Biodiversity of arbuscular mycorrhizal fungi in the drawdown zone of the Three Gorges Reservoir under different fertilization histories

Abstract

Impoundment of the Three Gorges Reservoir (TGR) has dramatically influenced the riparian environment and shaped a new drawdown zone, which has experienced long‐term winter conditions and short periods of summer flooding. The community structure and diversity of arbuscular mycorrhizal (AM) fungi (AMF) were investigated in three areas with different fertilization histories [Area A (5 years of fertilization), Area B (3 years of fertilization) and Area C (no fertilization)] in the drawdown zone of the TGR. Altogether, 50 AMF species were identified; the genera Acaulospora, Funneliformis and Glomus were predominant. The AM fungal community differed among areas A, B and C. A higher isolation frequency and relative abundance of Acaulospora, Ambispora, Entrophospora and Paraglomus were observed in areas A and B; however, Claroideoglomus, Diversispora, Sclerocystis and Septoglomus were more abundant in Area C. The highest spore density occurred in Area C, and was slightly lower in Area A and lowest in Area B. Conversely, species richness and diversity indices (Shannon–Wiener and evenness indices) were the highest in Area A, followed by areas C and B. Based on nonmetric multidimensional scaling analyses, the distribution of AMF was influenced by plant host, fertilization practice and environmental factors. Among them, the soil physicochemical properties were the main drivers affecting AMF, in which three edaphic attributes (carbon/nitrogen ratio, available phosphorus and potassium content) were significantly correlated (P < 0.001) with the AM fungal community composition in the three areas of the drawdown zone of the TGR.

Fungal community profiles in agricultural soils of a long-term field trial under different tillage, fertilization and crop rotation conditions analyzed by high-throughput ITS-amplicon sequencing

“…The latter genus was only detectable within the ITS1 dataset and represented by two OTUs. A more recent study reported similar results [ 73 ]. Among areas with three different fertilization intensities for restoration of local plant communities, they also found Glomus and Funneliformis being the most predominant genera.…”

Arbuscular mycorrhizal fungi in a coastal wetland in Yucatan, Mexico

“…Recently, the use of molecular tools for identifying communities of AM fungi has been development. However, since there is still absence of uni- formity regarding the AMF-specific primer system that best reflect the diversity of AM fungi in a community (Kohout et al 2014), we decided to use the morphological characterization since we believe this approach remains valid to reach the aim of this study, as has been pointed out by other authors (v.g., Oehl et al 2004, Luo et al 2016.…”

Soil Organic Carbon Shapes AMF Communities in Soils and Roots of Cynodon dactylon under Anti-Seasonal Drying-Wetting Cycles

“…Interestingly, the population of the stoloniferous and rhizomatous C. dactylon, a widely distributed flooding-tolerant C 4 that is perennial in the drawdown zone of the TGR, has increased under the prolonged submergence and drying-wetting cycles since 2010 [23]. Apart from a strong growth performance, C. dactylon has shown high AMF colonization (15-54%) [23], which might contribute to improved vegetation restoration in the anti-seasonal drawdown zones of TGR [24]. Although the diversity and distribution patterns of AMF communities have been investigated in TGR [24] and wetlands [25][26][27][28][29], the responses of the AMF community of flooding-tolerant plants, including C. dactylon, to changes in soil property and land-use types under the drying-wetting alternations are still poorly understood.…”

“…Apart from a strong growth performance, C. dactylon has shown high AMF colonization (15-54%) [23], which might contribute to improved vegetation restoration in the anti-seasonal drawdown zones of TGR [24]. Although the diversity and distribution patterns of AMF communities have been investigated in TGR [24] and wetlands [25][26][27][28][29], the responses of the AMF community of flooding-tolerant plants, including C. dactylon, to changes in soil property and land-use types under the drying-wetting alternations are still poorly understood. Moreover, limited information is available if AMF occurrence and functioning are different between soils and roots, particularly under contrasting land-use changes [24,26].…”

“…Although the diversity and distribution patterns of AMF communities have been investigated in TGR [24] and wetlands [25][26][27][28][29], the responses of the AMF community of flooding-tolerant plants, including C. dactylon, to changes in soil property and land-use types under the drying-wetting alternations are still poorly understood. Moreover, limited information is available if AMF occurrence and functioning are different between soils and roots, particularly under contrasting land-use changes [24,26]. Therefore, we focused on the AMF community structure and diversity in the rhizosphere soils with those in the roots of C. dactylon under three contrasting land-use types of (1) NCND, (2) DNC, and (3) CL along the drawdown zone of the riparian banks in the TGR.…”