Phenotypic responses of barley to Akanthomyces muscarius inoculation are maintained in the offspring generation

Plant phenotypes are influenced by interactions among genetic, environmental, and microbial factors. Entomopathogenic fungi such as Akanthomyces muscarius are widely used in biological control, but their direct effects on plant growth and reproduction, independent of pest suppression, remain insufficiently understood. This study aimed to evaluate the effects of A. muscarius inoculation on the growth and reproductive parameters of barley (Hordeum vulgare L.) and to determine whether these effects are maintained in the offspring generation.

In the primary generation, inoculation with A. muscarius significantly affected plant performance in a cultivar-dependent manner. In 'Morex', inoculated plants showed reduced height but increased aboveground biomass and reproductive parameters. In 'Golden Promise', inoculation increased both shoot and root biomass without affecting plant height. Even though offspring plants were not reinoculated, selected phenotypic differences associated with maternal inoculation were observed in that generation. However, no culturable A. muscarius was detected in offspring leaves or seeds under the applied culture conditions.

Akanthomyces muscarius inoculation modified growth and reproductive parameters of barley and was associated with phenotypic differences in the offspring generation under controlled conditions. The underlying mechanisms remain unresolved and may involve intergenerational plasticity or other non-genetic maternal effects.