Ectomycorrhizal Community Structure of Salix and Betula spp. at a Saline Site in Central Poland in Relation to the Seasons and Soil Parameters

Abstract

Saline stress is one of the most important abiotic factors limiting the growth and development of plants and associated microorganisms. While the impact of salinity on associations of arbuscular fungi is relatively well understood, knowledge of the ectomycorrhizal (EM) fungi of trees growing on saline land is limited. The main objective of this study was to determine the density and diversity of EM fungi associated with three tree species, Salix alba, Salix caprea and Betula pendula, growing in saline soil during two seasons, autumn and spring. The site was located in central Poland, and the increased salinity of the soil was of anthropogenic origin from soda production. The degree of EM colonisation of fine root tips varied between 9 and 34 % and depended on the tree species of interest (S. caprea < S. alba < B. pendula) and season (spring < autumn). Moreover, the ectomycorrhizal colonisation of B. pendula was positively correlated with pH and CaCO3, while for S. caprea and S. alba, colonisation was associated with most of the other soil parameters investigated; e.g. salinity, Corg and N. Analysis of EM fungi revealed four to five different morphotypes per each season: Tomentella sp. Sa-A, Hebeloma collariatum Sc-A, Geopora sp. Sc-A, Helotiales sp. Bp-A in the autumn and Tomentella sp. Sa-S, Tomentella sp. Sc-S and three morphotypes from the families Thelephoraceae and Pyronemataceae in the spring. In conclusion, the density of EM is related to the level of salinity (ECe), season and tree species. Tomentella spp., Hebeloma sp., Geopora sp. and Helotiales sp. are groups of species highly adapted to saline conditions.

Impact of soil salinity on arbuscular mycorrhizal fungi biodiversity and microflora biomass associated with Tamarix articulata Vahll rhizosphere in arid and semi-arid Algerian areas

“…Furthermore, our findings pointed out that ectomycorrhizal and saprotrophic fungal biomasses decreased when soil salinity increased, as measured by ergosterol content, the specific lipid biomarker of those fungi categories (Wichern et al, 2006;Ben-David et al, 2011). Ishida et al (2009) and Hrynkiewicz et al (2015) recorded relatively low frequency of ectomycorrhizal fungi in saline soils. Likewise, for saprotrophic fungi, Zizzo (2009) observed a decrease in growth and in hyphal density of four studied saprotrophic fungi in saline soil (Laetiporus sulphureus, Ganoderma lucidum, Trametes versicolor and Pleurotus ostreatus).…”

“…Hyperosmotic stress in fungi is associated with inhibition of cell wall extension and cellular expansion, leading to a growth reduction. Moreover, an excess of Na + and/or Cl − ions in fungal cells may alter enzymatic activity and nucleic acid structure decreasing the potential of ectomycorrhizal fungi for successful colonization of the plant roots (Bois et al, 2006;Hrynkiewicz et al, 2015).…”

Ectomycorrhizal and endophytic fungi associated with Alnus glutinosa growing in a saline area of central Poland

“…The analysis was performed as described by Hrynkiewicz et al ( 2009 , 2015 ). The number of living non-colonized root tips versus the visually colonized EM root tips was counted using the formula: root tips × 100% / total number of root tips (Agerer 1991 ).…”

“…The fungal taxa were identified based on the internal transcribed spacer (ITS) region of the rDNA. The PCR analysis and the DNA sequencing were conducted as described by Hrynkiewicz et al ( 2009 , 2015 ). The identification process required a minimum of 98% similarity to the sequence investigated with reference sequences deposited in GenBank and/or the UNITE nucleotide database.…”

“…Moreover, mycorrhizal fungi reduce osmotic stress on the soil by increasing both the efficiency of water uptake (Cabot et al 2014 ) and the synthesis of antioxidants, that in turn protect host plants against adverse ROS (reactive oxygen species) produced in response to salt stress (Cabot et al 2014 ; Chandrasekaran et al 2014 ). However, a high level of soil salinity may also have a negative impact on such EM associations as colonization capacity and the growth of fungal hyphae in the soil (Hameed et al 2014 ; Hrynkiewicz et al 2015 ). It has already been confirmed that the level of EM fungal colonization generally decreases with increasing substrate salinity in vitro and in situ (Aggarwal et al 2012 ).…”