“The planting of a tree, especially one of the long-living hardwood trees, is a gift which you can make to posterity at almost no cost and with almost no trouble, and if the tree takes root it will far outlive the visible effect of any of your other actions, good or evil.”
― George Orwell, A Good Word for the Vicar of Bray

Broadly, my research interests include perennial fruit and nut tree crop domestication, evolution, and germplasm and their use in plant breeding for increased pest, disease, and abiotic stress tolerance. I enjoy exploring these lines of inquiry to better understand genetic variation in germplasm and where selection has operated on the genome to identify loci of interest that may expedite breeding efforts in perennial crops. I feel this area is an important part of the broad efforts - such as regenerative and sustainable agriculture, agroecology, and integrated pest management - to reduce the impact of agriculure on the environment. My goal is for my research to be directly or indirectly applicable as an aid to farmers and gardeners.

Domestication of Tree Crops

Crop domestication is an area of study that seeks to understand not only how, but where and when, humans began cultivating and directing the evolution of a crop progenitor, as wll as how that domesticated species differs from its progenitor and wild relatives. Domestication in perennial crops is less clear as progenitor species are not always known, generation time complicates some methods of study and analysis, they retain a high degree of heterozygosity, and typically have a low degree of population structure compared to annual crops. To gain a deeper understanding of their origins, modifications leading to their present morphology, and when and where these processes occurred has direct implications for crop improvement. Identifying the extent of genetic diversity of the domesticated crop and their wild relatives and how it is expressed may contribute to crop improvement, understanding selection within the domesticate and its wild relatives and which are likely to result in genetic gains. I am currently investigating the demographic history or changes in population size and structure over time and selection in Prunus subgenus Amygdalus, the subgenus with almond and peach, using genomic data. I really enjoy working with Prunus subgenus Amygdalus as a study system for domestication, but also feel it is an excellent system for understanding adaptation and mating system differences in trees. The major questions I hope to answer are: (1) What is the relationship between species of subgenus Amygdalus?, (2) Does selection in the subgenus correspond to domestication status, climate, or matingy system?, and (3) How can genetic diversity of wild species in Prunus subgenus Amygdalus be utilized for crop improvement?

Rootstock Improvement

Rootstock are commonly used with perennial crops for improved resistance to soilborne pests and pathogens, resilience to abiotic stressors, difficult to root cultivars or species, or ease of rootstock propagation and grafting. Throughout history rootstocks have been generated as seedling populations from open pollination or specific hybrid crosses. More recently growers have increasingly adopted clonally propagated selections of intra- or inter-specific hybrids due to their more consistent performance. The goals of my research are to develop or aid in the development of improved clonal rootstocks for tree crops. Rootstock development in woody perennials requires careful planning due to their life cycle. Progeny testing to identify trees of interest for use in directed crosses. During and prior to my PhD, I made interspecific crosses of Juglans, Prunus, and Pistacia towards the efforts to identify a) novel individuals with superior performance to available rootstock varieties, b) generate populations gwas testing in collaboration with plant pathology screens, and c) identify trees within germplasm suitable for continued use in breeding efforts.

Tree Crop Germplasm