UC Davis Professor Emerita Valerie Moroz Williamson of the Department of Plant Pathology is the recipient of the international Society of Nematologists' highest honor: Honorary Member. Photo courtesy of UC Davis

DAVIS, CA (MPG) - UC Davis Professor Emerita Valerie Moroz Williamson of the Department of Plant Pathology is the recipient of the Society of Nematologists’ highest honor: Honorary Member.

Williamson, a fellow of the Society of Nematology (SON) and the American Association for the Advancement of Science (AAAS), received the plaque, inscribed with “For Outstanding Contributions to Nematology,” at its recent meeting in Baltimore. 

This makes the second year since 2024 that a UC Davis nematologist has received the distinguished honor. Then, UC Davis Distinguished Professor Emeritus Howard Ferris, internationally recognized for his “exceptional, wide-ranging and unparalleled contributions to nematology” over a 64-year career, won the award.

UC Davis Professor Shahid Siddique and Cynthia Gleason, associate professor, Washington State University, nominated her for Honorary Member.

Williamson received her bachelor's degree in biology from Northeastern University in Boston and worked three years at the Institute of Marine Science at the University of Alaska, Fairbanks, before seeking her doctorate. She obtained her PhD in biochemistry in 1978 from UC Davis, where she focused on RNA polymerase in Bacillus subtilis. She joined the UC Davis faculty in 1987 as an assistant professor, advancing to professor in 1997.

Siddique and Gleason noted that "Valerie has openly shared that her early years as a female STEM faculty member in the 1980s presented unique challenges. As one of the few women in her field, she faced several challenges. Yet her perseverance and scientific excellence were recognized in 2009, when she was named a fellow of the American Association for the Advancement of Science (AAAS). Over her 26 years at UC Davis, Valerie established herself as a leading authority in molecular nematology, mentoring students, publishing influential research, and elevating the profile of the field.” She retired in 2013, “leaving behind a legacy of innovation, leadership, and unwavering dedication.”

They wrote:

“A hallmark of her career has been her groundbreaking research on the Mi-1.2 gene, a nematode resistance gene in tomato. Among her publications, 27 are dedicated to the cloning and characterization of this gene, a feat that represented a watershed moment in plant-nematode interactions. Her landmark paper in The Plant Cell, ‘The Root Knot Nematode Resistance Gene Mi from Tomato Is a Member of the Leucine Zipper, Nucleotide Binding, Leucine-Rich Repeat Family of Plant Genes,’ has been cited over 1,000 times, underscoring its profound impact on the field. Cloning Mi-1.2 in the mid-1990s, when molecular biology was still in its infancy, was an extraordinary scientific breakthrough and a testament to Valerie’s vision and determination. The significance of her work was further reinforced by subsequent studies, including her influential paper in PNAS, ‘The Nematode Resistance Gene Mi of Tomato Confers Resistance Against the Potato Aphid,’ which has been cited over 900 times.”

“A similarly significant component of Valerie’s achievements is her pioneering work on understanding the genetics of root-knot nematodes. She was instrumental in establishing Meloidogyne hapla as a model root-knot nematode, highlighted by her seminal publication in Genetics, ‘Meiotic Parthenogenesis in a Root-Knot Nematode Results in Rapid Genomic Homozygosity.’ In this study, her lab developed a strategy for conducting genetic crosses between different M. hapla strains and generated novel markers to track segregation patterns. Building on this breakthrough, they published another landmark paper in G3, ‘A Sequence-Anchored Linkage Map of the Plant–Parasitic Nematode Meloidogyne hapla Reveals Exceptionally High Genome-Wide Recombination,’ in which they produced 183 F2 lines from a cross of two highly inbred strains and constructed a genetic linkage map that has been crucial for empowering M. hapla as a tractable model.”

“Even in retirement, Valerie has remained a prolific and innovative force, furthering her research into nematode attraction. Her transformative contributions have not only elevated the study of nematodes within plant pathology but have also left an enduring legacy of scientific excellence.”

Learn more at entnem.ucdavis.edu/news/professor-emerita-valerie-williamson-receives-sons-highest-honor