ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Technical Advances in Plant Science
Volume 16 - 2025 | doi: 10.3389/fpls.2025.1670504
From Osmotic Imbalance to Germination Arrest: Key Physiological Nodes in the Drought-Alkaline Interaction of Purple Alfalfa
Provisionally accepted
- Guizhou Normal University Karst Research Institute, Guiyang, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Alfalfa (Medicago sativa L.) is often constrained by factors such as drought and salinity-alkalinity in cultivation. This study aims to investigate the differential response characteristics and physiological-ecological mechanisms of alfalfa during the germination stage under drought, bicarbonate, and drought-salt combined stress. Drought stress was simulated using PEG-6000 (0– 20%), and salinity-alkalinity stress was simulated using NaHCO₃ (0–30 mM) to conduct germination tests on 12 alfalfa varieties. Based on the semi-inhibitory concentrations of germination and phenotypic indicators of the 12 alfalfa varieties under either drought or bicarbonate stress, drought-salt combined stress was applied. A membership function method was used to comprehensively evaluate the differential responses of the 12 alfalfa varieties to drought and salinity during germination, as well as the physiological-ecological response mechanisms of drought-tolerant, salt-tolerant, and drought-salt sensitive varieties. (1) There were significant differences among varieties in response to single drought or bicarbonate, identifying drought-tolerant varieties WL440HQ and WL363HQ, salt-tolerant variety WL525HQ, drought-sensitive 30°N, and salt-sensitive WL343HQ. Comprehensive evaluation indicated that the strongest and weakest drought and salt-resistant varieties were WL363HQ and WL319HQ, respectively; (2) Drought-salt combined stress exhibited antagonism at low concentrations and synergism at high concentrations; (3) The drought-salt tolerant variety WL363HQ adapted well to the combined stress through mechanisms involving SOD activity and soluble sugars, while the sensitive variety WL319HQ performed poorly. This study provides a scientific basis for elucidating the germination response mechanisms of plants under drought-salt combined stress and offers scientific support for planting in arid and saline-alkaline regions based on the selected drought-and salt-tolerant varieties.
Keywords: alfalfa, Drought stress, bicarbonate stress, Drought-Salt Combined Stress Effect, Germination Physiological Response
Received: 21 Jul 2025; Accepted: 10 Oct 2025.
Copyright: © 2025 Zhang, Hang, Wan, Guo and Li. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Hongtao Hang, hanghingtao86@126.com
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.