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

培育在不牺牲产量的情况下提高抗旱性的植物是世界各地育种努力的主要目标。然而，抗旱性与产量呈负相关。水分在植物茎中流向叶片的速度是解释不同植物品种之间抗旱性差异的关键变量。然而，目前用于测量这种流动速度的技术很笨重，如果长期应用，可能会损害植物；因此，它们无法在整个生长季监测植物。此外，从电流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，这些测量就会引入误差。该项目开发了一种可穿戴的植物传感器，能够准确地长期量化多种环境和基因类型的流速。可以在育种计划中部署大量低成本传感器，从而实现对品系的直接评估。从这些品系中，可以确定控制不同环境条件下液流速率变化的特定遗传位点。同样，来自这些传感器的数据可以用于基因组预测模型，该模型在投资资源田间试验之前优先考虑新的育种品系。这项研究将通过向工程学和植物科学交叉点的下一代研究人员提供研究机会来促进劳动力发展。这个合作项目将整合传感器、微系统、纳米材料和植物科学的进展，实现一种新的树液流量测量方法，最终促进功能基因组学研究和耐旱作物的育种。其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的树液流动。传感器的设计使微型树液流量传感单元能够有效地隔热外部环境，从而消除了传统上需要额外的笨重的隔热设置，并提高了对树液流量的响应。树干周围多个树液流量测量的空间平均提高了测量精度。通过利用传感器材料和结构的可伸缩性，将传感器对植物生长的物理约束降至最低，以便进行长期监测。建议的可穿戴传感器可以大规模、低成本地制造，使其能够纳入耐旱育种计划。最后，使用温室植物用水的重力测量对传感器进行表征、校准和验证。进行了初步的试验性田间测量，将传感器应用于几个在灌溉和非灌溉条件下生长的玉米杂交种，作为内布拉斯加州对基因组到田间的贡献(现有的公私合作伙伴关系)的一部分。这一奖励反映了NSF的法定使命，并通过使用基金会的智力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.