Breeding plants for increased drought resistance without sacrificing yield is a major goal of breeding efforts around the world. However, drought resistance and yield tend to be inversely correlated. The rate that water flows through the stalk of plants on its way to the leaves is a critical variable in explaining differences in drought tolerance between different varieties of plants. However, current technologies for measuring the rate of this flow are bulky and can damage the plant when they remain applied for long time periods; thus they are not able to monitor plants throughout a growing season. In addition, the data collected from current sensors requires measurements of stem size in order to accurately measure flow rates. If stems grow over the course of the experiment, these measurements can introduce error is. This project develops a wearable plant sensor that enables accurate long-term quantification of flow rates across many environments and genotypes. Large numbers of low-cost sensors can be deployed in breeding programs enabling direct evaluation of lines. From these lines specific genetic loci controlling variation in sap flow rates under different environmental conditions can be identified. Likewise data from these sensors can be used in genomic prediction models that prioritize new breeding lines prior to the investment of resources field trials. This research will enhance workforce development by providing research opportunities to next-generation researchers at the intersection of engineering and plant science.
This collaborative project will integrate advances in sensors, microsystems, nanomaterials, and plant sciences to realize a novel sap flow measurement method that ultimately advances functional genomics research and the breeding of drought tolerant crops. The objective is to develop a wearable plant sensor for long-term, accurate, and affordable monitoring of sap flow over an entire growing season. The sensor design allows efficient thermal insulation of the microscale sap flow sensing unit from external environments, thus eliminating the traditional need of additional bulky thermal insulation setup and increasing the response to sap flow. Spatial averaging of multiple sap flow measurements around the stem enhances measurement accuracy. By using stretchability of the sensor materials and structures, physical constraints of the sensor on plant growth is minimized for long-term monitoring. The proposed wearable sensors can be manufactured at large scale and low cost, allowing it to be incorporated into breeding programs tolerating drought tolerance. Lastly, the sensors are characterized, calibrated and validated over time using gravimetric measures of plant water use in the greenhouse. Initial pilot field measurements are performed, where the sensors are applied to several maize hybrids grown under irrigated and non-irrigated conditions as part of the Nebraska contribution to Genomes to Fields (an existing public-private partnership).
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
