Dr. Janaki R.R. Alavalapati, Dean
School of Forestry & Wildlife Sciences
3301 Forestry and Wildlife Building
602 Duncan Drive
Auburn, Alabama 36849-3418
Caterina Villari, Assistant Professor, Warnell School of Forestry and Natural Resources, University of Georgia, and Co-Director, Southern Pine Health Research Cooperative
“Rapid identification of disease resistant trees via advanced spectroscopy-based phenotyping”
Seminar is held at 11 a.m. in Conference Room 1101 in the SFWS Building, 602 Duncan Drive, Auburn, AL.
Abstract: With the rapid growth of international trade, we are facing an increase in the introduction of invasive pests into North American forests. The use of genetic resistance could provide a solution to protect our native forests, especially when other management options have proven neither feasible nor successful, which is the case for many past examples. However, unless we implement marker assisted selection, conventional breeding of forest trees takes decades, even in those instances in which advance breeding and propagation can be used. In this seminar, I will describe the use of chemical spectroscopy-based fingerprinting techniques, such as Raman or Fourier-transform infrared (FT-IR) spectroscopy, for the rapid selection of resistant trees. In particular, I will bring the example of a collaborative study which involved several European and North American institutions. The aim of the project was to test the feasibility and efficacy of FT-IR spectroscopy to rapidly phenotype European ash (Fraxinus excelsior) genotypes resistant or susceptible to ash dieback, a lethal disease caused by the invasive ascomycete Hymenoscyphus fraxineus. Analysed samples comprised both leaves and twigs collected in six European countries from trees that had been previously characterized in terms of resistance. Leaf and twig phenolic extracts were analysed with FT-IR, and resulting spectra were incorporated in a soft independent modelling of class analogy (SIMCA) model to predict the phenotype of the trees. While models built with leaves showed little power, probably due to the high chemical variability of leaf tissues, the ones built with twigs were very powerful, indicating that FT-IR can clearly discriminate between ash phenotypes displaying contrasting resistance levels to ash dieback. The SIMCA model was then validated using a separate set of completely blind samples, and showed a very high overall prediction accuracy. The implementation of spectroscopy-based techniques for resistance phenotyping has the potential to revolutionize the selection and breeding of resistant trees, not only in the European ash-ash dieback system, but potentially in many other pathosystems as well.
Biography: Caterina Villari is an Assistant Professor in Forest Pathology at the Warnell School of Forestry and Natural Resources, University of Georgia, and Co-Director of the Southern Pine Health Research Cooperative. She has a B.S. in Forest and Environmental Sciences and a M.S. in Plant Health Sciences and Technologies, both from the University of Florence (Italy). She received her Ph.D. in Crop Science, Plant Protection Curriculum from the University of Padua (Italy), and did her postdoctoral work at the Ohio State University, Department of Plant Pathology. Her main scientific interests are the interactions among trees, fungal pathogens and insect herbivores, and related chemical ecology aspects. She works with symbioses between bark beetles and fungi, plant defense mechanisms, microbial communities and early detection strategies, using an interdisciplinary approach that involves ecological, metabolomic, and molecular analyses.