Alterations in Arbuscular Mycorrhizal Community Along a Chronosequence of Teak (Tectona grandis) Plantations in Tropical Forests of China

Arbuscular mycorrhizal (AM) fungi play a crucial role in promoting plant growth, enhancing plant stress resistance, and sustaining a healthy ecosystem. However, little is known about the mycorrhizal status of teak plantations. Here, we evaluated how the AM fungal communities of rhizosphere soils and roots respond to different stand ages of teak: 22, 35, 45, and 55-year-old from the adjacent native grassland (CK). A high-throughput sequencing method was used to compare the differences in soil and root AM fungal community structures. In combination with soil parameters, mechanisms driving the AM fungal community were revealed by redundancy analysis and the Mantel test. Additionally, spore density and colonization rates were analyzed. With increasing stand age, the AM fungal colonization rates and spore density increased linearly. Catalase activity and ammonium nitrogen content also increased, and soil organic carbon, total phosphorous, acid phosphatase activity, available potassium, and available phosphorus first increased and then decreased. Stand age significantly changed the structure of the AM fungal community but had no significant impact on the diversity of the AM fungal community. However, the diversity of the AM fungal community in soils was statistically higher than that in the roots. In total, nine and seven AM fungal genera were detected in the soil and root samples, respectively. The majority of sequences in soils and roots belonged to Glomus. Age-induced changes in soil properties could largely explain the alterations in the structure of the AM fungal community along a chronosequence, which included total potassium, carbon-nitrogen ratio, ammonium nitrogen, catalase, and acid phosphatase levels in soils and catalase, acid phosphatase, pH, and total potassium levels in roots. Soil nutrient availability and enzyme activity were the main driving factors regulating the shift in the AM fungal community structure along a chronosequence of the teak plantations.

Download Full-text

Increased precipitation, rather than warming, exerts a strong influence on arbuscular mycorrhizal fungal community in a semiarid steppe ecosystem

Botany ◽

10.1139/cjb-2015-0210 ◽

2016 ◽

Vol 94 (6) ◽

pp. 459-469 ◽

Cited By ~ 40

Author(s):

Cheng Gao ◽

Yong-Chan Kim ◽

Yong Zheng ◽

Wei Yang ◽

Liang Chen ◽

...

Keyword(s):

Fungal Community ◽

Water Availability ◽

Diversity Index ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Ecosystem Functions ◽

Spore Density ◽

Control Treatment ◽

Climate Change Scenarios ◽

Steppe Ecosystem

Knowing the responses of arbuscular mycorrhizal (AM) fungi to warming and increased precipitation are critical for understanding how biodiversity is maintained and how the ecosystem functions under global climate-change scenarios in natural ecosystems. In this study, AM fungal communities were examined in a 6 year experiment with warming and increased precipitation, in a semiarid steppe in northern China. Only the increased precipitation, regardless of warming, significantly increased AM fungal extra-radical hyphal density, compared with the control treatment. AM fungal spore density was significantly increased by the combination of warming and increased precipitation, and increased precipitation-only treatments, but not by warming alone. A total of 36 operational taxonomic units (OTUs) of AM fungi were recovered by 454 pyrosequencing of 18S rDNA. Only increased precipitation, regardless of warming, significantly decreased AM fungal OTU richness and Shannon diversity index, and yet significantly increased AM fungal Bray–Curtis dissimilarity index, compared with the control treatment. AM fungal community composition was significantly affected by increased precipitation via water availability, but not by warming. Our findings demonstrated that the AM fungal community responded more strongly to water availability than to warming in the semiarid steppe ecosystem.

Download Full-text

Effects of nitrogen deposition and phosphorus addition on arbuscular mycorrhizal fungi of Chinese fir (Cunninghamia lanceolata)

10.21203/rs.2.12558/v1 ◽

2019 ◽

Author(s):

Chuyu Lin ◽

Yaoxiong Wang ◽

Meihua Liu ◽

Quan Li ◽

Wenfa Xiao ◽

...

Keyword(s):

Mycorrhizal Fungi ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

N Deposition ◽

Relative Content ◽

Interactive Effects ◽

Spore Density ◽

Symbiotic Relationship ◽

P Addition ◽

Colonization Rates

Abstract Background Nitrogen (N) deposition is a key factor that affects terrestrial biogeochemical cycles with a growing trend, especially in the southeast region of China, where shortage of available phosphorus (P) is particularly acute and P has become a major factor limiting plant growth and productivity. Arbuscular mycorrhizal fungi (AMF) establish a mutualistic symbiosis with plants, and play an important role in enhancing plant stress resistance. However, the response of AMF to the combined effects of N deposition and P additions is poorly understood. Results Our results showed that N deposition significantly increased AMF root colonization rates and spore density, but inhibited both symbiotic relationship and spore propagation. In N-free plots, P addition significantly increased AMF root colonization rates, but did not significantly alter spore density. In low-N plots, AMF root colonization rates significantly decreased under low P addition, but significantly increased under high P addition, and spore density exhibited a significant decline under both low and high P additions. In high-N plots, AMF root colonization rates and spore density significantly increased under P additions. In general, AMF were closely related to the relative content of N and P in the soil. Interactive effects of simulated N deposition and P addition on both AMF root colonization rates and spore density were significant. AMF root colonization rates were significantly negatively correlated with soil moisture. Conclusions Moderate N deposition or P addition can weaken the symbiotic relationship between plants and AMF, significantly reducing AMF colonization rates and inhibiting spore propagation. However, a moderate addition of P greatly enhances spore yield. Soil moisture content is the main factor regulating AMF colonization rates. In the case of interactive effects, the AMF colonization rates and spore density are affected by the relative content of N and P in the soil.

Download Full-text

Arbuscular Mycorrhizal Fungi Symbiosis in Durum Wheat (Triticum durum Desf.) under No-tillage and Tillage Practices in a Semiarid Region

Agricultural Science Digest - A Research Journal ◽

10.18805/ag.d-339 ◽

2021 ◽

Author(s):

Mahieddine Sebbane ◽

Sonia Labidi ◽

Miloud Hafsi

Keyword(s):

Durum Wheat ◽

Mycorrhizal Fungi ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Conventional Tillage ◽

Spore Density ◽

No Tillage ◽

Tillage Practices ◽

Triticum Durum Desf ◽

Colonization Rates

Background: Arbuscular mycorrhizal fungi (AMF) are root symbionts that improve host plant growth and resilience against biotic and abiotic stresses allowing a sustain plant production particularly under harsh conditions. Methods: The objective of this study is to compare the effect of conventional tillage and no-tillage practices on AMF symbiosis with durum wheat (Triticum durum Desf) through the evaluation of root colonization and AMF spore density in the soil of three different sites in a semi-arid region in Algeria. Two sites were conducted under rain-fed conditions and one was irrigated.Result: Mycorrhizal root colonization varied according to the site and the tillage practice, while spore density differed between sites. Spore density was higher in sites under rain-fed conditions suggesting that water deficit stimulate sporulation, while root colonization seems to be limited by drought. No-tillage improved root colonization rates by 54.3% compared to conventional tillage system and this improvement, particularly the arbuscular percentage, was higher under drought conditions. In addition, root colonization rates showed a positive correlation with the organic matter content and pH in the soil and a negative correlation with the available phosphorus in the soil. These results indicate that no-tillage enhance the establishment of AMF symbiosis with durum wheat under semi-arid conditions.

Download Full-text

Effect of Septoria Leaf Blotch and its Control with Commercial Fungicides, on arbuscular-mycorrhizal-Fungal Colonization, Spore Numbers, and morphotype Diversity

Journal of Plant Protection Research ◽

10.2478/jppr-2014-0002 ◽

2014 ◽

Vol 54 (1) ◽

pp. 9-14 ◽

Cited By ~ 3

Author(s):

Santiago Schalamuk ◽

Silvana Velazquez ◽

María Rosa Simón ◽

Marta Cabello

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Spore Density ◽

Fungal Colonization ◽

Septoria Leaf Blotch ◽

Foliar Disease ◽

Leaf Blotch ◽

Carbon Supply ◽

Commercial Fungicide

Abstract Arbuscular-mycorrhizal internal structures (i.e. total root colonization, arbuscules, vesicles) and external structures (i.e. spore density), and Glomeromycota spore morphotypes, were evaluated in wheat severely infected with Mycosphaerella graminicola - the causal agent of Septoria leaf blotch. Plots in which the infection was controlled with a commercial fungicide at recommended field doses, were also examined. The commercial fungicide used was an admixture of trifloxistrobin and tebuconazole. No negative effects of the fungicide application on arbuscular-mycorrhizal fungi (AMF) were found. The M. graminicola fungicidal treatment actually favoured the formation of arbuscules and AMF spores, as there was a selective increase in the density of spores belonging to the glomoid morphotype. Arbuscular-mycorrhizal fungi have an absolute dependence on the carbon provided by the plant. A severe foliar disease leading to a diminished carbon supply to the roots would generate decreases in carbon availability. Such decreases would strongly affect mycorrhizal associations and development. Furthermore, the change in the green-leaf area produced by a severe foliar disease and/or a reversal of that condition through fungicide treatment could result in shifts in the composition of the AMF community so as to favour glomoid morphotypes. Glomoid species have been previously considered as r-strategists

Download Full-text

Studies on mycorrhizal biodiversity in medicinal plant species of Pookode Lake area, Wayanad, India.

Annals of Plant Sciences ◽

10.21746/aps.2017.6.12.6 ◽

2017 ◽

Vol 6 (12) ◽

pp. 1835

Author(s):

Saranya Babu Jayaprakash C.M. ◽

Nagarajan N.

Keyword(s):

Medicinal Plant ◽

Plant Species ◽

Centella Asiatica ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Medicinal Plant Species ◽

Spore Density ◽

Fungal Colonization ◽

Lake Area ◽

Mycorrhizal Association

Forty different medicinal plant species were investigated for arbuscular mycorrhizal association from Pookode Lake area, Wayanad district, Kerala. The spore density and percentage of infection varied with plant species. The percentage of AM fungal colonization ranged from 30 to 80. The highest AM fungal infection was exhibited in Centella asiatica (80%) and maximum spore population in Leucas aspera (690/100g). Totally 36 arbuscular mycorrhizal fungal species were recovered from the rhizosphere of 40 medicinal plant species belongs to 20 plant families. The arbuscular mycorrhizal spore species Glomus fasciculatum was found dominant.

Download Full-text

Dendrocalamus strictus ((Roxb.) Nees): A Suitable Host for the Maintenance and Propagation of AM Fungi under Temperate Conditions

ISRN Soil Science ◽

10.5402/2012/607213 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6

Author(s):

Shipra Singh ◽

Ajay Kumar ◽

Anita Pandey ◽

Lok Man S. Palni

Keyword(s):

Host Plant ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Dry Weight ◽

Spore Density ◽

Shoot Biomass ◽

Fungal Colonization ◽

Growth Enhancement ◽

Mycorrhizal Dependency ◽

Dendrocalamus Strictus

Dendrocalamus strictus ((Roxb.) Nees) was tested as a perennial host plant for propagation of an arbuscular mycorrhizal (AM) fungal consortium, initially isolated from rhizosphere of tea plants growing in the colder regions. The host performance in terms of colonization and spore production was compared with two annual hosts. The mycorrhizal dependency and growth enhancement potential were analyzed to test the suitability of D. strictus as a host plant. After 90 days of growth, 77.2% roots of D. strictus were found to be colonized by AM fungi with a spore count of 7 per g soil. AM fungal colonization and spore density values were lower in case of the host plants tested. Growth of D. strictus plants was found to be enhanced, in terms of all studied parameters; significant increases were recorded in shoot length as well as fresh and dry weight of shoots, a part of commercial importance. Similarly, P content, protein concentration, chlorophyll a and chlorophyll b contents were found to increase significantly. These data suggest that D. strictus can be used for the multiplication of AM fungi, isolated originally from the rhizosphere of tea; simultaneously, higher shoot biomass can provide additional economic benefit, using this environment friendly technology.

Download Full-text

Endophytic Fungal Root Colonization of Eragrostis tef in Eroded Croplands of the Ethiopian Highlands is Limited by Low Spore Density and Fertilisation

Agronomy ◽

10.3390/agronomy9020073 ◽

2019 ◽

Vol 9 (2) ◽

pp. 73 ◽

Cited By ~ 2

Author(s):

Gezahagn Getachew ◽

Boris Rewald ◽

Douglas L. Godbold ◽

Hans Sandén

Keyword(s):

Mycorrhizal Fungi ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Eastern Africa ◽

Eragrostis Tef ◽

Spore Density ◽

Ethiopian Highlands ◽

Set Up ◽

Spore Densities ◽

Colonization Rates

Eragrostis tef (teff) is a (sub-)tropical cereal crop and a staple food in Eastern Africa. As soil erosion has become increasingly worse in the Ethiopian highlands, we test the hypotheses that 1) eroded soils possess low arbuscular mycorrhizal fungi (AMF) spore densities, 2) teff growth is limited by low endophytic fungal root colonization rates and 3) colonization rates and spore densities are additionally reduced by fertilization. A pot experiment was set up to study the effect of cropland soil inoculation using pristine fungal communities (from adjacent forests) or fertilization. AMF spore densities in soil with and without teff and root colonization by AMF and dark septate endophytes (DSE) were related to straw and grain yields. AMF and DSE colonization rates were higher after inoculation, which provides evidence that a low spore density limits teff root colonization in eroded soils. However, teff yields were significantly increased after fertilisation but not inoculation. N-P fertilization further lowered root colonization rates and spore density. We conclude that forest soils serve as a refugium for soil biota in the degraded landscape of the Ethiopian highlands. As both increased AMF and DSE increase the stress resistance of plants, their inoculation potential should be considered when developing sustainable management methods for teff.

Download Full-text

Assessment of Arbuscular Mycorrhizal (AM) fungi of Glyphochloa santapaui: Vulnerable and endemic grass species of Maharashtra, India.

Annals of Plant Sciences ◽

10.21746/aps.2018.7.5.8 ◽

2018 ◽

Vol 7 (5) ◽

pp. 2251

Author(s):

Vishal Ramchandra Kamble ◽

Meghana M. Kolekar ◽

Sonali S. Lanjekar ◽

Yadvendradatta R. Yadav

Keyword(s):

Fungal Endophytes ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Fungal Species ◽

Iucn Red List ◽

Spore Density ◽

Grass Species ◽

Fungal Colonization ◽

Plant Soil ◽

Anthropogenic Threats

Glyphochloa santapaui (S.K. Jain & Deshp.) Clayton santapaui is endemic to Maharashtra state restricted to Ferricrete-Lateritic rocky plateaus at Sindhudurg and Ratnagiri district. Due to ongoing anthropogenic threats this species is rated as Vulnerable under IUCN Red List of Threatened Species and hence attention is needed toward its conservation.The lateritic plant-soil interactions in different taxa is dependent to their microbial or mycorrhizal associates. So far endemic grass species - Arbuscular mycorrhizal associations on Lateritic rocky plateaus are poorly investigated. In present paper critical assessment of AM fungal colonization in roots of vulnerable- endemic grass Glyphochloa santapaui is interpreted. Overall colonization percentage was 71.80%. Moreover, root segments of some samples were commonly co-colonized by dark septate hyphae (dsh) of other fungal endophytes (Ofe) and AM fungi. In present assessment, four Glomeromycota families viz., Acaulosporaceae, Diversisporaceae, Gigasporaceae and Glomeraceae were recorded comprising 18 species under 6 genera. These AM fungal species are viz., Acaulospora elegans, A. rehmii, A. scrobiculata, A. tuberculata, A. appendicula; Diversispora epigaea; Gigaspora albida, G. gigantea, G. margarita, G. rosea; Scutellospora calospora S. dipurpusescrns; Glomus gerdemanni, G. hoi, G. occultum, G. versiforme, G. warcuppi and Sclerocystis sinuosa. On the basis of analysis of spore density and relative abundance, two dominanting species of AM fungi viz., Diversispora epigaea and Gigaspora gigantea were recognized.

Download Full-text

Experimentally altered rainfall regimes and host root traits affect grassland arbuscular mycorrhizal fungal communities

10.32942/osf.io/cu4jh ◽

2019 ◽

Author(s):

Coline Deveautour ◽

Suzanne Donn ◽

Sally Power ◽

Kirk Barnett ◽

Jeff Powell

Keyword(s):

Fungal Community ◽

Community Assembly ◽

Root Length ◽

Specific Root Length ◽

Root Traits ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Rainfall Regime ◽

Precipitation Regimes ◽

Rainfall Regimes

Future climate scenarios predict changes in rainfall regimes. These changes are expected to affect plants via effects on the expression of root traits associated with water and nutrient uptake. Associated microorganisms may also respond to these new precipitation regimes, either directly in response to changes in the soil environment or indirectly in response to altered root trait expression. We characterised arbuscular mycorrhizal (AM) fungal communities in an Australian grassland exposed to experimentally altered rainfall regimes. We used Illumina sequencing to assess the responses of AM fungal communities associated with four plant species sampled in different watering treatments and evaluated the extent to which shifts were associated with changes in root traits. We observed that altered rainfall regimes affected the composition but not the richness of the AM fungal communities, and we found distinctive communities in the increased rainfall treatment. We found no evidence of altered rainfall regime effects via changes in host physiology because none of the studied traits were affected by changes in rainfall. However, specific root length was observed to correlate with AM fungal richness, while concentrations of phosphorus and calcium in root tissue and the proportion of root length allocated to fine roots were correlated to community composition. Our study provides evidence that climate change and its effects on rainfall may influence AM fungal community assembly, as do plant traits related to plant nutrition and water uptake. We did not find evidence that host responses to altered rainfall drive AM fungal community assembly in this grassland ecosystem.

Download Full-text

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

10.32942/osf.io/t82ug ◽

2019 ◽

Cited By ~ 1

Author(s):

Coline Deveautour ◽

Sally Power ◽

Kirk Barnett ◽

Raul Ochoa-Hueso ◽

Suzanne Donn ◽

...

Keyword(s):

Community Composition ◽

Plant Community ◽

Plant Communities ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Temporal Dynamics ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Plant Responses ◽

Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

Download Full-text