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Water hyacinth not so bad after all

Sure, the water hyacinth is a terrible weed on Lake Victoria. But, as I blogged last year, it does have some redeeming features, for example it can be used to make furniture. Now comes news that it can also be fed to animals, and that it shelters catfish fingerlings. ((Coincidentally, there was another heartwarming aquaculture piece from Africa in the news today.)) One man’s invasive weed is another woman’s income-earning opportunity. How long before it is officially classed as agrobiodiversity?

LATER: Ok, apologies. A comment alerted me to the fact that I had misread the article, and that hippo grass is not water hyacinth, but rather (probably) Echinochloa stagnina. The perils of common names. But the fact remains that people are making use of a plant that to many is a pest. The dividing line between useful agrobiodiversity and noxious weed can be hard to define. Thank you, Inoculated Mind.

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American farmers got stoned a lot

Two articles this morning both point to the widespread use of hallucinogenic plants in ancient South America. National Geographic reports that traces of the mind-altering substance harmine have been found in the hair of Tiwanaku mummies from the coastal Chilean desert dating back to 800-1200 AD. Harmine comes from the Amazonian vine Banisteriopsis caapi, which suggests that an extensive trade network linked the rainforest to the desert. Elaborate sniffing kits have been found in many Tiwanaku tombs and also, as a Times article points out, at the other end of the continent in the Caribbean. Archaeologists have found ceramic bowls and inhaling tubes on the island of Carriacou and have identified them as originating in South America between 100-400 BC. The drug of choice in this case may have been cohoba.

So why was everyone getting high?

Richard Davenport-Hines, a former history lecturer at the London School of Economics and author of The Pursuit of Oblivion, a global history of narcotics, believes humans have been using drugs for thousands of years. “Drug use became widespread in many early agriculture-based societies simply because it was the only way people could cope with spending long hours working in the fields, often in horrible conditions like baking sun,” he said.

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What is a landrace anyway?

When plant genetic resources people are tired and emotional, and sometimes when they’re not, talk can turn to landraces. What are they? Can they be identified unequivocally? Can they be associated with a geographical location? Are names anything other than a convenient fiction? Whole chapters, if not entire books, have been written on the subject. ((I should know; I wrote one, five years ago, which I’d link to if it had been published.)) There are definitions aplenty, of course, but that’s not the same as an answer.

Wrapped up in the definitions, and the answers, are notions of genetic variability within the landrace population and an element of selection being needed to maintain the landrace’s properties and maybe guide it in new directions. But that, of course, is crucially affected by the breeding biology of the species concerned. Bluntly, species that are reproduced clonally, like figs, say, or potatoes, are unlikely to have any variability within the landrace while those that are obligate outbreeders, such as maize, are going to be much more variable within the population and likely to change over time too. And then there are inbreeders — beans like Phaseolus vulgaris — in which the landrace is probably a mixture of different genetically pretty uniform types, each of which may well breed true, although the proportions of each may vary from season to season and from place to place.

All of which is a long and roundabout introduction to three recent papers in Theoretical and Applied Genetics that tackle the problem of landrace identity, all of them using molecular markers.

Oat (Avena sativa) is normally self-pollinating, but occasional crossing does occur. So we would not expect much variation within a population. Good thing that, because Hermann Buerstmayr and his colleagues sampled DNA from only three individuals in each of 114 oat varieties gathered from around the world. ((Ref to come DOI 10.1007/s00122-008-0843-y))

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Six million and counting

So the Missouri Botanical Garden herbarium reached its 6 millionth specimen. ((Incidentally, that’s about the number of germplasm accessions in all the world’s genebanks, give or take half a million.)) ((And another thing: if you’ve got nice photos of botanic gardens, you can enter them into a competition.)) Pretty impressive, as these things go, and as good an opportunity as any to sing the praises of natural history collections. The specimen in question is Anthurium centimillesimum, a new aroid species from Ecuador. I wonder if it will ever join the ranks of the world’s 35,000 cultivated plants.

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Are species like cans of soup?

A longish article in the latest Wired does what seems to this untutored eye a good job of describing the controversy about barcoding. Here’s the case against in a nutshell:

“We’re not accusing Hebert of being a creationist, just of acting like one,” says Brent Mishler.

and the case for:

The space ship lands. He steps out. He points it around. It says “friendly – unfriendly – edible – poisonous – dangerous – living – inanimate.”

There are a lot of pithy quotes like those and astute observations, such as the one that Charles Darwin was a parataxonomist. Well worth reading. We have, of course, blogged about barcoding before.