Morfogénesis de la fase sexual de los helechos epífitos Microgramma mortoniana y Pleopeltis macrocarpa (Polypodiaceae) reserva Natural Punta Lara, Buenos Aires, Argentina

Abstract

Sexual morphogenesis phase of the epiphytic ferns Microgramma mortoniana and Pleopeltis macrocarpa (Polypodiaceae) from Punta Lara Natural Reserve, Buenos Aires, Argentina. The Punta Lara Natural Reserve is located on the riverside of the La Plata River in the province of Buenos Aires, Argentina. It is the Southernmost relict in the world of subtropical riparian forest. The epiphytic ferns studied in this work belong to the Polypodiaceae family: Microgramma mortoniana and Pleopeltis macrocarpa. Plant communities are subject to high levels of anthropization and introduction of exotic species. The goals of this work are to provide information on the morphogenesis of epiphytic gametophytes and to extend knowledge of their life cycles, contributing to their conservation. Sowing was carried out in Dyer medium. In both species the spores are monolete, ellipsoidal, yellowish and with verrucate sculpture. The equatorial diameter is 60-61 μm, the polar diameter is 39-42 μm. The germination is the Vittaria type; in M. mortoniana occurs at 20 days, while in P. macrocarpa occurs at six days. The filaments are uniseriate of 3-6 cells in length. The gametophyte development is Drynaria type. The cordated form is given after 40 days. In M. mortoniana, buds originated after 40 days. In P. macrocarpa, after 120 days, clathrate trichomes scale-like appear mainly on the margins of the gametophyte. The gametangia are typical of leptosporangiate ferns. The sporophyte of M. mortoniana emerged after 120 days and that of P. macrocarpa arose after 500 days, its blades are simple, spatulate and unicellular and multicellular branching hairs were observed. The germination pattern, gametophyte development, the presence of a lipid globule in the prothalic cell and the formation of unicellular capitated hairs are relevant characters that could be considered for systematic group. The delay in the formation of sporophytes through sexual reproduction, allows us to infer that the success of their establishment in situ would be given by the vegetative reproduction through creeping rhizomes and buds of gametophytes. Rev. Biol. Trop. 66(3): 1078-1089. Epub 2018 September 01.

In vitro spore germination and early gametophyte development of Cibotium barometz (L.) J. Sm. in different media

“…Early gametophyte development stages of Cibotium barometz Gametophyte development of C. barometz in vitro culture is of the Drynaria-type (Nayar and Khaur 1969). The same type of gametophyte development is reported in Adiantum capillus-veneris L. (Oloyede et al 2017), Lepisorus nudus (Singh et al 2017), Microgramma mortoniana, and Pleopeltis macrocarpa (Gorrer et al 2018). As also described by Praptosuwiryo et al 2015, when at the fimentous stage (prothallus has 5-10 or more cells) one of the cells at the top margin of the prothallus (the anterior marginal cells) then divides obliquely across its width (Figure 1.C.).…”

“…Deng et al (2007) and Praptosuwiryo et al (2015) also reported only one type of spore germination of C. barometz, the Vittariatype. A similar types of spore germination also reported in Aglaomorpha cornucopia (Huang et al 2015), Lepisorus nudus (Singh et al 2017), Microgramma mortoniana and Pleopeltis macrocarpa (Gorrer et al 2018). Farfán-Santillán (2017) reported two types of germination of Gleichenia and Cyathea; and three types of prothallial development Marattia, Osmunda and Drynaria.…”

Atlas de esporas de helechos isosporados de la Reserva Natural Punta Lara, Argentina

“…Our studies in this area also included the reproductive aspects of some native ferns, as well as the analyzes of soil spore banks as contributions to biodiversity conservation in this area (Ramos Giacosa et al, 2014Luna et al, 2016;Ramos Giacosa et al, 2017;Gorrer et al, 2018).…”

“…ex Willd. (Gorrer et al, 2018), Amauropelta Kunze, Christella H. Lév. and Goniopteris C. Presl (=Thelypteris Schmidel) (Giudice et al, 2014;Ramos Giacosa et al, 2014).…”

Effects of the fungus Pestalotiopsis maculans (Ascomycota: Amphisphaeriales) on the gametophytic development of the fern Lygodium venustum (Lygodiaceae)

“…As part of a project to ascertain on the reproductive biology of native ferns in Argentina (Luna et al, 2016;Ramos Giacosa et al, 2017;Gorrer, Berrueta, Ramos Giacosa, Giudice, & Luna, 2018), a fungus was found during in vitro spore culture of L. venustum. After examining the sporophytes with magnifying glass, dark brown spots and eruptive pustules were observed in fertile leaves.…”