Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Sublett, Jacob [1], Michaels, Helen J. [2].

Effects of Seed Coat Variation and Population in Lupinus perennis on Plant-Microbial Interactions.

Plants in the Fabaceae family are well known for their ability to form symbiotic relationships with rhizobia, which provide nitrogen to plants. The formation and ecological outcome of this partnership depends on the genotypes of both symbionts, along with abiotic and biotic factors in the environment. However, relatively few studies have examined the ecological factors that influence the distribution and abundance of this mutualistic relationship within natural ecosystems. Lupinus perennis is a Midwestern native legume found on dry, sandy soils supporting globally rare oak savannas and tallgrass prairies that vary in light and litter levels across its distribution. L. perennis seed coats are polymorphic in background color and speckling. These seed coat phenotypes, which are also correlated with changes in flavonoid biochemistry, vary in frequency both within and between populations. Here, we examine whether this seed coat variation is related to environmental differences between prairie and savanna habitats and can influence plant-microbe interactions. We hypothesized that dark seeds with higher concentrations of genistein (a flavonoid known to influence plant-microbial interactions) will have higher nodulation rates and larger seedlings. Alternatively, because differences in environmental factors are likely to affect microbial populations, this seed coat variation may also reflect habitat differences in the presence/abundance of rhizobia and pathogens within and among lupine populations.
To determine the effects of L. perennis seed coat phenotype variation, along with population and soil inoculum sources on seedling success and rhizobia recruitment, seeds from each of two populations were grown in each of four inoculum treatments, consisting of soil inoculums from grassland vs savanna habitats as well as positive and negative control treatments, in a controlled environment. After ten weeks we scored germination and final above and belowground biomass, along with number and dry mass of nodules. We found that effects of inoculum source and seed color on final seedling size and nodule mass were context dependent. However, only inoculum source affected nodule number. These data provide insight into the potential environmental and genetic factors that impact the distribution and abundance of potential rhizobial mutualists and antagonists, and help identify the evolutionary forces contributing to the maintenance of seed coat polymorphism in this native legume plant species.

1 - Bowling Green State University, Biology , Biological Sciences Department, Bowling Green, Ohio, 43403, USA
2 - BOWLING GREEN STATE UNIVERSTITY, Department Of Biological Sciences, Life Science Building, Bowling Green, OH, 43403, USA

Keywords:
mutualism
Legume-rhizobia
Seed Coat.

Presentation Type: Poster
Session: P, Symbioses: Plant, Animal, and Microbe Interactions Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PSB007
Abstract ID:777
Candidate for Awards:None