CO2 is essential for colony initiation by flax rust fungus grown in vitro

Abstract

Cultures were grown under a constant stream of gas of known composition to eliminate accumulation of any volatiles produced by the fungus. CO2-free air completely inhibits colony initiation. Air containing 1% CO2 allows colony initiation to the same extent as occurs in plugged, nonaerated controls, while "normal air" (ca. 0.03% CO2) causes initiation to be delayed to a variable extent.