Abstract
Both mutualistic and pathogenic soil microbes are known to play important roles in shaping the fitness of plants, likely affecting plants at different life cycle stages.In order to investigate the differential effects of native soil mutualists and pathogens on plant fitness, we compared survival and reproduction of two annual tallgrass prairie plant species (Chamaecrista fasciculata and Coreopsis tinctoria) in a field study using 3 soil inocula treatments containing different compositions of microbes. The soil inocula types included fresh native whole soil taken from a remnant prairie containing both native mutualists and pathogens, soil enhanced with arbuscular mycorrhizal (AM) fungi derived from remnant prairies, and uninoculated controls.For both species, plants inoculated with native prairie AM fungi performed much better than those in uninoculated soil for all parts of the life cycle. Plants in the native whole prairie soil were either generally similar to plants in the uninoculated soil or had slightly higher survival or reproduction.Overall, these results suggest that native prairie AM fungi can have important positive effects on the fitness of early successional plants. As inclusion of prairie AM fungi and pathogens decreased plant fitness relative to prairie AM fungi alone, we expect that native pathogens also can have large effects on fitness of these annuals. Our findings support the use of AM fungi to enhance plant establishment in prairie restorations.
Highlights
Experimental and theoretical studies suggest that soil microbes play a central role in plant species coexistence and community structure (Bever, Mangan, & Alexander, 2015; Burns, Brandt, Murphy, Kaczowka, & Burke, 2017; Mangan, Herre, & Bever, 2010; Thrall, Bever, Mihail, & Alexander, 1997)
The soil inocula types included fresh native whole soil taken from a remnant prairie containing both native mutualists and pathogens, soil enhanced with arbuscular mycorrhizal (AM) fungi derived from remnant prairies, and uninoculated controls
Most work on plant–AM fungal interactions has focused on agronomic plants; there have been fewer studies of the effects of AM fungi on demography of wild plants
Summary
Experimental and theoretical studies suggest that soil microbes play a central role in plant species coexistence and community structure (Bever, Mangan, & Alexander, 2015; Burns, Brandt, Murphy, Kaczowka, & Burke, 2017; Mangan, Herre, & Bever, 2010; Thrall, Bever, Mihail, & Alexander, 1997). Complete studies of microbial effects on fitness should integrate survival and reproduction at different stages of the host organism's life (Antonovics & Alexander, 1989; Malmstrom & Alexander, 2016) Such studies are rare and are not trivial given that the soil microbiome includes diverse organisms and both mutualists and pathogens. Small never-plowed remnant prairies do occur with diverse plant and microbial species Reintroduction of these native prairie soil microbes, through either inoculation with AM fungi or wholesoil additions, can be important in establishing prairie plants in restoration sites in degraded postagricultural soils (Koziol et al, 2018; Lubin, Schultz, Bever, & Alexander, 2019; Middleton & Bever, 2012). A priori, we expected that plants grown with (a) native AM fungi-enhanced soil to perform better than those in postagricultural soil if AM fungi are acting as a mutualist in the former soil, (b) native AM fungi-enhanced soil to perform better than those in the native whole soil if negative effects of the pathogenic component of the native soil community are greater than positive effects of AM fungi, and (c) the native whole soil to perform better than those in postagricultural soil if the mutualistic component of the community is most prevalent (and the opposite to occur if pathogens dominate the interactions)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
