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Undoing millennia of barley selection

Generations of beer-loving farmers have bred seed dormancy almost entirely out of barley, so that the grains will readily germinate in the malthouse. Unfortunately, that means that malting varieties are sometimes prone to jumping the gun and sprouting before harvest, while the crop is still standing in the field. That means that the grain cannot be used to make beer. Not a good thing.

Fortunately, a PhD student in Australia, a land well known for its love of the amber nectar, has compared the barley genome with that of Arabidopsis and identified some bits which may contain previously unknown dormancy genes. Should a negative effect on pre-harvest sprouting be confirmed in the field – and trials are under way – breeders could use markers for these genes to help them select genotypes which will only sprout where it would do the most good: in the maltings.

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Durum wheat erosion

If there’s a dominant meta-narrative in agricultural biodiversity circles it is that modern breeding programmes relentlessly decrease the genetic diversity of crops, increasing yields and quality but also, as new varieties displace landraces and older varieties in farmers’ fields, depleting the very resource on which they are dependent for continued success. But actually there’s not really that much in the way of hard figures on this process. So a recent paper on what breeding has done to diversity in Italian durum wheat is very much to be welcomed.

The researchers used molecular and biochemical markers to compare genetic diversity among five different groups of durum varieties, ranging from landraces from before 1915, to pure lines derived from landraces in the 30s, to genotypes selected from crosses between local material and CIMMYT lines in the 70s. In general, there was indeed a narrowing of the genetic diversity within these groups over time. In fact, the degree of narrowing was probably underestimated, because only a relatively few of the pre-1915 landraces were still available for analysis. Conserving what is left is all the more important.

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Alternative livelihoods

Do wander over to the latest edition of New Agriculturist, which, among other things, has a great feature giving examples of farmers adopting new crops and other ways of making a living as alternatives to illicit, environmentally damaging or otherwise inappropriate ones.

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A prickly question

Carciofi

Dealing with a Carciofo alla Giudea I seldom wrestle also with the more fundamental existential question of what exactly an artichoke is. A flower, of course, although for the most part one is eating bracts and the receptacle. A thistle, too. But beyond that, I have to confess I have never really considered relationships among the various varieties of artichoke nor between the artichoke and its obvious cousin the cardoon (where one eats the blanched petiole, preferably in a tasty bechamel sauce).

Real taxonomists, of course, consider this sort of question all the time. And by and large they have concluded that in the genus Cynara the cultivated artichoke is C. scolymus, with cardoon — wild and cultivated — in a separate species, C. cardunculus. Then again, maybe they all belong to C. cardunculus. And how did they evolve? As crops, artichoke and cardoon are pretty recent, only a couple of thousand years old at most. Which wild species were they selected from?

I need concern myself with these prickly issues no more. A recent paper ((G. Sonnante et al. (2007) On the origin of artichoke and cardoon from the Cynara gene pool as revealed by rDNA sequence variation. Genetic Resources and Crop Evolution 54: 483-495. DOI – 10.1007/s10722-006-9199-9)) from the Institute of Plant Genetics in Bari is clear: artichokes and wild and cultivated cardoons belong to a single species, C. cardunculus. How exactly they evolved is less clear. Cardoon and artichoke were domesticated separately and independently, the artichoke around 2000 years ago and the cardoon 1000 years later “at the beginning of the second millennium AD”. Where all this happened is still mysterious. Artichoke’s origins are probably to the east, while the cardoon was domesticated in northern italy, southern France and Spain. But some of the wild “cardoons” of Spain, which differ considerably from those in the eastern Mediterranean, might be feral artichokes.

All of which is delicious. But beyond knowing more about artichoke and cardoon, these findings should also feed into the rational conservation of the species’ biodiversity, being undertaken thanks to a euros 4 million project in Italy ((For which we thank the photograph above.)).