Overview

I am interested in how phenotypes are determined from genetic and environmental factors. I have conducted or am conducting research in epigenetics, abiotic stress tolerance, nutritional quality and biotechnology risk assessment in Arabidopsis thaliana, Solanum lycopersicum, Sorghum bicolor and Zea mays.

Research Focus

The emphasis of my research program is to understand the genetic and environmental factors that influence nutritional quality. The focus of my work at this time is to identify factors that increase iron nutritional quality in maize grain. The improvement of nutritional quality in crops is often called biofortification. We have identified a mechanism to biofortify maize grain with iron using a human cell culture bioassay developed by my collaborator Ray Glahn as a phenotyping tool. We have taken this trait data, mapped quantitative trait loci for iron nutritional quality, and created new varieties. With help from the Glahn Laboratory, we have validated our results using poultry feeding studies and will soon begin metabolomic analysis of these new varieties. The previous focus for my research was assessing unintended effects of transgenic crop improvement on plant composition, quality and performance. According to the National Agricultural Statistical Service, transgenic crops made up a majority of US acreage planted in 2007. In spite of this (or perhaps because of this), a debate exists between supporters and opponents of transgenic crops regarding the demonstrated or presumed safety of these varieties to people, animals and the environment. Two important concepts in the debate over transgenic crop safety are substantial equivalence (SE) and generally regarded as safe (GRAS). SE is the concept that a transgenic variety is so highly similar to its non-transgenic parent, that it can be considered to be the same. Opponents of transgenic crop improvement have criticized this concept for being without statistical merit or utility for risk assessment. In the plant improvement context, GRAS means that we accept that the products of conventional plant breeding (i.e., new varieties) are safe. Thus, the differences that exist between conventionally improved plant cultivars represent a threshold that is acceptable to consumers, regulators and other stakeholders. We examined the differences between conventionally and transgenically modified varieties from a standpoint of GRAS, to evaluate SE in a statistically rigorous manner. My laboratory used fruit ripening in tomato as a model system of known agronomic importance and use a number of experimental approaches.

Outreach and Extension Focus

I am very active in school and community gardening, through the USDA's People's Garden Initiative. In 2011, I organized a donation garden that gave 15,500 lb of fresh produce to Tompkins County food pantries. I have also been a key player in developing the garden at the Cornell Child Care Center.

Teaching Focus

I have been interested in genetics for many years. I am also fascinated by connections, relationships and context. I try to convey my enthusiasm for genetics, plus the need for context, in my teaching.

Additional Links

• Department of Plant Breeding and Genetics
• Boyce Thompson Institute website
• USDA ARS
• Link to CALS Research and Impact
• Link to Research & Expertise Across Cornell

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