aeciosporat

Aeciospores are the sexual propagules produced during the aecial stage of certain rust fungi (order Pucciniales). Many rust species have heteroecious life cycles, meaning they require two unrelated host plants to complete development. The stage that bears aecia, the aecial stage, forms on the alternate host and generates numerous aeciospores that are released to continue the cycle on the primary host.

The aecial stage typically occurs after the pathogen has completed its initial stage on the primary host and has migrated to the alternate host, often driven by seasonal conditions. On the alternate host, the fungus forms structures called aecia that produce aeciospores. These spores are released from mature aecia and then infect the primary host, where they initiate the next stage of infection (usually the uredial stage, producing urediniospores) that amplifies disease on the primary host before the cycle proceeds to other stages such as teliospores.

Morphology and timing of aeciospores vary among species, but their primary role is to bridge infection from the alternate host back to the primary host. Aecial infections contribute to the spread and epidemiology of rust diseases in crops and wild plants. Because the life cycle depends on both hosts, management often targets the alternate host to disrupt disease spread; a notable historical example is the removal of barberry species to help control stem rust of wheat caused by Puccinia graminis.

The term aeciosporat is used in some languages or contexts to refer to aeciospores collectively; in English, the standard term is aeciospores.