Maternal effects shape the seed mycobiome in Quercus petraea

Area of Science:

• Ecology
• Mycology
• Forest Science

Background:

• The tree seed mycobiome's role in forest health and regeneration is understudied.
• Understanding fungal communities on seeds is crucial for forest ecosystem dynamics.

Purpose of the Study:

• To investigate the ecological processes shaping fungal communities on sessile oak seeds.
• To analyze how seeds acquire and maintain fungal communities from the mother plant to establishment.

Main Methods:

• Metabarcoding and confocal microscopy were used to analyze fungal communities.
• Seeds were sampled from the canopy and ground across four Quercus petraea populations.
• Joint species distribution models inferred ecological processes.

Main Results:

• Fungi were detected within internal seed tissues, including the embryo.
• Seed mycobiome composition varied significantly among populations and individual trees.
• Maternal influence was the dominant factor shaping the seed mycobiome, with minor environmental effects.
• Interactions between fungal pathogens and mycoparasites were identified.

Conclusions:

• Maternal effects, environmental filtering, and biotic interactions collectively shape the sessile oak seed mycobiome.
• Findings highlight the importance of maternal factors in vertical fungal transmission.
• This research provides a foundation for studying the impact of seed mycobiomes on germination and seedling recruitment.