Changes in the mycorrhizal fungal community in host roots over five host generations under low and high phosphorus conditions

• Published in: Plant and soil Vol. 456; no. 1-2; pp. 27 - 41
• Main Authors: Liu, Shijun, Xu, Jing, Huang, Hong, Zhu, Jiani, Tang, Jianjun, Chen, Xin
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-11-2020; Springer
• Subjects: Beans; Biomedical and Life Sciences; Ecology; Legumes; Life Sciences; Mimosaceae; Plant Physiology; Plant Sciences; Regular Article; Soil Science & Conservation; Xu Jing; China; Mycorrhizal dependency; Low phosphorus environment; Host multi-generations; Community change; Arbuscular mycorrhizal fungi
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-020-04694-y

Aims
We tested whether arbuscular mycorrhizal fungal (AMF) community might shift as host plant generations advance under a low phosphorus (P) soil.
Methods
Two greenhouse experiments were conducted using
Medicago truncatula
as the host plant, six AMF species, and two soil P levels. Experiment 1 assessed changes in AMF composition in roots and soil during five generations of host plant grown in low-P (5.7 mg kg
−1
) and high-P soil (24.0 mg kg
−1
). Experiment 2 tested the effects of single AMF species on host plant growth in low-P and high-P soil.
Results
Experiment 1 showed that AMF species composition at the OTU level in roots and soil significantly changed as host generations advanced, and that the pattern of change differed in low-P vs. high-P soil. In low-P soil, the dominant OTU in both roots and soil shifted from OTU-50 (
Glomus tortuosum
) to OTU-49 (
Funneliformis geosporum
) as host generations advanced. In high-P soil, the AMF community in roots and soil was dominated by OTU-50 in first two generations but OTU-49 and OTU-50 were co-dominant in the last three generations. Experiment 2 showed that mycorrhizal dependency indices based on plant biomass and P content in plant biomass, and spore numbers were higher in host plants with
F. geosporum
than other AMF fungal treatments in low-P soil.
Conclusion
As the host
M. truncatula
grew in a low-P soil over five generations, AMF community in root and soil shifted to a composition with
F. geosporum
as dominant species who was effective in foraging for P.