Higher temperatures and lower annual rainfall do not restrict, directly or indirectly, the mycorrhizal colonization of barley (Hordeum vulgare L.) under rainfed conditions.

Maroua Jerbi,Faysal Ben Jeddi,Hatem Chaar,Anissa Lounès-Hadj Sahraoui,Sonia Labidi

doi:10.1371/journal.pone.0241794

Abstract

Whereas the role of arbuscular mycorrhizal fungi (AMF) in plant growth improvement has been well described in agroecosystems, little is known about the effect of environmental factors on AMF root colonization status of barley, the fourth most important cereal crop all over the world. In order to understand the influence of environmental factors, such as climatic and soil physico-chemical properties, on the spontaneous mycorrhizal ability of barley (Hordeum vulgare L.), a field investigation was conducted in 31 different sites in sub-humid, upper and middle semi-arid areas of Northern Tunisia. Mycorrhizal root colonization of H. vulgare varied considerably among sites. Principal component analysis showed that barley mycorrhization is influenced by both climatic and edaphic factors. A partial least square structural equation modelling (PLS-SEM) revealed that 39% (R²) of the total variation in AMF mycorrhizal rate of barley roots was mainly explained by chemical soil properties and climatic characteristics. Whereas barley root mycorrhizal rates were inversely correlated with soil organic nitrogen (ON), available phosphorus amounts (P), altitude (Z), average annual rainfall (AAR), they were directly correlated with soil pH and temperature. Our results indicated that AMF root colonization of barley was strongly related to climatic characteristics than chemical soil properties. The current study highlights the importance of the PLS-SEM to understand the interactions between climate, soil properties and AMF symbiosis of barley in field conditions.

Highlights

Global climate models identified the Mediterranean region as one of the most vulnerable area to climate change [1]
One-way Analysis of Variance (ANOVA) showed that total colonization rates were significantly different between sampling sites
According to the one-way ANOVA, arbuscular colonization was significantly affected by sites

Summary

Introduction

Global climate models identified the Mediterranean region as one of the most vulnerable area to climate change [1]. In the Northern area of the country, barley is commonly grown on marginal soils under rainfed conditions (0.49 million hectares) [6] This area has a typical Mediterranean climate, characterized by dry summers with high temperatures and mild wet winters [9, 10]. Under such environmental conditions, some beneficial microorganisms such as Arbuscular Mycorrhizal Fungi (AMF) have been proven to provide many benefits to their host plants by (i) improving water and mineral nutrient uptake [11], (ii) increasing tolerance to biotic and abiotic stresses [12,13,14,15,16] and (iii) enhancing soil aggregation stability [17, 18]. The present work aims to analyze the effect of interactions between different groups of environmental factors (climate and soil physico-chemical properties) on AMF colonization status of barley (Hordeum vulgare L.), through the use of a Partial Least Square Structural Equation Modeling (PLS-SEM) method

Ethic statement

Results

Discussion

Conclusions