Venkateshwaran is an associate professor of crop physiology and molecular biology and the Soil and Crop Science Program coordinator at UW–Platteville. His research interests include plant-microbe symbioses, plant defense signaling, plant disease management, rhizosphere microbiome and sustainable agricultural practices. Venkateshwaran earned his PhD in plant pathology from UW–Madison.
Root rot of Alfalfa caused by Aphanomyces euteiches, an Oomycete pathogen, poses significant threat to alfalfa production in Wisconsin and many parts of the world. The pathogen infects both young seedlings as well as mature plants in well-established alfalfa fields. The fungicides that control other Oomycete pathogens, have proven to be ineffective in controlling this pathogen. Hence, host plant resistance is the only reliable strategy for the management of this pathogen. However, with the prevalence of multiple races of A. euteiches, current resistance mechanisms may not be effective soon.
We are using soil drenching of plant essential oil to reduce the pathogen population (inoculum density) in the soil as well as to reduce the disease incidence and severity. In the ongoing project, we assess the disease incidence and disease severity using Trypan blue-based staining of infected roots. However, the Trypan blue or fluorescent dye does not distinguish the A. euteiches from other root colonizers (both pathogens and symbionts). We plan to use quantitative, Real-Time Polymerase Chain Reaction (RT-PCR) based detection and quantification of A. euteiches in the soil as well in the infected roots.
The research team will use a homogenizer (Retsch Mixer Mill MM 400) to perform DNA isolation from soil and infected plant materials, a BOD incubator to set up growth inhibition assays, and supplies to perform soil and plant/fungal DNA isolation, and TaqMan-based RT-PCR assays.