Investigating the Abilities of Potentially Beneficial Bacteria for Increasing Nitrogen-Use Efficiency in Maize

Authors

Lexie R. Foster, University of Nebraska-LincolnFollow

First Advisor

Daniel P. Schachtman

Committee Members

Karrie Weber, Jinliang Yang

Date of this Version

7-2024

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Biological Sciences

Under the supervision of Professor Daniel P. Schachtman

Lincoln, Nebraska, July 2024

Comments

Copyright @ 2024, Lexie R. Foster. Used by permission

Abstract

Global agriculture relies heavily on the use of synthetic nitrogen fertilizer to meet the current global food demand. Unfortunately, the average nitrogen-use efficiency (NUE) of maize (Zea mays) is approximately 50 percent. Improving the NUE of maize is essential for meeting the growing global food demand while also decreasing the negative environmental impacts caused by losses of nitrogen fertilizer due to runoff and volatilization. Harnessing the symbiotic relationship between plants and the soil microbiome may be one method for increasing the NUE in crops such as maize. In the present study, a set of potentially beneficial bacterial species were investigated for their ability to improve NUE-related traits in maize grown under nitrogen deficient conditions. Two bacterial isolates, Arthrobacter sp. and Pseudomonas kribbensis exhibited plant-growth promoting capabilities in the Mo17 maize genotype grown under nitrogen-deficient conditions. The time points at which the two bacterial isolates offered a significant effect differed, as the Arthrobacter sp. offered a significant growth effect at 14 days of growth, while Pseudomonas kribbensis offered a significant growth effect starting at 21 days of growth. While Arthrobacter sp. and Pseudomonas kribbensis offered plant-growth promotion in the Mo17 maize genotype under low nitrogen, other genotypes were not positively influenced, suggesting a specific plant genotype and bacterial species relationship. Exploring the plant-growth promoting effects of bacterial isolates sampled from nitrogen-deficient maize genotypes is one avenue in increasing the NUE of crops.

Advisor: Daniel P. Schachtman