Collaborative Research: BTT EAGER: A wearable plant sensor for real-time monitoring of sap flow and stem diameter to accelerate breeding for water use efficiency

在不牺牲产量的情况下培育抗旱性更高的植物是全世界育种努力的一个主要目标。抗旱性与产量呈负相关关系。水从植物茎流向叶片的速率是解释不同植物品种间耐旱性差异的一个关键变量。然而，目前用于测量这种流速的技术体积庞大，如果长时间使用，可能会损坏电站；因此，他们无法在整个生长季节监测植物。此外，从当前传感器收集的数据需要测量阀杆尺寸，以便准确测量流量。如果茎在实验过程中生长，这些测量可能会引入误差。该项目开发了一种可穿戴植物传感器，可以对多种环境和基因型的流量进行准确的长期量化。大量的低成本传感器可以部署在育种计划中，从而可以直接评估品系。从这些品系中可以鉴定出在不同环境条件下控制液流率变异的特定遗传位点。同样，来自这些传感器的数据可以用于基因组预测模型，在投入资源进行实地试验之前优先考虑新的育种品系。这项研究将通过为工程和植物科学交叉的下一代研究人员提供研究机会来加强劳动力发展。该合作项目将整合传感器、微系统、纳米材料和植物科学方面的进展，实现一种新的液流测量方法，最终推进功能基因组学研究和耐旱作物的育种。目标是开发一种可穿戴的植物传感器，用于长期，准确和负担得起的监测整个生长季节的汁液流动。该传感器的设计可以有效地将微尺度液流传感单元与外部环境隔离开来，从而消除了传统的额外庞大的隔热装置的需要，并增加了对液流的响应。在阀杆周围对多个液流测量进行空间平均，提高了测量精度。利用传感器材料和结构的可拉伸性，将传感器对植物生长的物理约束降至最低，便于长期监测。提出的可穿戴传感器可以大规模低成本生产，使其能够纳入耐旱育种计划。最后，利用温室植物水分利用的重量测量方法对传感器进行表征、校准和验证。进行了初步的试点田间测量，将传感器应用于灌溉和非灌溉条件下种植的几种玉米杂交品种，这是内布拉斯加州对田间基因组的贡献（现有的公私合作伙伴关系）的一部分。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.