- Analysis of >1000 single nucleotide polymorphisms in geographically matched samples of landrace and wild barley indicates secondary contact and chromosome-level differences in diversity around domestication genes. They’ve been exchanging genes! Oh, and the site of domestication may be further south.
- Identifying population- and community-level mechanisms of diversity–stability relationships in experimental grasslands. Stability depends on a few dominant species that are out of sync with one another.
- Effective governance of access and benefit-sharing under the Convention on Biological Diversity. Identifies six critical factors that determine the effectiveness of ABS governance.
- Diversity and abundance of arthropods in subtropical rice growing areas in the Brazilian south. They’re abundant! And diverse!
Old specimen is new melon crop wild relative
Taxonomy is not the most glamorous of subjects. Taxonomists who venture to suggest that well-loved Latin names might be changed to reflect new knowledge are roundly denounced. Prefer Latin names over “common” names and you are considered a bit of a dork. But taxonomy matters, becuse only if we know we use the same name for the same thing do we know that we are indeed talking about one thing and not two. And that can have important consequences, not least for plant breeding.
A new paper takes a close look at some old herbarium specimens, originally collected in 1856 by Ferdinand von Mueller. ((Telford, I., Schaefer, H., Greuter, W., & Renner, S. (2011). A new Australian species of Luffa (Cucurbitaceae) and typification of two Australian Cucumis names, all based on specimens collected by Ferdinand Mueller in 1856 PhytoKeys, 5 DOI: 10.3897/phytokeys.5.1395)) Mueller was born in Germany in 1825 and went to Australia in 1845, for his health. There, in addition to being a geographer and physician, he became a prominent botanist. He collected extensively, including a long expedition to northern Australia in 1855-6. There he collected many specimens that turned out to be new to science, including two new melons that he called Cucumis jucundus and C. picrocarpus. The two of them are preserved on this herbarium sheet at Kew.
Fast forward 160 years or so, past a few older taxonomic revisions, and you get to one based on molecular analysis that splits the two previously recognized species of Cucumis in Asia, the Malesian region and Australia into 25 species. By this analysis Australia harbours seven species of Cucumis, five of them new to science. C. picrocarpus is one of the two previously recognized species, and the molecular analysis reveals that it is actually the closest wild relative of the cultivated melon, C. melo.
So what? Quite apart from the necessity to call things by their correct names, cultivated melons are besieged by many economically important pests and diseases. It seems likely that, as so often, resistance will come from a wild relative. Which means it is good to know exactly which plant is the closest wild relative. So what’s the status of C. picrocarpus in the wild? I have no idea, alas. I couldn’t find any entries in GBIF (possibly because they are all subsumed under C. melo) and with Luigi gone temporarily to ground I’m not sure where else to look. It seems a fair bet that it might need protection, although I’d be delighted to be wrong.
Brainfood: Genetic isolation and climate change, Not a Sicilian grape variety, Sicilian oregano, Good wine and climate, Italian landraces, Amazonian isolation, Judging livestock, Endosymbionts and CCD, Herbal barcodes, Finnish barley, Wild pigeonpea, Protected areas, Tree hybrids
- The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape. Climate change bringing formerly genetically isolated populations together, possibly increasing adaptive potential.
- Intra-varietal genetic diversity of the grapevine (Vitis vinifera L.) cultivar ‘Nero d’Avola’ as revealed by microsatellite markers. 15 distinct genetic group among 118 plants from 30 Sicilian vineyards seems quite a lot.
- Emerging cultivation of oregano in Sicily: Sensory evaluation of plants and chemical composition of essential oils. More from Sicily. Wild is best.
- Effect of vineyard-scale climate variability on Pinot noir phenolic composition. Its complicated. But at least Pinot noir is not like Nero d’Avola. Or is it? Oh, crap.
- Landraces in Inland areas of the Basilicata region, Italy: monitoring and perspectives for on farm conservation. “Farmer-maintainers” of landraces tend to be old and isolated. Interesting stratified sampling strategy. Basilicata? They grow horseradish there, don’t they? They do indeed.
- Critical distances: Comparing measures of spatial accessibility in the riverine landscapes of Peruvian Amazonia. GIS-calculated time-based accessibility influences rural livelihoods and land use pressure. And agrobiodiversity? Apply to Basilicata next?
- A morphological assessment system for ‘show quality’ bovine livestock based on image analysis. Image of side of animal fed through neural network almost as good as experts in determining how beautiful the animal is. well there’s a triumph for science.
- Endosymbionts and honey bee colony losses? Something else to add to the list of possible causes of colony collapse disorder.
- Commercial teas highlight plant DNA barcode identification successes and obstacles. About a third of products revealed signatures of stuff that was not listed in the ingredients, but that could be due to a number of reasons.
- What would happen to barley production in Finland if global warming exceeded 4°C? A model-based assessment. Nothing good, surprisingly. Better get some new varieties, I guess.
- Cajanus platycarpus (Benth.) Maesen as the donor of new pigeonpea cytoplasmic male sterile (CMS) system. Gotta love those CWRs.
- Australia’s Stock Route Network: 1. A review of its values and implications for future management. Established for movement of livestock before trucks and trains, but has lots of endangered species and communities. Great value on many fronts, in fact. Needs proper governance though.
- Should forest restoration with natural hybrids be allowed? Yep.
The pros and cons of genetic pollution
Is genetic pollution necessarily a bad thing? Well of course there’s pollution and pollution, and the term is often used to describe what might happen to a crop or its wild relatives when a GM variety of that crop starts to be grown in their proximity. But here I mean the genetic mixing of two previously isolated plant populations. As could happen, for example, when you regenerate two genebank accessions of an outcrossing crop side by side. Or when you cultivate an exotic variety of an agroforestry species near wild stands of the same species. Or when you use seed of a wild species from point A to help restore its numbers at far-away point B. The debate about whether genetic mixing is a good or bad thing for conservation has been going on for a while, of course. It is generally thought to be bad. But by coincidence three papers came across my desk this week which suggest that we should perhaps keep an open mind.
The first paper looks at an annual plant in California, Mimulus laciniatus. ((Sexton, J., Strauss, S., & Rice, K. (2011). Gene flow increases fitness at the warm edge of a species’ range Proceedings of the National Academy of Sciences, 108 (28), 11704-11709 DOI: 10.1073/pnas.1100404108)) The researchers compared the progenies of different kinds of crosses in a common garden experiment to measure their overall fitness. They crossed plants from populations at the centre and at the warm periphery of the distribution of the species in various combinations. The most successful crosses, in terms of lifetime reproductive success, were between plants that came from different edge populations. So in this case, a little bit of pollution is actually a pretty good thing, if it comes from the right place.
The second paper looks at a long-lived woody shrub in Australia, Telopea speciosissima. ((Rossetto M, Thurlby KA, Offord CA, Allen CB, & Weston PH (2011). The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape. BMC evolutionary biology, 11 PMID: 21586178)) There’s a lot of different aspects to the study, but let me focus on just one. The species is found along an altitudinal transect. There is considerable genetic structure along this transect, and a close association between altitude, temperature and flowering time. Altitude influences flowering phenology, differences in which throw up a temporal reproductive barrier between coastal and upland populations, leading to genetic differentiation. But not as much as formerly. The current temperature gradient is much flatter than it used to be at glacial maximum, and this has led to phenological overlap and genetic mixing at intermediate altitudes. What’s happening is a natural version of the centre x edge crosses done artificially in the previous paper. The fitness result? The authors are not sure. Could be good, could be bad. They’re going to set up the experiments to find out.
And finally we have a paper on the use of natural hybrids in forest restoration. ((Frascaria-Lacoste, N., Henry, A., Gérard, P., Bertolino, P., Collin, E., & Fernández-Manjarrés, J. (2011). Should Forest Restoration with Natural Hybrids Be Allowed? Restoration Ecology DOI: 10.1111/j.1526-100X.2011.00804.x)) This really ups the ante. We’re no longer talking about the kinds of intra-specific hybrids found at the admixture front at mid-altitudes in the previous paper, or the progenies of the artificial crosses between populations made in the first. We’re talking about hybrids between related tree species. Genetic pollution squared. The authors point out that “restoration programs rarely use local hybrid individuals if a local species exhibits natural hybridization.” But they think they should.
…our current research based on ecophysiological measures of water-use efficiency under controlled conditions on seedlings from these populations suggest that hybrids deal with drier conditions better than either parental species, a trait that could be important for climate change adaptation.
So, should we be a bit more relaxed about genetic pollution? The debate can only intensify as the need for species and habitat restoration, and perhaps assisted migration, increases with climate change. Perhaps we should start by choosing a less value-laden term for it.
Genebanks at IBC18
So apparently, according to various tweets, Prof. David Mabberley made an impassioned plea for crop wild relatives and genebanks during a panel discussion at the International Botanical Congress in Melbourne earlier today. Will try to find out more.