Pseudomonas spp. Isolated from the Soybean Nodule Interior Promote Soybean Growth upon Field Amendment

Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria (PGPR). This study observes the soybean growth promoting potential of Pseudomonas spp. in a field setting. Additionally, this study observed differences in soybean growth promotion based on amending the plant with isolated strains or a mixed culture of the species' strains. Two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were either amended with isolated strains of the novel Pseudomonas spp. (referred to as PAMW1 and BUMW2 in this study), a mix of the two strains, or an uninoculated control. The study recorded measurements to observe growth, yield, and nitrogen fixation differences. The study uses two-way factorial ANOVAs and non-parametric, multivariate analyses to determine differences in growth promotion among samples. Soybean amended with PAMW1 has greater shoot mass, biomass, and height than other treatments. Through nonmetric multidimensional scaling (NMS), samples amended with a mixed culture or PAMW1 may be different regarding growth promotion relative to the non-amended samples. Univariate results support the hypothesis that the novel Pseudomonas spp. benefit soybean in a field setting. However, it is inconclusive whether a mixed culture amendment of multiple strains alters the overall growth promotion of soybean compared to samples amended with isolated strains.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2022

Author dc:creator

• Doyle, Connor Patrick

Chair dc:contributor.committeechair

• Williams, Mark A.

Committee members dc:contributor.committeemember

• Vinatzer, Boris A.
• Fike, John H.

• Pseudomonas spp.
• Plant Growth-Promoting Rhizobacteria (PGPR)
• Soybean
• Growth
• Bradyrhizobium spp.
• Nodule Sterilization
• Bacterial Extraction
• Nitrogen Fixation
• Phosphorus Solubilization
• Indole-3-Acetic Acid (IAA)
• Siderophore
• Analysis of Vari

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:35341

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/111684