Actinobacterial Diversity and Its Role in Compost and Soil Suppression of Rhizoctonia Solani
Conference Year
January 2019
Abstract
Rhizoctonia solani is a global fungal plant pathogen that causes a variety of plant diseases and is detrimental to many commercial crops. R. solani can be suppressed by competitive or antagonistic microbes indigenous to some composts and soils. Anaerobic Soil Disinfestation (ASD) and application of vermicompost are two pesticide-free techniques used to control persistent soilborne plant pathogens. This is the first study to evaluate ASD in Vermont. We compared suppressiveness achieved by ASD to a positive control (vermicompost) and untreated soil to test the hypothesis that abundance and diversity of actinobacteria increase after ASD. These organisms thrive in conditions that ASD produces, for example, extreme heat and copious labile carbon. A general plate competition assay was used to measure the amount of suppression on R. solani from the compost and soils. Suppression by specific groups was determined on starch casein agar. From these plates, cultures of suppressive actinobacteria were isolated and their functional diversity of carbon utilization was characterized by EcologTM plates. Among all compost and soil samples, the soil microbiomes were essential to suppressing R. solani, however the level of suppression was greatest from the ASD soil (pp < 0.5) and slightly more diverse suppressive actinobacteria, suggesting a promising outlook into using ASD soil to reduce R. solani plant infections.
Primary Faculty Mentor Name
Deborah Neher
Secondary Mentor Name
Thomas Weicht
Status
Undergraduate
Student College
College of Agriculture and Life Sciences
Program/Major
Biological Sciences, Integrated
Primary Research Category
Biological Sciences
Actinobacterial Diversity and Its Role in Compost and Soil Suppression of Rhizoctonia Solani
Rhizoctonia solani is a global fungal plant pathogen that causes a variety of plant diseases and is detrimental to many commercial crops. R. solani can be suppressed by competitive or antagonistic microbes indigenous to some composts and soils. Anaerobic Soil Disinfestation (ASD) and application of vermicompost are two pesticide-free techniques used to control persistent soilborne plant pathogens. This is the first study to evaluate ASD in Vermont. We compared suppressiveness achieved by ASD to a positive control (vermicompost) and untreated soil to test the hypothesis that abundance and diversity of actinobacteria increase after ASD. These organisms thrive in conditions that ASD produces, for example, extreme heat and copious labile carbon. A general plate competition assay was used to measure the amount of suppression on R. solani from the compost and soils. Suppression by specific groups was determined on starch casein agar. From these plates, cultures of suppressive actinobacteria were isolated and their functional diversity of carbon utilization was characterized by EcologTM plates. Among all compost and soil samples, the soil microbiomes were essential to suppressing R. solani, however the level of suppression was greatest from the ASD soil (pp < 0.5) and slightly more diverse suppressive actinobacteria, suggesting a promising outlook into using ASD soil to reduce R. solani plant infections.