نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه فنی کشاورزی، دانشکده فناوری کشاورزی، دانشگاه تهران، تهران، ایران
2 2. گروه فنی کشاورزی ، دانشکده فناوری ابوریحان -دانشگاه تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Cavitation, which involves the formation of air bubbles in plant xylem, significantly impairs water transport, affecting a plant's ability to move water effectively. This phenomenon is primarily caused by water vapor, air intrusion, and is often exacerbated by drought conditions in summer, freezing temperatures in winter, and physical damage to the plant. Traditional methods for measuring cavitation are labor-intensive and require extensive laboratory sampling. This study presents an automated pneumatic system designed to directly measure cavitation resistance in plant xylem. The system includes an electronic circuit, a pressure sensor, a vacuum pump, and pneumatic connections, enabling it to evaluate the plant's response to negative pressure, with leaf potential assessed using a psychrometer. We conducted tests on seven samples each of the "Mashhad walnut cluster genotype" and the "Iran walnut genotype," with three replicates for each. The system successfully generated vulnerability curves and compared plant samples under both laboratory and field conditions. Results indicated that the Mashhad cluster walnut genotype demonstrated greater cavitation resistance compared to the Iranian walnut genotype. These findings highlight the pneumatic system's efficiency and speed in assessing pore resistance in plants, contributing significantly to research aimed at improving plant water transport systems and physiological performance, making it a valuable tool for both laboratory and field studies in plant physiology.
کلیدواژهها [English]
EXTENDED ABSTRACT
Drought stress in summer, freezing conditions in winter, and physical damage can lead to cavitation in plants. Blocked vascular channels diminish the plant's hydraulic capacity and hinder photosynthesis. Stress-induced cavitation is affected by water availability and transpiration levels, ultimately reducing water transport capacity, impairing plant performance, and potentially causing plant death. While various methods to measure cavitation exist, they are often time-consuming and require large samples. This research developed the penomatic method, a rapid technique that requires fewer samples.
This study presents an automated system for measuring plant pneumatic cavitation, consisting of an electronic circuit, pressure sensor, vacuum pump, and pneumatic connectors. This robust tool effectively investigates plant-water relationships and gas exchange, notably enabling accurate and automatic measurement of gas emissions, including gas volume in both intact and embolized channels. To validate the device, experiments were performed on seven samples each of the "Khosheh Mashhad" and "Iranian" walnut genotypes, with three replications for each.
System calibration involved comparing voltage readings from the sensor with pressure values from a manometer. The resulting ratio was implemented in Arduino programming to ensure accurate pressure data recording and display. By integrating this system with a leaf water potential device, a fully automated setup for generating precise vulnerability curves was established for both laboratory and field conditions. This setup allows for accurate plotting of air discharge rate (ADrate) and air discharge volume (AD) graphs. The combination with portable leaf water potential measuring devices further enhances the automation of obtaining vulnerability curves in various environments. The system's low energy consumption compared to similar methods is a significant benefit, enabling the measurement of multiple samples or plant organs (e.g., roots, stems, and leaves) for comparative analysis. The findings indicated that the Khosheh Mashhad genotype showed greater resistance to cavitation than the Iranian walnut genotype.
High-resolution measurements allow for easy and efficient assessment of emboli resistance. Vulnerability curves were used to assess resistance to drought stress, indicating a reduction in air release rate due to water deficit that eventually stabilized. This stabilization indicated a threshold at which specimens showed resilience to further water deficit. Vulnerability curves revealed variation in emboli formation among species, with some maintaining hydraulic conductivity during prolonged drought, indicating physiological adaptation.
“Conceptualization, G.R. Chegini and H.R. Bakhshi; methodology, G.R.Chegini; software, H.R. Bakhshi; validation, H.R. Bakhshi, G.R.Chegini and A.Arabhosseini; formal analysis, H.R. Bakhsh.; investigation, G.R.Chegini; resources, A.Arabhosseini; data curation, H.R. Bakhsh.; writing—original draft preparation, H.R. Bakhshi; writing—review and editing, G.R.Chegini and A.Arabhosseini; visualization, A.Arabhosseini; supervision, G.R.Chegini; project administration, G.R.Chegini; funding acquisition, H.R. Bakhshi. All authors have read and agreed to the published version of the manuscript.”
The measured data from the agrotechnology department located in the college of technology of aboreihan was used.
The authors would like to acknowledge the generous assistance of Dr. Sarikahni, the senior of horticulture laboratory, as well as the agricultural technical group.
The authors would like to thank all participants of the present study.
The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
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