Background:

Although there have been studies on the sexual phase of some species of Thelypteridaceae, none have included germination types and prothallial development.

Question:

Is there variation in the type of germination and prothallial development in the gametophytes of four species in the family Thelypteridaceae?

Study species:

Four species of the family Thelypteridaceae: Meniscium falcatum, Goniopteris mollis, Goniopteris liebmannii, and Goniopteris minor of the states of Chiapas, Oaxaca, and Tabasco.

Methods:

Spores were collected, sown in Petri dishes with Thompson culture medium, stored in transparent plastic bags, and placed in a plant growth chamber. The various stages of gametophyte development were fixed in FAA with 0.8 % sucrose, dehydrated in gradual alcohols, critical point dried, mounted on stubs, and coated with gold. The photomicrographs were obtained using a scanning electron microscope (SEM) Model Jeol JSM5310-LV.

Results:

The spores are monolete and perinate. Germination is of the Vittaria type, and prothallial development of the Aspidium type. Adult gametophytes are cordiform-spatulate, with numerous glandular, simple and single-celled hairs, antheridia and archegonia are of the leptosporangiate type. The first sporophyte leaf is bi or trilobate, with free dichotomous venation, with capitate-glandular hairs, simple, unicellular and acicular hairs, and hypostomatic polycytic stomata.

Conclusions:

The differences observed among the studied species are: spore size, perispore ornamentation, germination and emergence timing of the rhizoids, type and size of hairs, and development time of gametangia and sporophytes.

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