Does root complexity affect the response of maize (Zea mays spp. mays) to abiotic stresses?

Blissett, Elizabeth

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https://hdl.handle.net/2142/49658 Copy

Description

Title

Does root complexity affect the response of maize (Zea mays spp. mays) to abiotic stresses?

Author(s)

Blissett, Elizabeth

Issue Date

2014-05-30T17:03:20Z

Director of Research (if dissertation) or Advisor (if thesis)

Bohn, Martin O.

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Maize
• Root
• Complexity
• Stress
• Tolerance

Abstract

As concerns of climate change grow and the world population increases the demands on agricultural production, developing stress tolerant cultivars is a key step towards feeding the world in 2050. The mechanisms of response that cause plants to tolerate abiotic stresses like drought, high temperature, or low nutrient availability are often not well understood; however, abiotic stresses are some of the most influential factors affecting maize yields. Two of the most relevant stresses faced by growers are drought stress and low nitrogen fertility. Furthermore, production in the U.S. Corn Belt will likely continue to be significantly affected by the more frequent occurrence of hot, dry growing seasons. In the cases of nutrient and water acquisition, it is obvious that the root system of the maize plant is essential. Given the importance of the root system in plant performance, it is intuitive that differences in root characteristics would impact the performance of maize under water and nutrient limited conditions. Despite its importance, maize root architecture and its involvement in plant performance is a relatively unexplored area; however, it is possible to accurately and quantitatively describe the root system of maize. A new and valuable tool in this effort is the use of fractal geometry and high-throughput phenotyping to assign a value to the complexity of the root system. Significant genetic variation exists for root system complexity in maize, making it a possible breeding target. Prior to the initiation of this study, fractal geometry was used to phenotype the root systems of maize hybrids selected for this study and to classify them as either high- or low-complexity root systems. The impact of varying root characteristics on agronomic performance and overall yield still needs to be investigated. In stressed environments, the root system is likely critical in maintaining function and thus protecting yield. In this study we investigated the relationship between root complexity and biomass partitioning when maize plants are subjected to the abiotic stresses of low nitrogen availability and drought stress. These represent two of the primary stresses growers face and it has been suggested that the adaptability of maize to low nitrogen stress confers drought tolerance. By growing trials in both field and greenhouse environments, a comprehensive set of information was collected allowing us to better describe the role of root system complexity in creating stress tolerant cultivars. We anticipate that the findings of this study will be critical in understanding the relationship between root complexity and key abiotic stresses and will guide breeding efforts to develop maize cultivars with improved stress tolerance.

Graduation Semester

2014-05

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http://hdl.handle.net/2142/49658

Copyright and License Information

Copyright 2014 Elizabeth Blissett

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