Published In

Journal of Applied Botany and Food Quality

Document Type

Article

Publication Date

2018

Subjects

Soil salinization -- Effect of climatic changes on, Agricultural productivity, Nitrogen-fixing plants -- Costa Rica, Lima bean, Symbiosis

Abstract

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.

Description

© The Author(s) 2018. This is an Open Access article distributed under the terms of the Creative Commons Attribution Share-Alike License (http://creativecommons. org/licenses/by-sa/4.0/).

Originally appeared in Journal of Applied Botany and Food Quality, vol. 91, pages 304-409. Published by Julius Kühn-Institut - Bundesforschungsinstitut für Kulturpflanzen (Federal Research Centre for Cultivated Plants). May be found at https://doi.org/10.5073/JABFQ.2018.091.039.

DOI

10.5073/JABFQ.2018.091.039

Persistent Identifier

https://archives.pdx.edu/ds/psu/27184

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