PS 43-138
Assessing the impact of phylogeny, plant traits and environmental factors on plant mycorrhizal responses
Plant response to AMF colonization is context-dependent, varying widely from mutualism to antagonism. Although plant mycorrhizal growth response (MGR) is influenced by both biotic and abiotic factors, their relative contributions are not clear. In a quantitative meta-analysis, I assessed the effects of environmental factors, plant traits and phylogenetic history on variation in plant MGR from 501 laboratory- and field-based studies. For each study, I collected 1) plant mycorrhizal growth responses (MGRs), 2) environmental factors (location, fertilizer, sterility, non-mycorrhizal filtrate), 3) plant traits (root colonization rate, seed mass), and 4) plant and AMF taxonomic data. A phylogenetic supertree was constructed using phyloGenerator with two genes (rbcL and matK). Classification and regression tree (CART) analysis and structural equation modelling (SEM) analysis were used to determine the relative importance of phylogeny, traits and environmental factors in explaining variation in MGRs.
Results/Conclusions
CART analysis revealed that plant species and plant families, respectively explain 77% and 21% of total variation are the most important factors in shaping plant MGRs. A phylogenetic signal (Lambda= 0.673, P<0.001) was found among MGRs. Results from SEM showed that root colonization, plant phylogenetic history, environmental factors respectively explained 31.5%, 2.82% and 1.61% variation in MGRs. These results indicate that interactions between plants and AMF are primarily driven by plants, regardless of the changes of other environmental factors and plant evolutionary history may play a role.