Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Putney, Katie [1], Chang, Shumei [2].

Do arbuscular mycorrhizal fungi communities play a role in the evolution of separate sexes in Geranium maculatum?

For gynodioecious plant species (both female and hermaphroditic plants in some populations), the establishment and success of females holds the key to our understanding of the evolution of separate sexes. One common pattern found in gynodioecious species is that females tend to become established in the “harsher” portion of their distribution. The Sex Differential Plasticity hypothesis suggests that females are more likely to establish in stressful environments, where hermaphrodites may allocate more resources to male function thus allowing females to exceed the threshold relative seed fitness they require to invade. We are exploring treating the available AMF partners in a site as environmental conditions to be considered for plant benefit. If AMF communities are important factors for female establishment, we predict that females may establish in populations with lower quality AMF partners. In a previous survey, we found that AMF community composition was significantly different between populations with females versus those without females, and to some extent may correlate with female frequency. In the current study, we followed up on these findings to ask: Do AMF communities collected from populations with females present (dimorphic) differ in their benefit to hermaphrodite plant growth and/or fitness than AMF inocula from populations without females present (monomorphic)? We addressed this question by conducting two factorial greenhouse experiments with all possible combinations of either rhizomes or seeds and AMF inocula from 6 monomorphic and 7 dimorphic populations of the gynodioecious plant species Geranium maculatum. We found that AMF from dimorphic soils were more beneficial for seedling aboveground biomass than AMF from monomorphic soils. We also found that whole soil inocula from dimorphic sites resulted in faster rhizome leaf rates than soils from monomorphic sites. Our findings show that neither AMF, nor soil biota as a whole, represent the harsh environmental conditions that allow for female establishment in some sites over others. Rather, we believe an evolutionary and/or ecological history between this plant species and the soil biota in these potentially stressful sites may have lead to a higher prevalence of soil biota that confer relatively greater benefits to plant growth in sexually dimorphic sites than in sexually monomorphic sites.

1 - University of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, Georgia, 30602, United States
2 - University Of Georgia, Plant Biology, 2502 Miller Plant Sciences, Athens, GA, 30602, USA

Keywords:
gynodioecy
plant-soil
Arbuscular mycorrhizae.

Presentation Type: Oral Paper
Session: 35, Symbioses: Plant, Animal, and Microbe Interactions
Location: 202/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 9:00 AM
Number: 35005
Abstract ID:693
Candidate for Awards:None