Dioecious species and arbuscular mycorrhizal symbioses: the case of Antennaria dioica.

Sex-specific interactions with herbivores and pollinators have been observed in female and male plants of dioecious species. However, only a limited number of studies have revised sex-specific patterns in mycorrhizal symbiosis. To test whether female and male plants of Antennaria dioica differ in their relationship with arbuscular mycorrhizal (AM) fungi, we examined the temporal and spatial variation in AM fungi in female, male and non-reproductive A. dioica plants in three natural populations in Finland during flowering and after seed production. Our results are consistent with previous studies both under greenhouse and field conditions with the same species showing differences in AM colonization between the sexes linked with allocation to reproduction. Taken together, the results indicate that there is a sex-specific interaction between A. dioica and AM fungi. Overall, females have a greater investment in AM fungi, likely to enhance their uptake of soil nutrients and support the reproduction by seed.