Date Published: April 17, 2018
Publisher: Springer Berlin Heidelberg
Author(s): Mingchao Ma, Marc Ongena, Qingfeng Wang, Dawei Guan, Fengming Cao, Xin Jiang, Jun Li.
Arbuscular mycorrhizal fungi (AMF) play vital roles in sustaining soil productivity and plant communities. However, adaption and differentiation of AMF in response to commonly used fertilization remain poorly understood. In this study, we showed that the AMF community composition was primarily driven by soil physiochemical changes associated with chronic inorganic and organic fertilization of 37 years in Mollisols. High-throughput sequencing indicated that inorganic fertilizer negatively affected AMF diversity and richness, implying a reduction of mutualism in plant–AMF symbiosis; however, a reverse trend was observed for the application of inorganic fertilizer combined with manure. With regards to AMF community composition, order Glomerales was dominant, but varied significantly among different fertilization treatments. All fertilization treatments decreased family Glomeraceae and genus Funneliformis, while Rhizophagus abundance increased. Plant-growth-promoting-microorganisms of family Claroideoglomeraceae and genus Claroideoglomus were stimulated by manure application, and likely benefited pathogen suppression and phosphorus (P) acquisition. Family Gigasporaceae and genus Gigaspora were negatively correlated with available P in soil. Additionally, redundancy analysis further suggested that soil available P, organic matter and pH were the most important factors in shaping AMF community composition. These results provide strong evidence for niche differentiation of phylogenetically distinct AMF populations under different fertilization regimes. Manure likely contributes to restoration and maintenance of plant–AMF symbiosis, and the balanced fertilization would favor the growth of beneficial AMF communities as one optimized management in support of sustainable agriculture in Mollisols.
Arbuscular mycorrhizal fungi (AMF) are ubiquitous in terrestrial ecosystems. They are obligate plant root symbionts found in more than 80% of plant families (Mueller and Bohannan 2015) and they provide multiple benefits for both plant and AMF. For instance, AMF can provide plants with critical nutrients (Hodge et al. 2010) and non-nutrient benefits (Walder and van der Heijden 2015), help plants withstand drought (Li et al. 2013), develop soil aggregates (Rillig and Mummey 2006), stimulate photosynthesis (Kaschuk et al. 2009) and increase plant productivity (Maček et al. 2011), thereby influencing ecosystem processes and agricultural sustainability (Rillig 2004). Moreover, AMF confer resistance to plants against many soil-borne pathogens and various nematodes by their colonization of the plant root (Harrier and Watson 2004; Sikes et al. 2009). The plant, in turn, provides photosynthetic carbon (C) as an energy source for AMF, which can alter the fungal community (Kim et al. 2015). In addition to beneficial effects on plants, AMF also enhance ecosystem sustainability by influencing numerous soil properties and structure (Wilson et al. 2009), including soil stability (Mueller and Bohannan 2015), C storage (Treseder and Allen 2000), soil moisture (Johnson et al. 2003), and nitrogen (N), C and phosphorus (P) cycles (Van Der Heijden et al. 2008). Lower AMF biodiversity can also lead to unsustainable crop production and ecosystem instability (Maček et al. 2011). More importantly, the beneficial effects of AMF decrease under conditions of high fertility (Collins and Foster 2009). Although they are ubiquitous and of ecological importance, AMF have been poorly studied in the important black soils of China.