Intraspecific variation in plant-fungal interactions across tidal elevation in a salt marsh

Area of Science:

• Ecology
• Plant-microbe interactions
• Salt marsh ecosystems

Background:

• Interspecific interactions are influenced by environmental and genetic factors.
• Intraspecific variation within interacting species can significantly alter ecological relationships.
• Host plant and endosymbiont variation may affect above- and belowground interactions under varying environmental conditions.

Purpose of the Study:

• To investigate how intraspecific variation in Spartina alterniflora and its fungal endosymbiont Lulworthia affects their interactions.
• To understand the role of genetic diversity in mediating plant-fungal relationships within salt marsh environments.

Main Methods:

• A glasshouse experiment compared Spartina growth forms (tall and short) with different Lulworthia isolates.
• A laboratory experiment assessed Lulworthia growth rates across salinity gradients.
• Molecular analysis (SNP) was used to distinguish fungal isolates.

Main Results:

• Intraspecific variation in Lulworthia isolates led to distinct morphologies and salinity-dependent growth.
• Spartina origin (ecotype) influenced plant responses to fungal treatments.
• One Lulworthia isolate negatively impacted Spartina performance (density, height, biomass), especially in tall-form plants, while another showed neutral to positive effects.

Conclusions:

• Intraspecific variation in both host plants and fungal endosymbionts is crucial for shaping plant-fungal interactions.
• Genetic diversity within Spartina and Lulworthia influences the outcome of their interactions and the host plant's adaptive capacity to environmental shifts.