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Despite the evident importance of arbuscular mycorrhizal fungi (AMF) associated with the root system of plants inhabiting desert regions, limit is known about the distribution and activity of AMF in desert ecosystems. Accordingly, AMF diversity, community composition and glomalin were investigated in the northern desert of China. Soil samples from 0 to 30 cm in depth over seven plots were collected under the canopy of Hedysarum scoparium in July of 2015 and 2016. A total of 51 molecular operational taxonomic units (OTUs) were identified by MiSeq sequencing based on small subunit (SSU) ribosomal RNA genes, and Diversispora celata and Diversispora trimurales were discovered for the first time in a desert ecosystem in China. The abundant genera included Glomus (56.4%), Diversispora (25.1%), Claroideoglomus (6.0%), Funneliformis (6.1%) and Paraglomus (5.5%). Archaeospora and Scutellospora sequences represented

Dark septate endophytes (DSE) are diverse facultative biotrophic ascomycetes that ubiquitously colonise plant roots and may facilitate plant growth and productivity. However, the relationship between DSE resources and medicinal plants is still unclear. Here, we investigated DSE colonisation and species composition associated with roots of 25 medicinal plants collected from Anguo Medicine Planting Site in the farmland habitat, northern China in May 2017 using morphological characteristics and ITS sequencing. Typical DSE colonisation structures were observed in the roots of 25 medicinal plants. Total DSE colonisation was in the range of 2.22–100% and was significantly and positively correlated with soil organic matter, urease, and phosphatase. Host species purely explained 80.8%, 74.0%, and 79.0% of the observed variation in hyphal, microsclerotial, and total DSE colonisation, respectively. Of the 14 DSE taxa isolated from all 25 medicinal plant roots, six species were reported here for the first time in medicinal plants. Nonmetric multidimensional scaling analysis revealed that DSE colonisation and species composition significantly differed between different plant species. The DSE colonisation and species composition were predominately affected by plant identity than by soil factors. We conclude that the dynamics of DSE in the roots of medicinal plants exhibited a highly correlated plant species pattern, which further correlated with soil nutrient availability and enzymatic activity. This research provides a basis for further understanding of the ecological functions of DSE and their roles in the promotion of yield and quality of medicinal plants in the farmland ecosystems.

Arbuscular mycorrhizal (AM) fungi may facilitate the revegetation of degraded ecosystems by decreasing abiotic and biotic stresses on pioneer plants. In addition to assessing the AM status of pioneer plants, monitoring the dynamics of an AM fungal community after revegetation can provide key information for the selection of plant-AM fungal combinations that adapt to the disturbed conditions to promote the establishment and growth of mycorrhizal-dependent pioneer plants. Accordingly, species composition, diversity, and spore density of the AM fungal community inhabiting the root zones of 12-year- and 30-year-old planted Caragana microphylla were determined in the desertified grassland in northern China. Moreover, the content of glomalin-related soil proteins (GRSP) was measured to assess AM fungal biomass. A total of 23 AM fungal species belonging to Acaulospora, Claroideoglomus, Dentiscutata, Funneliformis, Glomus, Rhizophagus, and Septoglomus, were identified. Soil phosphorus availability or organic-carbon content significantly affected AM fungal composition and diversity. However, edaphic properties can explain only approximately 30% of the variations in the AM fungal community. Spore density and GRSP content recorded at the 30-year revegetated dune were significantly higher than those at the 12-year revegetated dune. No significant differences in community composition and diversity of AM fungi were recorded at the dunes with different revegetation duration. This indicates that there might be a certain degree of host-specificity existing in the C. microphylla-AM fungal association. Both taxonomic and phylogenetic analyses should be performed in further research to obtain comprehensive information about the composition and dynamics of an AM fungal community during revegetation of the desertified grassland.

Spatial dynamics of DSE in the roots and rhizospheres of Hedysarum scoparium Fisch. et Mey. and soil factors were investigated at seven arid and semi-arid locations in northwest China in July 2015. Sampling sites were found to have a significant influence on the morphology, components, distribution, and infection of DSE in the roots of H. scoparium . Of nine DSE species isolated from H. scoparium roots, five are reported here for the first time from desert ecosystems. Hyphal infection in roots was positively correlated with soil urease and phosphatase activity. The presence of microsclerotia in roots was positively correlated with soil ammonium, and negatively correlated with soil organic matter and pH. We conclude that DSE infection is spatially predictable, and is influenced by nutrient availability and enzymatic activity. This research provides a basis for further understanding the ecological functions of DSE, and their roles in the promotion of vegetation restoration and in reducing erosion and desertification in arid ecosystems.

Hedysarum scoparium, a species characterized by rapid growth and high drought resistance, has been used widely for vegetative restoration of arid regions in Northwest China that are prone to desertification. Desert soil is typically deficient in available water and the alleviation of drought stress to host plants by endophytes could be an efficient strategy to increase the success of desert restoration. With the objective to seek more beneficial symbionts that can be used in the revegetation strategies, we addressed the question whether H. scoparium can benefit from inoculation by dark septate endophytes (DSEs) isolated from other desert plants. We investigated the influences of four non-host DSE strains (Phialophora sp., Knufia sp., Leptosphaeria sp., and Embellisia chlamydospora) isolated from other desert plants on the performance of H. scoparium under different soil water conditions. Differences in plant performance, such as plant growth, antioxidant enzyme activities, carbon, nitrogen, and phosphorous concentration under all the treatments, were examined. Four DSE strains could colonize the roots of H. scoparium successfully, and they established a positive symbiosis with the host plants depending on DSE species and water availability. The greatest benefits of DSE inoculation occurred in water stress treatment. Specifically, Phialophora sp. and Leptosphaeria sp. improved the root biomass, total biomass, nutrient concentration, and antioxidant enzyme activities of host plants under water deficit conditions. These data contribute to the understanding of the ecological function of DSE fungi in drylands.

Dark septate endophytes (DSE) may facilitate plant growth and stress tolerance in stressful ecosystems. However, little is known about the response of plants to non-host DSE fungi isolated from other plants, especially under drought condition. This study aimed to seek and apply non-host DSE to evaluate their growth promoting effects in a desert species, Ammopiptanthus mongolicus, under drought condition. Nine DSE strains isolated from a super-xerophytic shrub, Gymnocarpos przewalskii, were identified and used as the non-host DSE. And DSE colonization rate (30–35%) and species composition in the roots of G. przewalskii were first reported. The inoculation results showed that all DSE strains were effective colonizers and formed a strain-dependent symbiosis with A. mongolicus. Specifically, one Darksidea strain, Knufia sp., and Leptosphaeria sp. increased the total biomass of A. mongolicus compared to non-inoculated plants. Two Paraconiothyrium strains, Phialophora sp., and Embellisia chlamydospora exhibited significantly positive effects on plant branch number, potassium and calcium content. Two Paraconiothyrium and Darksidea strains particularly decreased plant biomass or element content. As A. mongolicus plays important roles in fixing moving sand and delay desertification, the ability of certain DSE strains to promote desert plant growth indicates their potential use for vegetation recovery in arid environments.

Improved understanding of the spatial patterns of desert soil resources and the role of dark septate endophytes (DSE) is required to measure plant growth in desert areas. Spatial dynamics of DSE and soil factors were investigated in Wuhai, Urad Back Banner and Alxa Left Banner, located in Inner Mongolia, China. Soil samples in the rhizosphere of Ammopiptanthus mongolicus were collected. Sampling sites and soil depth had a significant influence on the morphology, distribution and infection of DSE. Hyphae, microsclerotia and total root infection of DSE reached their maxima in the 0–20 cm soil layer. Microsclerotial infection at Wuhai and Alxa Left Banner was higher than that at Urad Back Banner. Hyphal infection was significantly positively correlated with amounts of organic matter and available nitrogen, and activities of soil alkaline phosphatase, acid phosphatase and urease. Microsclerotial infection was significantly positively correlated with amounts of soil organic matter and available nitrogen. Root infection had no significant correlation with soil factors. We concluded that the dynamics of DSE have a highly spatial pattern, and were influenced by nutrient availability and enzymatic activity. This study suggests that the morphology and infection of DSE are useful indicators for evaluating soil quality and function of desert ecosystems.

The spatial diversity and distribution of AM fungi were investigated in three plots located in farming–pastoral zone, north China. The rhizospheres of Caragana korshinskii, Artemisia sphaerocephala and Salix psammophila were sampled and thirty AM fungal species belonging to five genera were isolated. The study demonstrated that AM fungal diversity and distribution differed significantly among the three host plants and the three studied plots. Spore density of AM fungi ranged between 2 and 22 spores per g−1 of soil and species richness between 8 and 23. Correlation coefficient analysis demonstrated that spore density was significantly and positively correlated with soil organic matter and available N (P

Tempo-spatial dynamics of AM fungi within the rhizome system of Psammochloa villosa (Poaceae) were investigated in Mu Us sandland, northwest China. Soil samples in the annual and perennial ramet rhizospheres of P . villosa were collected in 2007. AM fungal percent colonization reached maximal values in the rainy season and spore number in the dry season. Spore number exhibited positive correlation with soil pH and available phosphorous (P) ( P P P P Glomus was the predominant AM fungi, especially the small-spored taxa. AM fungal dynamics under P . villosa are highly seasonal: different aged ramets and nutrient availability have effects on AM fungal development and abundance in Mu Us sandland.

To understand the ecological significance of arbuscular mycorrhizal (AM) associations in semi-arid and arid lands, the temporal and spatial dynamics of AM fungi and glomalin were surveyed in Mu Us sandland, northwest China. Soil samples in the rhizosphere of Artemisia ordosica Krasch. were collected in May, July and October 2007, respectively. Arbuscular, hyphal and total root infection and spore density of AM fungi peaked in summer. The mean contents of total Bradford-reactive soil proteins (T-BRSPs, TG) and easily extractable Bradford-reactive soil proteins (EE-BRSPs, EEG) reached maximal values in spring. Spore density and two BRSPs fractions were the highest in the 0–10 cm soil layer, but the ratios of two BRSPs fractions to soil organic carbon (SOC) were the highest in the 30–50 cm soil layer. Hyphal infection was negatively correlated with soil enzymatic activity (soil urease and acid phosphatase) (P

To measure and manage plant growth in arid and semi-arid sandlands, improved understanding of the spatial patterns of desert soil resources and the role of arbuscular mycorrhizal (AM) fungi is needed. Spatial patterns of AM fungi, glomalin and soil enzyme activities were investigated in five plots located in the Mu Us sandland, northwestern China. Soils to 50 cm depth in the rhizosphere of Astragalus adsurgens Pall. were sampled. The study demonstrated that A. adsurgens Pall. could form strong symbiotic relationships with AM fungi. Arbuscular mycorrhizal fungal status and distributions were significantly different among the five studied plots. Correlation coefficient analysis demonstrated that spore density was significantly and positively correlated with soil organic carbon (SOC), soil acid phosphatase and to two Bradford-reactive soil protein (BRSP) fractions ( P −1 and 0.5 mg g −1 in all data, respectively. The levels of BRSP in the desert soil were little lower than those in native and arable soils, but the ratios of BRSP to SOC were much higher than farmland soils. The results of this study support the conclusion that glomalin could be an appropriate index related to the level of soil fertility, especially in desert soil. Moreover, AM fungal colonizations and glomalin might be useful to monitor desertification and soil degradation.

Biodiversity of arbuscular mycorrhizal colonization and spore density was investigated in 20 desert plants (dominant or common species) collected from different locations of Mu Us Sandy Land of China. We observed three mycorrhizal types including Arum-type, Paris-type, and an intermediate type among the plants. Another type of potentially beneficial fungi associated with roots of all species was also observed, namely, dark septate endophytic fungi (DSEF). Of the 20 sample plants examined, all species were coinfected by the two target fungi (Arbuscular mycorrhizal fungi (AMF) colonization of Salix psammophila and DSEF colonization of Periploca sepium were as low as 4%). Based on this investigation, we speculated that the DSEF are ubiquitous in desert ecosystems and can co-occur with AMF in desert plants, functioning much like mycorrhizal fungi. Further studies will be required to elucidate interactional mechanisms with AMF and the mechanisms operating in desert ecosystem.

The spatial variation of arbuscular mycorrhizal fungal spores under the canopy of Acacia raddiana was studied in a desert system. Soils samples from the base of the stem, its canopy radius, and outside its canopy at four stations in the Negev desert were collected from a 0 to 50 cm depth at sections of 10 cm each. The mean spore density was found to fluctuate between 265 100 g−1 to 105 100 g−1 in fluvisols and calcaric fluvisols, respectively. Our results suggest that spore density and spore distribution were found to be directly correlated with soil type, elucidating the importance of soil physical composition on AM fungi distribution in desert soil ecosystems.

The temporal and spatial dynamics of vesicular–arbuscular mycorrhizal (VAM) fungi were investigated in a desert ecosystem. Soil samples under the canopy of Zygophyllum dumosum were collected monthly between November 1999 and October 2000 from 0–10 and 10–20 cm depths. VAM fungal colonization and spore density were used to compare the responses of VAM fungi to soil conditions. The mean percent colonization and spore density of VAM fungi reached maximal values in November 1999 and September 2000. Soil moisture was positively correlated with colonization of VAM structure groups. Vesicular and arbuscular colonization were positively correlated with soil organic matter and total soluble N. Spore density was also positively correlated with total soluble N. Our results suggest that spore density and the extent of vesicular and arbuscular colonization are useful indicators for evaluating changes in desert soil ecosystems.

Despite the evident importance of arbuscular mycorrhizal fungi associated with the root system of plants inhabiting desert regions, the distribution and activity of arbuscular mycorrhizal fungi in desert ecosystems is not well known. In this study, the spatial distribution and colonization of arbuscular mycorrhizal fungi were investigated in a field study in the Negev Desert of Israel. Soil samples from depths of 0-10, 10-20, 20-30, 30-40, and 40-50cm were collected under the canopies of Zygophyllum dumosum, Hammada scoparia, Artemisia herba-alba , and Atriplex halimus . Spore density and association of vesicular root system with arbuscular mycorrhizal structure groups such as vesicles, arbuscules, and hyphae were used to assess and compare the responses of arbuscular mycorrhizal fungi to plant cover and their abiotic environment. Different plant cover significantly affected arbuscular mycorrhizal fungal colonization and spore density. Higher spore density tended to be correlated with higher arbuscular my...