Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient Mexican maize varieties

30.06.2008
Sequencing of ancient corn landraces to ensure genetic diversity and resources
Maize was first domesticated in the highlands of Mexico about 10,000 years ago and is now one of the most important crop plants in the world.

It is a member of the grass family, which also hosts the world's other major crops including rice, wheat, barley, sorghum, and sugar cane. As early agriculturalists selected plants with desirable traits, they were also selecting genes important for transforming a wild grass into a food plant.

Since that time, Mexican farmers have created thousands of varieties suitable for cultivation in the numerous environments in the Mexican landscape—from dry, temperate highlands to moist, tropical lowlands. Because of its importance as food, the need to improve yield, and the challenges presented by changing climate, the maize genome of the B73 cultivar is being sequenced.

However, because maize has a complex genome and many varieties, the genome sequence from just one variety will not be adequate to represent the diversity of maize worldwide. Mexican scientists are also sequencing and analyzing the genomes of the ancient landraces to recapture the full genetic diversity of this complex and adaptable crop.

Dr. Vielle-Calzada and his colleagues, Octavio Martinez de la Vega, Julio Vega-Arrenguin, Gustavo Hernandez-Guzman, Enrique Ibarra-Laclette, Beatriz Jimenez-Moraila, Guilermo Corona-Armenta, Cesar Alvarez-Mejia, Araceli Fernandez-Cortes, Gustavo de la Riva, Alfredo Herrera-Estrella, and Luis Herrera-Estrella, are in the process of sequencing one of the ancient popcorn races, Palomero, and analyzing its molecular and functional diversity relative to other maize races.

Dr. Vielle-Calzada, of the National Laboratory of Genomics for Biodiversity, Cinvestav, Mexico, will be presenting this work at a symposium on Maize Biology at the annual meeting of the American Society of Plant Biologists in Mérida, Mexico (June 28, 11:30 AM).

Like other varieties of maize, the popcorn landraces are used throughout the world. Archeological evidence traces the earliest popcorn in the USA to New Mexico, suggesting an overland dispersal from the highlands of central Mexico into the northern plains of Mexico and then into the southwestern USA. Recent studies also support the hypothesis that popcorns are some of the oldest races of maize and group closely with teosinte in phylogenetic analyses.

Palomero is an ancient popcorn landrace of the Central and Northern Highlands Group. Vielle-Calzada and his colleagues estimated that its genome is about 22% smaller than that of B73. Their structural and functional analysis of this genome reveals a large number of unreported sequences, suggesting that the ancient landraces contain a large pool of unexplored genetic diversity that could be useful in new crop generation as well as the study of the evolution and domestication of maize and other cereals. Other studies in Mexico and elsewhere have shown that Mexican maize varieties are extraordinarily diverse.

Maize is a good model plant for studying the development of cereal crops because of its complex genome, numerous developmental mutants, and thousands of varieties. It is thought that as many as 1200 genes were selected in the process of transforming maize into a versatile food plant, and the process continues today. In regions throughout Mexico, farmers still cultivate local or criollo maize varieties in traditional ways as well as generating new varieties. They are thus contributing to conservation of the genetic diversity of maize and preserving traits that could be useful in yet unforeseen circumstances.

Many of the ancient varieties like Palomero were adaptations to different environmental conditions such as different soils, temperature, altitude, and drought. Preservation of these varieties and knowledge of their genetic and adaptive histories are of paramount importance as farmers around the world cope with changes in temperature and water availability and struggle to maintain a food supply for growing populations. These sequencing efforts are providing the data for genomic and mutant analyses that are needed for the genetic engineering of crops to improve yield as well as resistance to pests and tolerance for difficult growing conditions. The knowledge gained from these efforts can also be applied in crop and yield improvement efforts for other cereals.

Dr. Jean-Philippe Vielle-Calzada | EurekAlert!
Further information:
http://www.ira.cinvestav.mx

More articles from Agricultural and Forestry Science:

nachricht Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge

nachricht Unusual soybean coloration sheds a light on gene silencing
20.06.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>