A symbiotic balancing act: arbuscular mycorrhizal specificity and specialist fungus gnat pollination in the mycoheterotrophic genus Thismia (Thismiaceae)

Mycorrhizal associations in mycoheterotrophic plants are generally more specialized than in autotrophs. Mycoheterotrophs typically bear small, inconspicuous flowers that often self-pollinate to maximize seed set, although some have structurally complex flowers indicative of xenogamy. A trade-off has previously been proposed between specialization in these above- and below-ground symbioses, although empirical data are lacking.We used...