? Here’s a summary:

1. Harvest as much genetic diversity as possible, including at the edge of species ranges, and at different points in time. And harvest large quantities of seed whenever possible.

2. Screen the plants for their adaptation to different environments. “For instance, subjecting seedlings to increased temperatures could allow the selection of those with higher heat tolerance.”

alter the home range of a species

4. “Policy-makers must get involved too: a comprehensive international agreement is required to coordinate the collection of genetic material, particularly for cross-border wild species.”

So, that would be collect properly, evaluate, match seeds to environments and put in place an international policy infrastructure. Doh! I really can’t see anything in that list that genebanks are not already trying to do. Can you? Maybe they’re not doing it as well as they might, and certainly the policy environment is still not ideal, but there’s surely nothing particularly new about these recommendations. Sure, it is always useful to remind a community about best practices, but it would have been nice to point out that genebank managers around the world know what these are, and are in fact trying to follow them.

If they had wanted to suggest something that isn’t already in place, why didn’t they mention the pressing need for a comprehensive global information system? Now that would be an improvement. And yes, we — and they — are working on it.

January 7, 2010

Millions Fed

That’s the title of an IFPRI project funded by the Gates Foundation which aims to document success stories in agricultural development. We mentioned it here before, when it was just being launched. There are a couple of agrobiodiversity examples among the case studies, including maize in Africa, mungbean in Asia and diet diversification in Bangladesh.