The fungal endophytes: does the rate of mycelium growth decrease with host age and host generations?

Fungal endophyte Epichloë poae shows a 50% decrease in mycelium growth rate with host plant age and successive generations in vitro.

• Why it matters: Understanding how fungal growth rates decline is crucial because it affects the efficiency of vertical transmission and seed colonization, impacting plant-endophyte symbiosis stability.
• What they did: Researchers passaged fungal mycelium in vitro to simulate vertical transmission, measuring growth rates across different host ages and generations, and comparing isolates from first and second generations.
• The result: The study found that fungal growth rates decline with host age and generations, suggesting growth rate as a potential indicator of the endophyte’s ability to colonize seeds and maintain symbiosis.