Above – belowground multi-species interactions
can be mediated by plant secondary chemistry. To investigate selection on
secondary compounds in these above- and belowground interactions, we are using
two Californian vernal pool mesamint species of the
genus Pogogyne. Few studies have shown that
soil biota - plant interactions can affect pollination. Here, we tested 1)
whether plants respond to arbuscular mycorrhizal fungi (AMF), 2) whether they have different
volatile terpenoid chemotypes
3) whether AMF affect terpenoid composition and
concentration. 4) whether AMF and terpenoids
affect pollination. We found genetic variation in plant growth response to AMF
(Glomus
sp.). Some, but not all populations had increased growth with AMF. AMF had no
effect on volatile terpenoid composition but there
was a trend that terpenoid concentrations were higher
in plants growing without AMF. Plants growing with AMF had more flowers and
larger flowers compared to plants growing without AMF, indicating that AMF
could potentially affect pollination. Currently, we are testing how AMF and terpenoids are affecting pollination and plant fitness in
the field.