Host-Specific Effects of Arbuscular Mycorrhizal Fungi on Two Caragana Species in Desert Grassland

Arbuscular mycorrhizal fungi (AMF), which form symbioses with most land plants, could benefit their hosts and potentially play important roles in revegetation of degraded lands. However, their application in revegetation of desert grasslands still faces challenges and uncertainties due to the unclear specificity of AMF-plant interactions. Here, Caragana korshinskii and Caragana microphylla were inoculated with either conspecific (home) or heterospecific (away) AM fungal communities from the rhizosphere of three common plant species (C. korshinskii, C. microphylla and Hedysarum laeve) in Kubuqi Desert, China. AMF communities of the inocula and their home and away effects on growth and nutrition status of two Caragana species were examined. Results showed that AMF communities of the three inocula from C. korshinskii, H. laeve and C. microphylla were significantly different, and were characterized by high abundance of Diversispora, Archaeospora, and Glomus, respectively. The shoot biomass, photosynthetic rate, foliar N and P contents of C. korshinskii only significantly increased under home AMF inoculation by 167.10%, 73.55%, 9.24%, and 23.87%, respectively. However, no significant effects of AMF on C. microphylla growth were found, regardless of home or away AMF. Positive correlations between C. korshinskii biomass and the abundance of AMF genus Diversispora were found. Our study showed strong home advantage of using native AMF community to enhance C. korshinskii growth in the desert and presented a potentially efficient way to use native AMF in restoration practices.