Life history of an endemic and threatened species: Pteris congesta

Abstract

Pteris congesta an endemic and endangered species was investigated to identify morphological differences between its sterile and fertile leaves. Our findings have unveiled, leaf dimorphism in both morphology and growth patterns between fertile and sterile leaves. The sterile leaves petioles exhibited equivalent growth to the laminae, achieving complete leaf expansion within a month. In contrast, the petioles of fertile leaves elongated more than twice the size of the leaf blades that remain closed for the initial 30 days. Spore germination was carried out in both sterile and non-sterile soils, and juvenile sporophytes were cultivated to allow for morphological comparisons with those collected from the wild. One month after sowing the spores germinated in both soils resulting in a uniseriate germ filament Vittaria-type, and differentiated into laminar gametophytes, forming a Ceratopteris-type prothallus. The first leaf of the sporophyte emerged two months after sowing, and its development was completed one month later. Based on our studies, we propose that seedlings cultivated from spores germinated in soil can be used for the reintroduction of endangered fern species.

Key words:
Atlantic Forest; conservation; gametophyte; sporophyte development; spore germination