- Dave’s Garden does the apple forests of Almaty.
- Agave nectar sweetens the prospects of Otomi women in Mexico.
- Rhizowen investigates silverweed while taxonomists slug it out: Potentilla anserina or Argentina anserina?
- Just what the urban poultryperson needs: a hotel for chickens.
- National Gene Bank of Egypt website untouched.
- A diplomat visit’s Cameroon’s Cornice Agro Pastorale, and is impressed.
- Tackling climate change benefits health … and vice versa.
- Almost certainly more than you needed to know about Palm Oil palm.
Nibbles: Barley, Fellowship, Supplier, Malnutrition, choices, Rice and climate change
- “[A]n ancient barley grain”. Just the one. One only. From Neolithic England.
- Crawford Fund Fellowship “for an agricultural scientist from a selected group of developing countries whose work has shown significant potential”.
- New World Seeds & Tubers, a supplier thereof.
- Alternative remedies for late potato blight.
- Mild underweight a better indicator of childhood malnutrition than severe. Press release and paper.
- “Food or the environment? Mixed signals confuse farmers.” There has to be a choice?
- Indonesia sorts out its rice-adapted-to-climate-change problem.
Nibbles: IK, Fragaria, Citrus, Millet breeding, Vitis, Agricultural biodiversity, Satellite imagery, Subsistence
- Indigenous knowledge of agrobiodiversity makes the news in Indonesia.
- Reconstructing the strawberry.
- And reconstructing the history of cultivated citrus fruits.
- ICRISAT millet breeders get an a new toy.
- Plenty of diversity in the cultivated grape still. And it’s going to need it.
- Biodiversity (and agrobiodiversity?) needed for farm productivity. Well I never! But more mixed results available too. What’s a poor boy to think?
- SPOT 5 imagery can be used to identify crops. In Texas. But in Tanzania?
- Agricultural biodiversity and subsistence traditions, Part 2. In the Ozarks. But in Omo? (And here’s Part 1.)
Maize mystery solved
Joost van Heerwarden and co-workers ((van Heerwaarden J, Doebley J, Briggs WH, Glaubitz JC, Goodman MM, de Jesus Sanchez Gonzalez J, & Ross-Ibarra J (2010). Genetic signals of origin, spread, and introgression in a large sample of maize landraces. Proceedings of the National Academy of Sciences of the United States of America PMID: 21189301)) have solved a problem in our understanding of maize domestication. Previous work had shown that maize originated from Balsas teosinte, Zea mays subspecies parviglumis, a wild species that occurs in low and mid-elevation regions of south-west Mexico ((Matsuoka Y, Vigouroux Y, Goodman MM, Sanchez G J, Buckler E, & Doebley J (2002). A single domestication for maize shown by multilocus microsatellite genotyping. Proceedings of the National Academy of Sciences of the United States of America, 99 (9), 6080-4 PMID: 11983901)). This made the Rio Balsas area, where parviglumis occurs, the most likely area of maize domestication. This was corroborated by Piperno et al.‘s ((Piperno DR, Ranere AJ, Holst I, Iriarte J, & Dickau R (2009). Starch grain and phytolith evidence for early ninth millennium B.P. maize from the Central Balsas River Valley, Mexico. Proceedings of the National Academy of Sciences of the United States of America, 106 (13), 5019-24 PMID: 19307570)) discovery of 8,700 years old maize remains in that area; the oldest evidence of maize unearthed to date.
The problem was that the maize land races genetically most similar to parviglumis are not found there. They occur in the Mexican highlands. And that’s awkward, particularly because highland maize has a rather different set of ecological adaptations than lowland maize.
Van Heerwaarden et al. say this is a paradox caused by the role of another wild species: Zea mays subspecies mexicana. This species occurs in the highlands, and it is inter-fertile with cultivated maize. The tricky thing is that because the two wild species, parviglumis and mexicana, both referred to as teosinte, are closely related, more closely to each other than to their cultivated cousin, geneflow from mexicana makes the genes of highland maize look more like those of parviglumis!
This means that you cannot directly identify the most ancestral maize populations from genetic similarity with their putative ancestor. Instead, Van Heerwaarden et al. estimated ancestral gene frequencies from cultivated maize populations, without direct reference to the wild species. And, Bingo! Western lowland populations are indeed more ancestral than the highland populations. Maize did originate in the lowlands, and from there it spread to the highlands and to other parts of the Americas.
A brave new world for crop wild relatives
Thanks to Dr Brian Ford-Lloyd of the University of Birminghan in the UK for the following contribution.
A ground breaking publication in Nature Genetics points to the future for the genetic evaluation of crop wild relative germplasm. A group of Chinese scientists have used Illumina Next Generation Resequencing to produce whole genome sequences of 17 wild species of soybean. Only 17 wild species? But this is just the start for evaluating crop wild relatives on a completely different level than before — adding a different perspective to the analysis of genetic diversity, the identification of important adaptive differences between species, and locating novel allelic variation that can be used in crop improvement. One important result from the work is that they uncovered genetic variation in the wild species that has been clearly lost in cultivated material.