Current Lab Members

Faculty and Staff

Mark Williams, Lab Director


I am an Assistant Professor in the Department of Horticulture. Before coming to Virginia Tech, I studied and worked at Oregon State University, Kansas State University, University of Georgia, and Mississippi State University.

In addition to my research, I teach the Ecology of Plant-Microbial Interactions (HORT 5984). Plant-microbial-soil feedbacks are a large focus of study in this class. Half the course is lecture and the other half is based on student presentation of recent journal articles.

Amanda Karstetter, Research Assistant



Andi Lantin, Research Assistant



Kerri Mills, Research Technician



Graduate Students

Jude Moon, PhD Candidate


I am from South Korea where I studied Microbiology and received my B.S. During my undergraduate, I visited the U.S. for first time as an exchange student. During that time, I decided that I wanted to pursue graduate school. My studies are focusing on root-zone and soil microbial ecology, with an emphasis on how plants and microbial proteins contribute to soil processes and soil organic matter formation.

Rosana Pineda, PhD Candidate


I am from Colombia where I studied Agronomy and received my M.S. in Biotechnology. In 2012, I started my doctoral studies in the Department of Horticulture, so now I am a Hokie! My research will be assessing the relationship between fungal community development in ecosystems and how they co-vary with plants and soils.

Published Papers

Variabilidad genética de aislamientos de Phytophthora infestans procedentes del suroeste de Colombia

Current situation of wild Solanum spp. L. sect. Petota (Solanum, Solanaceae) in some Colombian regions

Characterización Citogenética de Cinco Genotipos de Papa Criolla, Solanum phureja (Juz. et Buk.)

Richard Rodrigues, PhD Student


I received my undergraduate degree in Biotechnology from Kolhapur Institute of Technology, India. I completed my Masters in Bioinformatics at Rochester Institute of Technology, NY in 2011. I am currently pursuing my Ph.D. in Genetics, Bioinformatics, and Computational Biology. For my doctoral research I am investigating the structure and function of nitrogen fixing bacterial communities in the root-zone of Switchgrass. Apart from research and living by our motto (Ut Prosim), I serve as the Treasurer of the Graduate Student Assembly and a member on various committees to benefit the student community at Virginia Tech.

Jayani Wewalwela, PhD Student


I am from Sri Lanka and I was a graduate student in Dr. Mark Williams lab in Department of Plant and Soil Sciences, Mississippi State University from 2010 to 2011. After Dr. Willimas moved to Virginia Tech, I have joined Dr. Janet Donaldson lab in Department of Biological Sciences, Mississippi State University and I continue my research work in collaboration with Dr. Williams. My research project is on identification of associative nitrogen fixing bacteria from biofuel feedstock grasses and quantification of their potential for nitrogen fixation.

Hua Xiao, PhD Student


I am from China, a Ph.D. student in the Department of Horticulture at Virginia Tech and an ICTAS Doctoral Scholar. My advisors are Drs. Mark Williams and Richard Veilleux. I received my Bachelors degree in Biological Science and Masters Degree in Zoology. My research is now focusing on the influence of iron candidate genes and interaction between plant and rhizospheric microbial community on iron accumulation in native Andean potatoes. I am trying to improve the iron nutritional quality in the native potato cultivars by using biotechnology and soil microbial community management.

Undergraduate Students

Natalie Chen

Haley Feazel

Saman Khan

Anna Lacsamana

Spencer Sauter

Kelsey Weber

Former Lab Members

Wade Anderson

David Doan

Lia Doumar

Yoonji Ha

Hasheem Halim

Nolan Hodge

Ping Hu

Madhavi Kakumanu

Audrey Longfellow

Maia Mula-Michel

Nick Preskitt

Ashley Rhodes

Shankar Shanmugam

Amy Vu

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