Major research themes of my career have been wide crosses, introgression, and new crop development. Relatives of domesticated plants represent a vast reservoir of potentially useful genes, but obtaining viable, fertile progeny from crosses between different species is often difficult. By understanding how genetics and environment affect the likelihood of obtaining interspecific or intergeneric progeny, one can more efficiently use natural germplasm resources to improve existing crops or to develop new ones. In past research, I have used such knowledge to introgress genes of interest, such as resistance to reniform nematodes into upland cotton, and to initiate the development of a new crop, perennial upland rice, for the erosion-prone uplands of Southeast Asia. My current work on perennial grasses builds upon these themes by developing new crops via wide crosses and direct domestication of wild species.
Annual grains are currently the foundation of the human food supply. Why annuals and not perennials? It was not the outcome of a carefully conceived plan but rather a consequence of selection by the first farmers. However, it should be possible to develop perennial grain crops by selecting concurrently for both yield and perennial growth. Such a goal is worth pursuing because perennial grain crops could provide enhanced ecosystem services, which would reduce the environmental and economic costs of food production. Recently, in collaboration with the Snapp lab at Michigan State University, I have started to study the effects of planting season, and timing of initial cutting on some of the first varieties of perennial rye, perennial wheat and intermediate wheatgrass. In the future, I plan to expand upon this initial research by breeding one or more perennial grain crops. Dual-use crops, such as grain and bioenergy, or grain and forage are also of interest.
Bioenergy crops can reduce our dependence on fossil fuels, help mitigate human-induced climate change, and bolster agriculture. Some perennial grasses have the potential to assimilate large amounts of CO2 from the atmosphere and this primarily cellulosic biomass can be used for energy by direct burning or by conversion to liquid fuels. Moreover, the underground shoots and roots of these perennial grasses help conserve and build soil, sequester carbon, and enable efficient use of nutrients and water. Crops that I am especially interested in include Miscanthus, prairie cordgrass (Spartina pectinata), big bluestem (Andropogon gerardii), miscanes (Miscanthus/Saccharum), and perennial interspecific Sorghum. These crops are in the initial stages of domestication. To build a useful resource base for crop improvement, I am collecting germplasm, phenotyping materials in replicated trials, and using molecular markers to study genetic diversity and population structure. My work on prairie cordgrass and big bluestem is in collaboration with DK Lee who initiated and leads efforts to collect and characterize these native prairie species. I am studying the genetics governing key traits of interest (e.g. adaptation, pest and disease resistance, yield, and quality) via molecular mapping and by using crossing designs to estimate genetic variances. Research to improve breeding efficiency of these new crops by quantifying the effects of different breeding and selection methods is also being conducted.