Several plants have evolved total dependence on fungal-derived energy sources and thus are termed as mycoheterotrophs. Mycoheterotrophy have been considered as the adaptation to thrive in low irradiance niches which poss few autotrophic competitors. However, once mycoheterotrophs had evolved, their distribution has been restricted to low irradiance environments which produce the unique mycorrhizal networks and microclimates necessary for their development.

Such an environment presents further problems on reproduction of plants because low irradiance habitats often have a negative effect on pollination success by reducing the frequency of pollinator. We aimed to investigate pollination biology of mycoheterotrophic orchid Gastrodia elata to reveal whether ecological constraints involving mycoheterotrophy (i.e., low irradiance habitat preference) has influence on their reproductive ecology.

As expected, the insect-mediated pollination success decrease in extreme low irradiance habitats. However, fruit set rates are not significantly different by light conduction because apomictic reproduction system works as insurance when insect-mediated pollination fails. Considering these facts, low-irradiance habitat preference which is ecological constraints involving mycoheterotrophy favor selfing strategy.