Arbuscular mycorrhizal fungi assemblages in Chernozem great groups revealed by massively parallel pyrosequencing

2012 ◽  
Vol 58 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Mulan Dai ◽  
Chantal Hamel ◽  
Marc St. Arnaud ◽  
Yong He ◽  
Cynthia Grant ◽  
...  

The arbuscular mycorrhizal (AM) fungal resources present in wheat fields of the Canadian Prairie were explored using 454 pyrosequencing. Of the 33 dominant AM fungal operational taxonomic units (OTUs) found in the 76 wheat fields surveyed at anthesis in 2009, 14 clustered as Funneliformis – Rhizophagus, 16 as Claroideoglomus, and 3 as Diversisporales. An OTU of Funneliformis mosseae and one OTU of Diversisporales each accounted for approximately 16% of all AM fungal OTUs. The former was ubiquitous, and the latter was mainly restricted to the Black and Dark Brown Chernozems. AM fungal OTU community composition was better explained by the Chernozem great groups (P = 0.044) than by measured soil properties. Fifty-two percent of the AM fungal OTUs were unrelated to measured soil properties. Black Chernozems hosted the largest AM fungal OTU diversity and almost twice the number of AM fungal sequences seen in Dark Brown Chernozems, the great group ranking second for AM fungal sequence abundance. Brown Chernozems hosted the lowest AM fungal abundance and an AM fungal diversity as low as that seen in Gray soils. We concluded that Black Chernozems are most conducive to AM fungal proliferation. AM fungi are generally distributed according to Chernozem great groups in the Canadian Prairie, although some taxa are evenly distributed in all soil groups.

Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 689-701
Author(s):  
Xiaoge Han ◽  
Changchao Xu ◽  
Yutao Wang ◽  
Dan Huang ◽  
Qiang Fan ◽  
...  

AbstractWeed invasion is a prevailing problem in modestly managed lawns. Less attention has been given to the exploration of the role of arbuscular mycorrhizal fungi (AMF) under different invasion pressures from lawn weeds. We conducted a four-season investigation into a Zoysia tenuifolia Willd. ex Thiele (native turfgrass)–threeflower beggarweed [Desmodium triflorum (L.) DC.] (invasive weed) co-occurring lawn. The root mycorrhizal colonizations of the two plants, the soil AM fungal communities and the spore densities under five different coverage levels of D. triflorum were investigated. Desmodium triflorum showed significantly higher root hyphal and vesicular colonizations than those of Z. tenuifolia, while the root colonizations of both species varied significantly among seasons. The increased coverage of D. triflorum resulted in the following effects: (1) the spore density initially correlated with mycorrhizal colonizations of Z. tenuifolia but gradually correlated with those of D. triflorum. (2) Correlations among soil properties, spore densities, and mycorrhizal colonizations were more pronounced in the higher coverage levels. (3) Soil AMF community compositions and relative abundances of AMF operational taxonomic units changed markedly in response to the increased invasion pressure. The results provide strong evidence that D. triflorum possessed a more intense AMF infection than Z. tenuifolia, thus giving rise to the altered host contributions to sporulation, soil AMF communities, relations of soil properties, spore densities, and root colonizations of the two plants, all of which are pivotal for the successful invasion of D. triflorum in lawns.


2014 ◽  
Vol 60 (12) ◽  
pp. 819-827 ◽  
Author(s):  
R.P. Colombo ◽  
L. Fernández Bidondo ◽  
V.A. Silvani ◽  
M.B. Carbonetto ◽  
N. Rascovan ◽  
...  

The aim of this study was to assess the effects of agronomic practices on the arbuscular mycorrhizal (AM) fungal community in soils from the Pampa Ondulada region (Argentina), and to compare conclusions reached when using pyrosequencing or a morphological approach. The AM fungal diversity of 3 agricultural exploitations located in the Pampa Ondulada region (Argentina) was assessed by using 454 amplicon pyrosequencing and morphological (based on spore traits) approaches. Two kinds of soil managements are found in these sites: agronomic and non-agronomic. A total of 188 molecular operational taxonomic units and 29 morphological species of AM fungi were identified. No effect of soil management on AM richness was detected. AM fungal communities were more diverse and equitable in the absence of agronomic management. In contrast, the results on β-diversity varied according to the methodology used. We concluded that agronomic management of soil has a negative effect on AM fungal community biodiversity in the Pampa Ondulada region. We also conclude that both methodologies complement each other in the study of AM fungal ecology. This study greatly improved the knowledge about AM fungi in South America where the molecular diversity of AM fungi was practically unknown.


Fire ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 37
Author(s):  
Alícia Barraclough ◽  
Pål Olsson

Deforestation and the use of fire to clear land have drastic effects on ecosystem functioning and compromise essential ecosystem services, especially in low-income tropical countries such as Madagascar. We evaluated the effects of local slash-and-burn practices on soil nutrients and arbuscular mycorrhizal (AM) fungi abundance in a southwestern Madagascar forest. Nine sampling plot pairs were established along the border of a reserve within the Fiherenana–Manombo (pk-32) complex, where soil and seedling root samples of the endemic tree Didierea madagascariensis were taken. We analysed soil extractable PO43−, NH4+, and NO3− as well as total soil carbon and nitrogen. We analysed AM fungal abundance in soil and roots through fatty acid marker analysis (NLFA and PLFA 16:1ω5), spore extraction, and root staining. Slash-and-burn caused an increase in pH and doubled the plant available nutrients (from 7.4 to 13.1 µg PO43− g−1 and from 6.9 to 13.2 µg NO3− g−1). Total C and total N increased in deforested soil, from 0.6% to 0.84% and from 0.06% to 0.08%, respectively. There was a significant decline in AM fungi abundance in soil, with a decrease in soil NLFA 16:1ω5 from 0.2 to 0.12 nmol/g. AM fungi abundance in D. madagascariensis roots was also negatively affected and colonization decreased from 27.7% to 16.9% and NLFA 16:1ω5 decreased from 75.7 to 19 nmol/g. Together with hyphal network disruption, increased nutrient availability caused by burning is proposed as an explanation behind AM decline in soil and roots of D. madagascariensis. This is the first study to report the effects of slash-and-burn on AM symbiosis in Madagascar’s dry forests, with likely implications for other tropical and subtropical dryland forests worldwide where slash-and-burn is practiced.


2018 ◽  
Vol 6 (2) ◽  
pp. 37-43
Author(s):  
Lalnun thari ◽  
◽  
John Zothanzama

The study was conducted to assess the association of Arbuscular Mycorrhizal Fungi (AMF) in maize from three different jhum fallows. The jhum fallows are of three different years i.e., 1-3 years, 4-6 years and 7-10 years. Root samples were taken from maize to study colonization of AMF and spores were recovered from the rhizosphere region of the roots. It was observed that soil properties, rainfall pattern as well as human exploitation affect AMF colonization of roots.


Author(s):  
Sheng-Min Liang ◽  
Feng-Ling Zheng ◽  
Elsayed Fathi Abd_Allah ◽  
Pandiyan Muthuramalingam ◽  
Qiang-Sheng Wu ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.


2015 ◽  
Vol 43 (2) ◽  
pp. 488-493
Author(s):  
Zhaoyong SHI ◽  
Xubin YIN ◽  
Bede MICKAN ◽  
Fayuan WANG ◽  
Ying ZHANG ◽  
...  

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.


Author(s):  
Wei Fu ◽  
Baodong Chen ◽  
Matthias Rillig ◽  
Wang Ma ◽  
Chong Xu ◽  
...  

Mutualistic associations between plants and arbuscular mycorrhizal (AM) fungi may have profound influences on their response to climate changes. Existing theories evaluate the effects of interdependency and environmental filtering on plant-AM fungal community dynamics separately; however, abrupt environmental changes such as climate extremes can provoke duo-impacts on the metacommunity simultaneously. Here, we experimentally tested the relevance of plant and AM fungal community responses to extreme drought (chronic or intense) in a cold temperate grassland. Irrespective of drought intensities, plant species richness and productivity responses were significantly and positively correlated with AM fungal richness and also served as best predictors of AM fungal community shifts. Notably, the robustness of this community synergism increased with drought intensity, likely reflecting increased community interdependence. Network analysis showed a key role of Glomerales in AM fungal interaction with plants, suggesting specific plant-AM fungal pairing. Thus, community interdependence may underpin climate change impact on plant-AM fungal diversity patterns in grasslands.


Author(s):  
Jane Oja ◽  
Sakeenah Adenan ◽  
Abdel-Fattah Talaat ◽  
Juha Alatalo

A broad diversity of microorganisms can be found in soil, where they are essential for nutrient cycling and energy transfer. Recent high-throughput sequencing methods have greatly advanced our knowledge about how soil, climate and vegetation variables structure the composition of microbial communities in many world regions. However, we are lacking information from several regions in the world, e.g. Middle-East. We have collected soil from 19 different habitat types for studying the diversity and composition of soil microbial communities (both fungi and bacteria) in Qatar and determining which edaphic parameters exert the strongest influences on these communities. Preliminary results indicate that in overall bacteria are more abundant in soil than fungi and few sites have notably higher abundance of these microbes. In addition, we have detected some soil patameters, which tend to have reduced the overall fungal abundance and enhanced the presence of arbuscular mycorrhizal fungi and N-fixing bacteria. More detailed information on the diversity and composition of soil microbial communities is expected from the high-throughput sequenced data.


2021 ◽  
Vol 7 (8) ◽  
pp. 671
Author(s):  
Xiao Lou ◽  
Xiangyu Zhang ◽  
Yu Zhang ◽  
Ming Tang

The simultaneous effects of arbuscular mycorrhizal (AM) fungi and abscisic acid (ABA) on the tolerance of plants to heavy metal (HM) remain unclear. A pot experiment was carried out to clarify the effects of simultaneous applications of AM fungi and ABA on plant growth, Zn accumulation, endogenous ABA contents, proline metabolism, and the oxidative injury of black locust (Robinia pseudoacacia L.) exposed to excess Zn stress. The results suggested that exogenously applied ABA positively enhanced AM colonization, and that the growth of plants only with AM fungi was improved by ABA application. Under Zn stress, AM inoculation and ABA application increased the ABA content in the root/leaf (increased by 48–172% and 92%, respectively) and Zn content in the root/shoot (increased by 63–152% and 61%, respectively) in AM plants, but no similar trends were observed in NM plants. Additionally, exogenous ABA addition increased the proline contents of NM roots concomitantly with the activities of the related synthases, whereas it reduced the proline contents and the activity of Δ1-pyrroline-5-carboxylate synthetase in AM roots. Under Zn stress, AM inoculation and ABA application decreased H2O2 contents and the production rate of O2, to varying degrees. Furthermore, in the roots exposed to Zn stress, AM inoculation augmented the activities of SOD, CAT, POD and APX, and exogenously applied ABA increased the activities of SOD and POD. Overall, AM inoculation combined with ABA application might be beneficial to the survival of black locust under Zn stress by improving AM symbiosis, inhibiting the transport of Zn from the roots to the shoots, increasing the distribution of ABA in roots, and stimulating antioxidant defense systems.


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