Genetic diversity

May 25, 2011May 25, 2011

Maize hits the heights

The llama dung story got me thinking about high-altitude maize. Maize is a tropical plant and it would have taken quite a bit of effort to get it adapted to high elevations. This is what Genesys knows about maize around the world:

And this is (in red) where maize collected above 3,500 masl has been collected:

Those Andean agriculturalists obviously did a pretty good job of breeding maize to fit the new environment, and in fact still are.

LATER: As Jacob helpfully points out in a comment on this post, a 2002 paper confirmed, using microsatellites, that Andean maize is genetically quite distinct.

May 23, 2011May 23, 2011

Brainfood: Introgression, Sorghum and drought, Rice and drought, Carrot evaluation, Wheat breeding, Legume conservation, Wild Tibet soybean, Gezira, Biochar, CA, Grass ecotypes and climate, Organic ag and nutrients

Alien introgressions represent a rich source of genes for crop improvement. Polyploids such as wheat do it best.
Characterization of sorghum genotypes for traits related to drought tolerance. There is diversity within the “association panel” of diverse germplasm used. What I want to know is how that is different from a core or mini-core collection.
Rice near-isogenic-lines (NILs) contrasting for grain yield under lowland drought stress. Small genetic differences can lead to big differences in yield under drought stress. What I want to know is whether doing this on NILs is better value for money than doing it on association panels of germplasm (see above), whatever they may be.
Towards better tasting and more nutritious carrots: Carotenoid and sugar content variation in carrot genetic resources. European accessions sweeter and more orange than Asian.
Changes in duration of developmental phases of durum wheat caused by breeding in Spain and Italy during the 20th century and its impact on yield. Fascinating unpicking of just where the genetic changes have their impact.
Legume genetic resources: management, diversity assessment, and utilization in crop improvement. A lot of characterization, not enough evaluation. Core collections useful, but not useful enough. Crop wild relatives being used, but not enough. Good plug for the importance of geo-referencing.
Genetic diversity and geographical peculiarity of Tibetan wild soybean (Glycine soja). Low and high, respectively.
Analysis of agricultural production instability in the Gezira Scheme. Went up for wheat, cotton and sorghum, down for groundnuts, on liberalization.
Biochar effects on soil biota – A review. It’s complicated but, on the whole, not unpositive.
A research agenda to explore the role of conservation agriculture in African smallholder farming systems. Basically, it is likely to work least well in marginal conditions. Which is kinda surprising, and not, at the same time.
Ecotypes of European grass species respond differently to warming and extreme drought. Yeah, but, alas, not in the way one might have wished.
Comparison of nutritional quality of the crops grown in an organic and conventional fertilized soil. Maybe lower nitrate and N, higher P in organic crops. But really too much variation to be sure.

May 19, 2011

Nibbles: Canids, Pea, Cacao, Scallops

Dogs are different from wolves, different types of wolves are different from each other.
Vavilov-Frankel Fellow on the move.
Nacional cacao bean rediscovered in northern Peru.
Manx Queenies deemed to be sustainable. And wipe that smile off your face.

May 16, 2011May 13, 2011

Brainfood: Millet biscuits, Wheat micronutrients, Diversification and C footprint, Agroforestry, Epazote, Grape history, Belgian farmers, Millet phenology, Species migration, Barley domestication, Sheep genetics

Quality characteristics of biscuits prepared from finger millet seed coat based composite flour. They’re nutritious. Crocodile Dundee on the tastiness of the iguana may, however, apply.
Minerals and trace elements in a collection of wheat landraces from the Canary Islands. There are differences, but environment and agronomic practices could affect them.
Lowering carbon footprint of durum wheat by diversifying cropping systems. Yes, by 7-34%, depending on how the diversification was done.
Effect of shading by baobab (Adansonia digitata) and néré (Parkia biglobosa) on yields of millet (Pennisetum glaucum) and taro (Colocasia esculenta) in parkland systems in Burkina Faso, West Africa. Taro is a shade lover; grow it under néré, and vice versa.
Ethnobotanical, morphological, phytochemical and molecular evidence for the incipient domestication of Epazote (Chenopodium ambrosioides L.: Chenopodiaceae) in a semi-arid region of Mexico. Good to know; I love epazote.
Grape varieties (Vitis vinifera L.) from the Balearic Islands: genetic characterization and relationship with Iberian Peninsula and Mediterranean Basin. See the grand sweep of European history unfold.
Microsatellite characterization of grapevine (Vitis vinifera L.) genetic diversity in Asturias (Northern Spain). No evidence of communication with the previous group.
Plant economy of the first farmers of central Belgium (Linearbandkeramik, 5200–5000 b.c.). They were dope fiends.
Selection for earlier flowering crop associated with climatic variations in the Sahel. Compared to 1976 millet samples, samples collected in 2003 had shorter lifecycle (due to an early flowering allele at the PHYC locus increasing in frequency), and a reduction in plant and spike size. So you don’t need new varieties, the old ones will adapt to climate change. Oh, and BTW, there’s been no genetic erosion.
Do species’ traits predict recent shifts at expanding range edges? No.
The domestication syndrome genes responsible for the major changes in plant form in the Triticeae crops. Failure to disarticulate and 6-rows in barley, in detail. Part of a Special Issue on Barley.
The genetics of colour in fat-tailed sheep: a review. I didn’t know karakul had fat tails.

May 12, 2011May 12, 2011

Nibbles: Fruit-tree fundraiser, Bangladesh seed crisis, Mead, Early farmers, Fruit genebank

Bioversity promotes a fund-raiser for forgotten fruit trees.
Seed crisis in Bangladesh. It’s complicated. Really complicated.
Belatedly, mirthful report on mead.
“…during the advent of agriculture … early farmers may have at first come together in communal activities, prior to congregating in villages.”
USDA’s fruit genebank at Corvallis in the news.