Category: Genetic diversity

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Cherry blossom on the move

Andy Jarvis writes:
We’ve long known that climate change is shifting the seasons, and plants appear to be flowering earlier in spring. But a recent study of flowering in 17 species and varieties of cherry trees in Japan had some interesting results that highlight the value of agricultural biodiversity. ((Abraham J. Miller-Rushing et al. (2007), Impact of global warming on a group of related species and their hybrids: cherry tree (Rosaceae) flowering at Mt. Takao, Japan. American Journal of Botany 94:1470-1478.)) The authors have observed that cherry trees on average flower 5.5 days earlier today compared with 25 years ago, and attribute this to an increase in temperature of 1.8°C in February-March. Another example of changing phenology. But what is most interesting is the divergent response between varieties and species – some are flowering 3-5 days earlier per 1°C temperature change, while others as many as 9 days earlier per degree change. Interestingly, these are traits that required climate change to express themselves, and must have impacts on production in addition to the aesthetics of the entire mountain no longer flowering at once.

There must be other places where blossom is important that have long term records like this.

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Cutting down on cow emissions

Methane is a powerful greenhouse gas and ruminant farm animals belch out a huge amount of the stuff. No wonder people are scouring agrobiodiversity for animal feeds that minimise emissions. A paper in Animal Feed Science and Technology ((C.R. Soliva, A.B. Zeleke, C. Clement, H.D. Hess, V. Fievez and M. Kreuzer. In vitro screening of various tropical foliages, seeds, fruits and medicinal plants for low methane and high ammonia generating potentials in the rumen. Animal Feed Science and Technology. Corrected Proof, Available online 18 October 2007. http://dx.doi.org/10.1016/j.anifeedsci.2007.09.009)) has come up trumps. The researchers found differences in methane production not just among tropical feed species, but also among accessions of Acacia angustissima and Sesbania sesban. Something to add to the list of evaluation descriptors.

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On the ground in West Bengal

In West Bengal, a penniless activist is preserving 542 local varieties of rice on a teeny farm. It’s an amazing story, as Josh Kearns tells it. He visited Debal Deb’s research station and blogged about it here.

Folk traditions that were widely practiced until just a few generations ago, such as valuing seeds in non-monetary terms and freely sharing resources, have been sacrificed under market culture. Since Debal gives his seeds away for free, he runs the risk of their not being appropriately valued; whereas, if a farmer takes out a huge loan to buy Monsanto’s HYV seeds and they fail to produce a satisfactory yield (or fail altogether, which happens frequently), he blames himself for being a lousy farmer rather than Monsanto for ripping him off.

Just one of the problems of taking care of crop biodiversity outside the mainstream. Kearns does not say that Deb is no ordinary agroconservationist. He’s a friend of a friend, as it happens, and has a PhD from Calcutta University and several published papers and a book to his name.

Still, Kearns reports that against the odds, Debal Deb is succeeding. And while that is good news, I do wonder what the next stage is. OK, so he and his crew are conserving and describing the varieties (to forestall a rights-grab). But there must be ways both to support that work and to make use of the biodiversity to improve lives.

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Apple Day

Yesterday was Apple Day in the UK. Started ages ago ((We don’t need no stinkin’ research.)) by Common Ground to draw attention to the diversity of apples and the threats to their existence, it has grown in a great bowlful of treats around this time. Of course, it’s a bit late now, but here’s a Top Ten of orchards to visit. And a week ago, the Daily Telegraph was visiting Brogdale, waxing lyrical but making very little fuss about the impending sale of the collection.

I miss my apple trees.

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Reinventing the wheel

More evidence of multiple independent domestication events. Previous work has shown such a pattern for rice in Asia and cucurbits in the America. Now it’s the turn of barley in Eurasia. A paper just out ((Saisho, Daisuke, Purugganan, Michael. (2007) Molecular phylogeography of domesticated barley traces expansion of agriculture in the Old World. Genetics.)) looked at both sequences of 5 genes and also morphological traits in a geographically widespread set of 250-odd landraces. ((From a Japanese university genebank.))

The results suggest that the crop was first domesticated 10,000 years ago somewhere in the Fertile Crescent, from whence it spread to Europe, North Africa and Ethiopia (the material from Ethiopia was somewhat distinct, as has already been documented). However, there was apparently also a second domestication, much later. It occurred in the region encompassing southern Central Asia, the eastern Iranian plataeau and the edge of the Indian subcontinent, and it is material from here that spread eastward starting maybe 2,500 years ago, possibly along the Silk Road, to give rise to the barleys of India, the Himalayas and China.

This is not an unusual pattern in Eurasian agricultural biodiversity. Sheep and cattle DNA data also show “two highly divergent lineages that distinguish European and Asian types, indicating a second independent evolution of these livestock species outside the Near East.” Not unusual, but somewhat puzzling. As the barley authors conclude:

It remains unclear why different cultures sought to re-invent these domesticated species several times rather than simply obtain them through diffusion from other farming societies.

The authors of the barley study speculate that the second domestication happened either because of the transmission of knowledge, or as an independent innovation. I find the second option a bit hard to take. Could it be that the results of the first domestication effort were just not adapted to conditions outside the Fertile Crescent, or there was a barrier to their diffusion? Or maybe it was just a matter of pride for the inhabitants of the Iranian plateau to have their own agrobiodiversity?