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2020 Stephen J O’Brien Award

2020 Stephen J O’Brien Award

2020 Stephen J O’Brien Award Outcome

The Stephen J. O'Brien Award for the best student paper published in AGA's Journal of Heredity honors Dr. O'Brien's many years of service as Chief Editor of the Journal.  This year, ten articles in Volume 110 that were first-authored by a student were considered, and the award presented to Marshall Wedger for his article, Discordant Patterns of Introgression Suggest Historical Gene Flow into Thai Weedy Rice from Domesticated and Wild Relatives (Marshall J Wedger, Tonapha Pusadee, Anupong Wongtamee, Kenneth M Olsen). JHered 2019. 110-5, pp 601-609.

The evaluation committee had the following comments on this top-ranked article:

"Nicely designed study of introgression between wild and domesticated rice strains, showing evidence for historic gene flow.  Large sample size, and although small numbers of loci, well-tempered results and conclusions.  Has important practical implications for human food security.”

Marshall will receive a $2,000 prize, a certificate, and up to $1,500 toward expenses to attend and present a talk at the 2020 AGA President’s Symposium.

The article is freely available to read and download.

Wedger et al. 2019 Study Summary and Importance
Weedy rice is a de-domesticated form of rice that infests rice fields and aggressively outcompetes cultivated crop varieties.  It is a worldwide agricultural problem, with almost every rice growing region around the world giving rise to its own independently-evolved strain of this devastating weed. Here in the United States, we are beginning to have a firm grasp on the basics of weedy rice evolution.  However, our rice agro-ecosystem is relatively simple compared to Asia, where thousands of different rice varieties are cultivated and where reproductively compatible wild rice populations can occur near cultivated and weedy rice populations. This study is the result of an important collaboration with a team of researchers in Thailand, where the wild rice ancestor is abundant, and the weed is a direct descendant of local crop varieties. Here we use three well-characterized domestication genes and 12 neutrally evolving SSRs to genotype 388 rice samples to make inferences about the history of weedy rice in the region, including its role as a bridge for gene flow in the crop-weed-wild agro-ecosystem. The results of this study are important as they shed light on the multi-generational evolutionary consequences of gene flow from crop to weed to wild plants and back.

Marshall Wedger Biography
My name is Marshall Wedger, and I am a graduate student in Dr. Kenneth Olsen’s lab at Washington University in St. Louis. I am originally from northern Minnesota, where I began my life as a researcher with Dr. Briana Gross at the University of Minnesota in Duluth studying the population genetics of local heritage apple varieties at a rediscovered test orchard. My current interests lie in agricultural weed evolution.  This has led me to a variety of research topics including seedling root phenotypes, parallel evolution of weediness, whole genome changes in response to changing agricultural practices, and even kin recognition.


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