A team of researchers from the Danforth Plant Science Center, Saint Louis University and Washington University in St. Louis will focus on the importance of native North American crop wild relatives through a new collaboration. The researchers will develop an expanded vision for conservation of crop wild relatives in general, one that incorporates below-ground, as well as above-ground phenotypic variation in native species relevant for agriculture.

"This project represents an exciting collaboration between Washington University's Living Earth Collaborative, Saint Louis University, and the Danforth Plant Science Center,” said Allison Miller, Ph.D. Saint Louis University Department of Biology. “Domestication, the process by which wild plants evolve under artificial selection, has focused primarily on above-ground parts of the plant, usually grains for fruits, that are most immediately useful to people. Grapevines are one of 70 major crops that are grafted, which fuses one individual with a strong root system to a second individual that has desirable stem and fruit characteristics, to make a single individual vine that is joined at the stem. Here, we focus on wild species that have been selected for their root systems in order to understand how humans alter roots during domestication. This project will provide novel insights into natural variation in root systems and how that variability can be harnessed to develop resilient plants for future climates, from the ground up."

Genetic diversity is the foundation of evolution in nature and in domesticated systems. Recent advances in genomic data generation and ways of looking at plant anatomy have advanced current understanding of adaptation to a range of environmental conditions. In plant species, the vast majority of work has focused on observable variation in above-ground parts of the plant. Less well-known is variation in the below-ground portions of the plant, the root system. Using native North American grapevines as a model, the study will assess the following:

1. Variation among grapevine species in root structures;
2. Genomic differences among species that have evolved to inhabit unique soil types;
3. Effects of human selection on root morphology and genomic variation.

“Diversity is the foundation for change over time. By resequencing the genomes of a large number of grape rootstocks, we are piecing together the evolutionary changes leading to modern grapevine rootstocks that withstand disease and a changing climate," said Alex Harkess, National Science Foundation (NSF) plant genome initiative postdoctoral fellow in Dr. Blake Meyer’s Laboratory at the Danforth Center.

Researchers will generate germplasm resources, morphological data, and whole genome data from three wild grapevine species and their hybrid derivatives. Miller stated, “Funds will be used to collect the wild relatives of grapevine rootstocks found in the Central and Southern United States. We will compare root structure of these wild plants to selected rootstocks. We will also re-sequence genomes of major rootstock cultivars and their wild relatives in order to understand genomic changes associated with rootstock domestication."

The collaborative research will improve scientist’s understanding of natural variation and evolution in the less well-known half of plant diversity, the root system.