Granados (CICESE) for the initial design of the microscope stands, and Alexis Crespo Michel (CICESE) for his assistance in developing the multi‐threaded version of the image capture Python program. DATA AVAILABILITY STATEMENT Data of all experiments are provided in the Supporting Information. The Python Program is available at: https://github.com/miguel-aalonso/lowcost_P50 . REFERENCES Angeles , G. , B. Bond , J. S. Boyer , T. Brodribb , J. R. Brooks , M. J. Burns , J. Cavender‐Bares , et al. 2004 . The cohesion‐tension theory . New Phytologist 163 : 451 – 452 . 33873751 10.1111/j.1469-8137.2004.01142.x Avila , R. T. , A. A. Cardoso , T. A. Batz , C. N. Kane , F. M. DaMatta , and S. A. McAda
Open resource ↗miguel-aalonso/lowcost_P50 · lines:264-337Paper record
A low-cost protocol for the optical method of vulnerability curves to calculate P 50 .
Applications in plant sciences · 31 Mar 2025 · 10.1002/aps3.70004
Abstract
Premise The quantification of plant drought resistance, particularly embolism formation, within and across species, is critical for ecosystem management and agriculture. We developed a cost-effective protocol to measure the water potential at which 50% of hydraulic conductivity ( P 50 ) is lost in stems, using affordable and accessible materials in comparison to the traditional optical method. Methods and results Our protocol uses inexpensive USB microscopes, which are secured along with the plants to a pegboard base to avoid movement. A Python program automatized the image acquisition. This method was applied to quantify P 50 in an exotic species ( Nicotiana glauca ) and native species ( Rhus integrifolia ) of the Mediterranean vegetation in Baja California, Mexico. Conclusions The intra- and interspecific patterns of variation in stem P 50 of N. glauca and R. integrifolia were obtained using the low-cost optical method with widely available and affordable materials that can be easily replicated for other species.
Code and data availability