Quantitative effects of soil salinity on the symbiosis of wild lima bean (Phaseolus lunatus L.) and Bradyrhizobium in Costa Rica
Effects of Salinity on Rhizobial Symbiosis
DOI:
https://doi.org/10.5073/JABFQ.2018.091.039Abstract
Global climate change and local anthropogenic activities are increasing soil salinization with permanent negative effects on agricultural and ecosystem productivity. While salt stress is known to affect plant performance, its effects on the association with key microbial plant symbionts, such as legume-associated nitrogen-fixing rhizobia, are less understood. In this field study conducted in Costa Rica (Puntarenas), we used sympatrically-occurring wild lima bean (Phaseolus lunatus L.) and Bradyrhizobium to quantify biomass production of unfertilized rhizobial (R+) and fertilized rhizobia-free (R-) plants at different levels of experimentally manipulated salinity in native soil. In response to salt stress, nodulation was significantly reduced even at slightly increased salt levels. Plants growing at soil salinity levels of 2, 4, 6, and 8 mS/cm showed a mean reduction of nodules by 60.22, 76.52, 83.98, and 92.5% compared to the controls. Similarly, we also observed a significant decline in plant biomass at elevated salinity. However, biomass accumulation of R- plants was significantly less impacted compared to R+ plants, suggesting that the plant-microbe symbiosis is more salt-sensitive than the plant host itself. We suggest that the search for more salt-tolerant, crop plant-compatible rhizobial strains may provide a sustainable approach to maintain agricultural productivity on low to moderately saline soils.
Downloads
Published
Issue
Section
License
From Volume 92 (2019) on, the content of the journal is licensed under the Creative Commons Attribution 4.0 License. Any user is free to share and adapt (remix, transform, build upon) the content as long as the original publication is attributed (authors, title, year, journal, issue, pages) and any changes are labelled.
The copyright of the published work remains with the authors. If you want to use published content beyond what the CC-BY license permits, please contact the corresponding author, whose contact information can be found on the last page of the respective article. In case you want to reproduce content from older issues (before CC BY applied), please contact the corresponding author to ask for permission.