Nodule numbers, colonization rates, and carbon accumulations of white clover response of nitrogen and phosphorus starvation in the dual symbionts of rhizobial and arbuscular mycorrhizal fungi

Abstract

Leguminous plants can be dual colonized by rhizobia (Rh) and arbuscular mycorrhizal fungi (AMF). To test the affections of nodulation, colonization of AMF (AMF%) and the growth responses of white clover under crossed low nitrogen (N) and phosphorus (P) fertilization levels. The results showed that the nodule numbers were much more dense, significantly increased by AMF symbiosis, negatively controlled by the N levels but had no effect due to P levels. The influence of nodule numbers via AMF % was beyond P availability. The AMF% was related and favored with the better N and P nutrition, which may have better photosynthetic carbon (C) availability. The plant growth and C accumulation were significantly increased via rhizobium inoculation but were negatively affected by the AMF. The AMF colonization beyond P fertilization had strong effects on nodulation. Compared with rhizobium symbiosis, the AMF colonization requires a more C-composition between these two tertiary symbioses.

Keywords:

• arbuscular mycorrhizal symbiosis
• carbon costs
• nodulation
• dual symbiosis
• nitrogen
• phosphate

Acknowledgments

We are grateful for the fruitful discussion of Prof. YongGuan Zhu from Institute of Urban Environment, Chinese Academy of Science, Beijing China and his fully support on the experiment work.

Additional information

Funding

We are grateful for financial support from the project of Beijing Innovation Consortium of Agriculture Research System, project of BAIC01-2018; National Key Research and Development Program of China (2016YFD0201201).