People

Jane Stewart

Principal Investigator

Associate Professor
Laboratory Supervisor
jane.stewart@colostate.edu

Research Staff

Dr. Jorge Ibarra Caballero

Research Associate III / Lab Manager
jorge.ibarra_caballero@colostate.edu
Jorge is a research associate at Colorado State University. He received his PhD degree in Plant Pathology at Colorado State University with research focus on transcriptomics and proteomics of Pythium iwayamai which causes snow blight of turfgrass. He also worked on the population genetics of Geosmithia morbida, a pathogen of the thousand canker disease of walnut. He is currently involved in many research projects in the Stewart Lab which deals on genomics and transcriptomics of various plant pathogens such as Rafaelea lauricola causing laurel wilt disease, Phellinus noxius causing brown root rot on tropical trees, Cytospora leucostoma causing peach canker, and Armillaria species causing root rot. He also investigates the microbial communities in potato fields in the presence of pathogens using metagenomics. Further, he collaborates with USDA Forest Service on various projects such as the development of protocol for the detection of Cronartium ribicola causing white pine blister rust through loop-mediated isothermal amplification.

Post Doc

Shankar Gaire

Post Doc

Shankar is a postdoctoral fellow at Colorado State University with a rich background in plant pathology and fungal genomics. He earned his Ph.D. in Plant Pathology from Texas A&M University in 2021, where his research focused on rice seedling diseases, the population genomics of Rhizoctonia solani, and plant-host resistance. Following his doctoral studies, Shankar joined Louisiana State University as a postdoctoral researcher. There, he delved into the rice–Cercospora pathosystem, specifically working on the positional cloning and characterization of the narrow brown leaf spot (NBLS) resistance gene CRSP2.1. His research utilized fine mapping, comparative genomics, and transcriptomics to map and genetically characterize CRSP2.1, identifying key candidate genes associated with disease resistance. Before his current position at Colorado State University, Shankar worked as a Senior Scientist-I (Bioassay) at Eurofins BioPharma Product Testing at Columbia, Missouri. His diverse research interests include fungal population genomics, phylogenomics, pathogen biology, the coevolution of plant major resistance (R) genes and pathogen avirulence (AVR) genes, and the genetics underlying plant host resistance. In 2024, Shankar joined the Stewart Lab to investigate the biology and the mechanisms of hybridization between two rust pathogens: the invasive Cronartium ribicola and the native Cronartium comandrae. By examining hybrid genetics and introgressive hybridization, Shankar aims to understand the role of hybridization in the evolution and emergence of new fungal pathogens.

Carolyn Cornell

Post Doc

Carolyn Cornell is a Postdoctoral Fellow investigating the factors driving the emergence of brown spot needle blight in the southeastern US caused by the fungal pathogen Lecanosticta acicula. Before coming to CSU, she completed a postdoctoral fellowship at Rice University studying microbial nitrogen cycling in agricultural soils and assessed the ability of carbon amendments to mitigate microbial nitrous oxide emissions. Carolyn received her PhD in Microbiology from the University of Oklahoma in 2022, where she studied the spatial and temporal responses of soil bacterial and viral communities under increasing land management intensity in a US Southern Plains agroecosystem. Her research focus is microbial ecology, including the interactions between microbial communities and the effects of environmental changes on microbial community dynamics and ecosystem services in agricultural systems.

Graduate Students

Ashley Miller

PhD Student
ashley.e.miller@colostate.edu

Ashley Miller is a PhD student studying physiological and genomic responses of high-elevation pine trees to the fungal pathogen that causes white pine blister rust, and how the pathosystem may be affected by climate change. Ashley obtained a B.Sc in Botany at Oregon State University, an M.Sc with a focus in tree ecophysiology in boreal environments from the University of Freiburg, Germany, and a Master of Forestry from the University of Alberta, Canada. 

Almendra Astete Farfan

PhD Student
almendra@colostate.edu

Almendra received her bachelor’s degree in Biology from the Universidad Nacional San Antonio Abad del Cusco in Peru by studying the population structure of potato late blight pathogen Phytophthora infestans in collaboration with the International Center of Potato. Before arriving at CSU, Almendra was trained in molecular biology techniques to study host-pathogen interactions between tomato and Phytophthora capsici at the James Hutton Institute in Scotland. She also collaborated on crop breeding projects to confer resistance against P. infestans and Papaya ringspot virus at the Peruvian Institute of Agrarian Innovation, and microbiological screening of blueberry endophytic-fungi with biocontrol activity against Botrytis cinerea at the Peruvian University of Cañete. Almendra completed her M.Sc. in Plant Pathology at CSU by investigating the weed biocontrol potential of the rust fungus Puccinia punctiformis against the creeping thistle, Cirsium arvense. Her current research focuses on Fusarium spp. and their pathogenicity against conifers.

Ada Fitz Axen

PhD Student
ada.fitz_axen@colostate.edu

Ada Fitz Axen is a PhD student working with population genetics of the invasive fungal pathogen Austropuccinia psidii. She recently obtained her M.S. in Plant Pathology from Colorado State University, where she researched how the soil microbial communities associated with Armillaria root disease respond to fire disturbance in western conifer forests. Ada is from Minneapolis, Minnesota, and enjoys hiking, paddle boarding, cross country skiing, and baking in her free time.

Michael McKee

MSc Student

Michael McKee is a M.S. student studying the drivers of ponderosa pine dieback and mortality in western forests. He is working with the Forest Service Evaluation Monitoring program to characterize ponderosa decline. He is also working on multiple virulence assays for needle and canker pathogens and a LAMP assay for Pine Wilt Nematode.

Michael is from Indiana and obtained a B.S. in Botany and Plant Pathology from Purdue University. During his time at Purdue, he worked as an undergraduate researcher for the USDA soybean breeding program. After graduation, he worked for AgReliant Genetics as a Research Associate in Plant Pathology studying diseases of corn. 

In his free time, Michael enjoys hiking, fishing, exercising, and watching sports.

Grace E. Ganter

MSc Student

Grace has been with the Stewart lab since 2021 as an undergraduate field and laboratory technician. After obtaining her B.S. in Agricultural Biology from Colorado State University in 2023, she started her master’s degree. Grace is currently working on studying the microbial communities associated with Fusarium pathogens in conifer nurseries, and how these communities change when trees are planted in reforestation sites. Grace is originally from Albuquerque, New Mexico, and outside of work enjoys skiing, hiking, and cooking.

Noah Lindeman

MS Student
noah.lindeman@colostate.edu

Noah Lindeman is a graduate in the stewart lab. He is studying the root pathogen Onnia tomentosa. Noah is working on developing a LAMP assay for this pathogen. This LAMP assay is a diagnostic tool that can be used in the field for identifying Onnia tomentosa. He is also investigating if Onnia tomentosa is not one species but a species complex. In his free time, Noah enjoys reading, hiking with friends and foraging. He is originally from the Californian coast, and is looking forward to learning the edible plants and fungi of Colorado.

Pavan Silva

MSc Student

Pavan Silva is an M.S. student at Colorado State University. He earned his bachelor’s degree in Microbiology with minors in Zoology and Chemistry from the University of Sri Jayewardenepura, Sri Lanka. Pavan’s passion for plant pathology and mycology developed during his undergraduate studies. His undergraduate research project was focused on identifying fungi associated with mango anthracnose and leaf spot diseases in Sri Lanka, where mangoes are a vital source of nutrition. In the Stewart Lab, he studies the population biology and management of Cytospora canker in peach trees. This disease, caused by Cytospora plurivora, significantly impacts Colorado’s peach production, and understanding the pathogen is essential for effective management. He is originally from Colombo, Sri Lanka, and in his free time, he enjoys watching documentaries, reading and traveling.

Undergraduate Students

Olivia Watson

Undergraduate Researcher

Olivia is studying Agricultural Biology with a concentration in Plant Pathology at CSU. She has the most experience working with the root rot fungus Onnia tomentosa, but has contributed to many other pathogenic fungi projects, enjoying the experiences from each one. Outside of research, Olivia enjoys art, trail riding with her horse, and movies.

Mekala Stiffler

Undergraduate Researcher

Mekala is an undergraduate at CSU studying Environmental Engineering. She first joined the Stewart Lab through the BROADN REU program. Mekala is currently involved with several projects researching the effects and aerial spread of White Pine Blister Rust.

Justina Rice

Undergraduate Researcher

Justina is a senior at Colorado State, pursuing a degree in Agricultural Biology with a concentration in Plant Pathology and a minor in Plant Health. Her academic interests include the study of fungal pathogens in agricultural systems, plant-pathogen interactions, and the impacts of soil systems on plant health. Outside of her academic and research interests, Justina enjoys hiking, crocheting, and reading.