Date of Award


Degree Name

MS in Agriculture - Soil Science


Natural Resources Management


College of Agriculture, Food, and Environmental Sciences


Cristina Lazcano

Advisor Department

Natural Resources Management

Advisor College

College of Agriculture, Food, and Environmental Sciences


Microbial-root associations are important to help plants cope with abiotic and biotic stressors. Managing these interactions offers an opportunity for improving the efficiency and sustainability of agricultural production. By characterizing the bacterial and archaeal community (via 16S rRNA sequencing) associated with the bulk and rhizosphere soil of sixteen strawberry cultivars in two controlled field studies, we explored the relationships between the soil microbiome and plant resistance to two soilborne fungal pathogens of strawberry (Verticillium dahliae and Macrophomina phaseolina). Overall, the plants had a distinctive rhizosphere microbiome relative to the bulk soil, with higher abundances of known beneficial bacteria such as Pseudomonads and Rhizobium. Plant genotype, biomass, leaf nutrient content and mortality were influenced differently by the rhizosphere microbiome in each of the two trials. In the V. dahliae trial, the rhizosphere microbiome was associated with plant biomass and leaf nutrient content and only indirectly to the disease resistance. In the M. phaseolina trial, the rhizosphere microbiome was associated to plant biomass, but not nutrient content; furthermore, resistant cultivars had larger abundances of Pseudomonas and Arthrobacter in their rhizosphere relative to susceptible cultivars. The mechanisms involved in these beneficial plant-microbial interactions and their plasticity in different environments should be studied further for the design of low-input disease management strategies.

Included in

Soil Science Commons