On the other hand, the requirement of bacteria for fruit
body initiation and further development is not absolute and
may be strain dependent. Among the A. bisporus isolates that
have been collected from the wild, some strains fruit readily
under axenic conditions (Kerrigan, 1995). These strains and
developmental mutants that are able to produce numerous
primordia under axenic conditions and become blocked at the pin stage, prove to be important research tools to study
factors that are involved in fruit body initiation (Elliott &
Wood, 1978 ; Hammond & Burton, 1996).