Category: Genetic diversity

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The horse in Mongolian culture

They may be trying to develop and diversify their agriculture now (well, since the 1950s), but Mongolians are traditionally very much a nomadic herding culture, with the horse at its centre. ((Though that doesn’t stop them growing small patches of wheat around their temporary encampments, out west in the Altai Mountains.)) One expression of that is how early kids learn to ride.

Most young Mongolians — boys in particular — learn to ride from a very young age. They will then help their fathers with the herding of goats, sheep and horses. Some children have a chance to ride at festivals called Naadam — the biggest of which is held on 11th-13th July in Ulaanbaatar — though there are naadams held throughout the year all over the countryside. Young jockeys between the age of 5 and 12 (girls and boys) race horses over distances ranging from 15km to 30km. There are 6 categories for the races depending on the horses’ age, including a category for 1 year old horses (daag) and one for stallions (azarag).

Selling ayrag
Unfortunately I just missed the celebrations during my recent visit, but I did see lots of kids riding the sturdy local pony, and recordings of last year’s Naadam races were shown every night on TV, along with old wrestling matches. The Mongolian horse predictably has a long and storied history. And diverse uses. For example, there is fermented mare’s milk (ayrag) in the market, and in some restaurants. This time of the summer is the season for it, and you can see signs advertising its sale all along the main roads out in the countryside. I found it very refreshing, with a more defined taste than its camel counterpart.

The horse meat counter
And of course eating horse meat is common, with a separate section in the market, and some specialized dishes.

Alas, this museum display is as close as I got to seeing the famous Mongolian Wild Horse or Przewalski’s Horse (Equus ferus przewalskii), locally known as takhi.

It’s possibly the “closest living wild relative of the domesticated horse, Equus caballus.” Certainly it is genetically very close to the local domesticated breed based on molecular markers, though that could be because of interbreeding. Last seen in the wild in 1969, its restoration in China and Mongolia from captive stock, for example to the Hustain Nuruu National Conservation Park, is one of the great conservation success stories.

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Unbottling the lentil

ResearchBlogging.orgIt is well known that crops go through a genetic bottleneck at domestication. Due to the founder effect, they typically show a fraction of the genetic diversity found in their wild relatives. Which is bad, but fixable: fixing it is the plant breeder’s job — or part of it anyway. What’s less well known, according to a recent paper on lentils by Willy Erskine and co-authors in GRACE, is that the movement of a crop around the world can also often lead to bottlenecks. ((Erskine, W., Sarker, A., & Ashraf, M. (2010). Reconstructing an ancient bottleneck of the movement of the lentil (Lens culinaris ssp. culinaris) into South Asia Genetic Resources and Crop Evolution DOI: 10.1007/s10722-010-9582-4))

Lentil cultivation moved from Afghanistan into the Indo-Gangetic Plain sometime between 7000 and 4000 BC. The authors “reconstructed” this movement by growing random subsets of the ICARDA world lentil collection at two sites, Islamabad and Faisalabad, in Pakistan. Faisalabad is typical of conditions in the Plain, Islamabad is a transitional, mid-altitude environment.

They found that most Afghani accessions did not flower in Islamabad before the local material matured, due to a combination of temperature and photoperiod, the main determinants of flowering in lentils. The few that did were among the most late-flowering in the world. This is probably related to the shift in sowing from winter to spring as lentils moved from their area of origin in lowland SE Turkey and N Syria into the central Asian plateau. The data from Faisalabad in addition showed that every week’s delay in flowering resulted in a 9% loss of yield potential in the lowlands.

So there was strong selection for reduced sensitivity to photoperiod and a return to early flowering as the lentil moved into the Indo-Gangetic Plain, and consequently a genetic bottleneck. ((Incidentally, I am told by Jacob that a genetic bottleneck related to flowering time (earliness) also occurs in the Northern flint maize varieties in the US and Canada.)) But in a way the surprising thing is that there was no cork in the bottle. Where did the genetic variation that allowed adaptation to the Plain come from? The authors note that time to flower in lentils is controlled by both single gene and polygenic systems, and that early flowering is always recessive. Those recessive alleles for early flowering, which may have come from introgression from a wild relative in Afghanistan, must have occasionally come together and been selected for at mid-altitudes, which then “allowed selection for a radically earlier flowering habit as a new adaptive peak for the novel environment of the Indo-Gangetic Plain.”

The challenge is now for breeders to use these insights to broaden the genetic base of the crop in India, where lentil germplasm “is among the least variable among lentil-producing countries for agro-morphological traits … despite its vast area of cultivation there today.”

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Nibbles: FAOSTAT, Drought, Seeds, Helianthus, Coffee trade, CePaCT, Figs, Old rice and new pigeonpea, Navajo tea, Cattle diversity, Diabetes, Art, Aurochs, Cocks

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Livestock genomes not enough

You may remember we nibbled a Science paper entitled Time to Tap Africa’s Livestock Genomes which got a lot of traction in the press a few weeks ago. It has also generated an interesting discussion at the DAD-Net forum, set off by the following contribution by Dr Ilse Köhler-Rollefson of the League for Pastoral Peoples and Endogenous Livestock Development, which she has kindly allowed us to reproduce here.

Congratulations on this article – it is certainly great to have these issues raised in a high profile scientific journal! However, after reading the summary about it presented in the BBC interview, I am a bit worried about the notion of the need to “tap Africa’s animal genetic resources” before they have become extinct. For one, they are already being “tapped” by African pastoralists — and have been tapped for hundreds or thousands of years — to enable survival in inhospitable areas. One crucial aspect of pastoralist livestock is the ability to walk for ever and thereby access and then ingest and metabolize vegetation that would otherwise be of no use to humans. Their contribution to food security is thus enormous. Unfortunately, to my knowledge, no scientific research has ever focused on “walkability.”

But what we urgently need to realise is that many of the wonderful characteristics of African and other pastoralist livestock are not a question of genetics, but of learned behaviour, as Saverio Kraetli has shown in his seminal studies of WoDaaBe cattle breeders in Niger. It is therefore a fallacy to believe that we can “fix” certain weaknesses of Western or high-performance breeds by introducing the genes of African livestock into them.

This does not make it less urgent to conserve pastoralist livestock, as food security for people in marginal areas remains a major concern. In their Biocultural Community Protocol, the Samburu have testified how replacement of the Red Massai sheep with Dorper has undermined their drought resistance.

African livestock breeds and their unique traits can only be conserved in living systems, using agroecosystem approaches as spelled out in one of the Strategic Priorities for Action of the Global Plan of Action for Animal Genetic Resources. Consequently we need enabling policies for livestock keepers, much more than additional research at the genome level — which would be unable to address complex traits such as walkability.