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“Nitrogen fixation in maize landraces from Oaxaca, Mexico: from Indigenous knowledge to the Wisconsin Idea”
February 9, 2021 @ 12:00 pm - 1:00 pm
About the presentation: Plants are associated with a complex microbiome that contributes to growth, nutrient acquisition, and defenses. Nitrogen-fixing microbial associations are well-characterized in legumes but are mostly absent from cereal crops, including maize.
We studied an Indigenous maize landrace grown without using nitrogen fertilizers in the nitrogen depleted soils of Totontepec Villa de Morelos in Oaxaca, Mexico. This landrace is characterized by the extensive development of aerial roots that secrete a sugar-rich mucilage (gel) after rain. These landraces are also very tall and grow over 9-10 months. The mucilage is enriched in nitrogen-fixing bacteria and supports an intense nitrogen fixation activity. Field and greenhouse experiments in Totontepec Villa de Morelos and Wisconsin, using two different assessments (15N natural abundance and 15N-dilution assessments), over five years, demonstrated that plants were acquiring half of their nitrogen from the air.
In collaboration with the Centro Internacional de Mejoramiento de Maiz y Trigo –CIMMYT-, we identified several maize landraces from other locations throughout Oaxaca that present the same characteristics. We also found the trait in some teosinte species, the progenitor of domesticated maize. We are currently studying the plant and bacterial genes controlling nitrogen fixation on aerial roots, evaluating the trait’s environmental limits, its impact on yield, and its evolution. To make this nitrogen fixation available to a wide range of maize growers in developed and developing countries, we have started introducing the trait into maize varieties with a more standard size and growth features. We are also exploring avenues for traditional growers to breed for nitrogen-fixation locally using this knowledge and tools that we are developing.
About the presenter: Dr. Jean-Michel Ané is a Professor in the Bacteriology and Agronomy departments at the University of Wisconsin – Madison. His primary research interest is understanding the molecular mechanisms allowing efficient symbiotic associations between plants and microbes and applying this knowledge to maximize the benefits of such associations in agriculture.
His specific goals are to (1) understand the genetic and molecular mechanisms allowing the establishment of mycorrhizal and nitrogen-fixing associations across land plants, (2) study the evolution of these mechanisms to identify critical innovations that enabled the development of these associations and (3) use this knowledge to engineer more efficient associations between crops and microbes to improve the sustainability of our agriculture for food, feed, and biofuel production.
Please register HERE. Once you are registered, you will have access to the Zoom meeting shortly before the presentation begins.